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stb/stb_voxel_render.h

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// @TODO
//
// - extend 2 bits below normal/texgen to support texture rotation
// - compute full set of texture normals
// - handle output buffer being full
// - gather vertex lighting from slopes correctly
// - support texture edge_clamp: explicitly mod texcoords by 1, use textureGrad to avoid
// mipmap articats. Need to do compute texcoords in vertex shader, offset towards
// center before modding, need 2 bits per vertex to know offset direction (is implicit
// implicit for modes without vertex data)
// - add 10-byte quad type (loses per-face tex1/tex2 blend mode)
// - add 6-byte quad type (loses baked ao, most geometry, flags, texlerp)
// - add 4-byte quad type (only texture or only color, no baked light, no recolor)
// stb_voxel_render.h - 0.01 - Sean Barrett, 2015
//
// This library helps render large "voxel" worlds for games,
// in this case one with blocks that can have textures and that
// can also be a few shapes other than cubes.
//
// It works by traditional rasterization, rendering the world
// as triangles.
//
// It provides:
//
// 1. a compact vertex data format (20 bytes per quad) to
// allow large view distances while still allowing a lot
// per-voxel variety and per-game/app variation
// 2. conversion from voxel data structure to vertex mesh
// 3. vertex & pixel shader
// 4. assistance in setting up shader state
// 5. planned support for much more compact vertex data formats
// (10, 6, and 4 bytes per quad) with more limited features.
//
// Although most of it is designed to be API-agnostic, the shaders
// are currently only in GLSL; the HLSL port will be along soon when
// someone else writes it.
//
//
// USAGE:
//
// #define the symbol STB_VOXEL_RENDER_IMPLEMENTATION in *one*
// C/C++ file before the #include of this file; the impleemtnation
// will be generated in that file.
//
// If you define the symbols STB_VOXEL_RENDER_STATIC, then the
// implementation will be private to that file.
//
//
// FEATURE SET:
//
// - voxels are mostly just cubes, but there is also
// support for half-height cubes and diagonal slopes,
// and half-height diagonals and even odder shapes
// for doing more-continuous "ground".
//
// - you can choose textured blocks or solid-colored voxels
//
// - if textured, each face specifies a base texture, chosen from
// up to 256 textures stored in a texture array. All the textures
// have be the same dimensions, but each texture can choose its
// scale: it can repeat every block, or it can be finer (e.g.
// repeat four times per block) or coarser (e.g. cover 4x4
// blocks).
//
// Texture coordinates are projections along one of the major
// axes.
//
// - a secondary texture: chosen from another set of 256 textures
// (or the same set, if you choose), which have all the same
// properties as above. these textures can be used to as
// detail textures, to apply decals, or to have lightmapping
// effects.
//
// - each face gets one of 64 colors; per face, this can modulate
// the primary texture, the secondary texture, or both.
//
// - if you disable textures, then each face gets a 24-bit rgb color
//
// - per face, you choose whether the secondary texture is
// alpha composited onto the first texture, or multiplies
// it (scaled up by 2, which can be used so that detail
// textures don't darken on average).
//
// - per vertex, you choose an extra alpha that controls the
// degree to which the secondary texture affects the primary;
// for example, this can be used to soften effects locally,
// or if both textures come from the same source, to transition
// between two textures
//
// - each vertex of each face computes a separate "lighting"
// value. this is typically essentially an ambient lighting
// value, which can be ambient occlusion, or baked local
// lighting, or etc.
//
// - per-pixel lighting is computed using a face normal and
// a single directional light combined with the baked occlusion.
//
// - per-face you can mark the face as being "fullbright",
// in which case it is drawn without any lighting faces
// (e.g. it's an emissive texture)
//
// - you can install a custom lighting function that takes the
// face normal & albedo color as input plus whatever uniforms
// you want.
//
// - the library generally takes care of coordinating the vertex
// format with the meshdata for you.
//
//
// VOXEL MESH API
//
// Context
//
// To understand the API, make sure you first understand the feature set
// listed above.
//
// Because the vertices are compact, they have very limited spatial
// precision. Thus a single mesh can only contain the data for a limited
// area. To make very large voxel maps, you'll need to build multiple
// vertex buffers. (But you want this anyway for frustum culling.)
//
// Each generated mesh has three components:
// - vertex data (vertex buffer)
// - face data (optional, stored in texture buffer)
// - mesh transform (uniforms)
//
// Once you've generated the mesh with this library, it's up to you
// to upload it to the GPU, to keep track of the state, and to render
// it.
//
// Concept
//
// The basic design is that you pass in one or more 3D arrays; each array
// is (typically) one-byte-per-voxel and contains information about one
// or more properties of the voxel particular property.
//
// Because there is so much per-vertex and per-face data possible
// in the output, and each voxel can have 6 faces and 8 faces, it
// would require an impossible large data structure to describe all
// of the possibilities. Instead, the API provides multiple ways
// to express each property; each such way has some limitations on
// what it can express. For the extreme case where you want to control
// every aspect manually, there is the option to pass in "sparse data",
// where you only pass in data for voxels that affect rendering (but
// in this case you could nearly build the mesh yourself).
//
//
// HISTORY:
//
// zmc engine 96-byte quads : 2011/10
// zmc engine 32-byte quads : 2013/12
// stb_voxel_render 20-byte quads: 2015/01
// stb_voxel_render 4..14 bytes : 2015/02???
// The following are candidate voxel modes. Only modes 0, 1, and 20 are
// currently implemented. Reducing the storage-per-quad further
// shouldn't improve performance, although obviously it allow you
// to create larger worlds without streaming.
//
//
// Mode: 0 1 2 3 4 5 6 10 11 12 20 21 22 23
// ============================================================================================================
// uses Tex Buffer n Y Y Y Y Y Y Y Y Y Y Y Y Y
// bytes per quad 32 20 14 12 10 6 6 8 6 4 20 10 6 4
// non-blocks all all some some some slabs stairs some some none all slabs slabs none
// tex1 256 256 256 256 256 256 256 256 256 256 n n n n
// tex2 256 256 256 256 256 256 128 n n n n n n n
// colors 64 64 64 64 64 64 64 8 n n 2^24 2^24 2^24 256
// vertex ao Y Y Y Y Y n n Y Y n Y Y n n
// face texblend Y Y Y Y n n n - - - - - - -
// vertex texlerp Y Y Y n n n n - - - - - - -
// x&y extents 127 127 128 64 64 128 64 64 128 128 64 64 128 128
// z extents 255 255 128 128 128 64 64 32 64 128 64 64 64 128
//
//
// With TexBuffer for the fixed vertex data, we can actually do
// minecrafty non-blocks like stairs -- we still probably only
// want 256 or so, so we can't do the equivalent of all the vheight
// combos, but that's ok. The 256 includes baked rotations, but only
// some of them need it, and lots of block types share some faces.
//
// mode 5 (6 bytes): mode 6 (6 bytes)
// x:7 x:6
// y:7 y:6
// z:6 z:6
// tex1:8 tex1:8
// tex2:8 tex2:7
// color:8 color:8
// face:4 face:7
//
//
// side faces (all x4) top&bottom faces (2x) internal faces (1x)
// 1 regular 1 regular
// 2 slabs 2
// 8 stairs 4 stairs 16
// 4 diag side 8
// 4 upper diag side 8
// 4 lower diag side 8
// 4 crossed pairs
//
// 23*4 + 5*4 + 46
// == 92 + 20 + 46 = 158
//
// Must drop 30 of them to fit in 7 bits:
// ceiling half diagonals: 16+8 = 24
// Need to get rid of 6 more.
// ceiling diagonals: 8+4 = 12
// This brings it to 122, so can add a crossed-pair variant.
// (diagonal and non-diagonal, or randomly offset)
// Or carpet, which would be 5 more.
//
//
// Mode 4 (10 bytes):
// v: z:2,light:6
// f: x:6,y:6,z:7, t1:8,t2:8,c:8,f:5
//
// Mode ? (10 bytes)
// v: xyz:5 (27 values), light:3
// f: x:7,y:7,z:6, t1:8,t2:8,c:8,f:4
// (v: x:2,y:2,z:2,light:2)
#ifndef INCLUDE_STB_VOXEL_RENDER_H
#define INCLUDE_STB_VOXEL_RENDER_H
#include <stdlib.h>
#ifdef STBVOX_BLOCKTYPE_SHORT
typedef unsigned short stbvox_block_type;
#else
typedef unsigned char stbvox_block_type;
#endif
// rendering API
enum
{
STBVOX_UNIFORM_face_data,
STBVOX_UNIFORM_transform,
STBVOX_UNIFORM_tex_array,
STBVOX_UNIFORM_texscale,
STBVOX_UNIFORM_color_table,
STBVOX_UNIFORM_normals,
STBVOX_UNIFORM_texgen,
STBVOX_UNIFORM_ambient,
STBVOX_UNIFORM_camera_pos,
STBVOX_UNIFORM__count,
};
enum
{
STBVOX_UNIFORM_TYPE_none,
STBVOX_UNIFORM_TYPE_sampler,
STBVOX_UNIFORM_TYPE_vec2,
STBVOX_UNIFORM_TYPE_vec3,
STBVOX_UNIFORM_TYPE_vec4,
};
typedef struct
{
int type;
int bytes_per_element;
int array_length;
char *name;
float *default_value; // if not NULL, you can use this as the uniform
unsigned int tags;
} stbvox_uniform_info;
typedef struct stbvox_mesh_maker stbvox_mesh_maker;
typedef struct stbvox_input_description stbvox_input_description;
extern stbvox_uniform_info *stbvox_get_uniform_info(stbvox_mesh_maker *mm, int uniform);
extern void stbvox_init_mesh_maker(stbvox_mesh_maker *mm);
extern int stbvox_make_mesh(stbvox_mesh_maker *mm);
extern int stbvox_get_buffer_count(stbvox_mesh_maker *mm);
extern int stbvox_get_buffer_size_per_quad(stbvox_mesh_maker *mm, int n);
extern void stbvox_reset_buffers(stbvox_mesh_maker *mm);
extern void stbvox_set_buffer(stbvox_mesh_maker *mm, int mesh, int slot, void *buffer, size_t len);
extern void stbvox_set_input_range(stbvox_mesh_maker *mm, int x0, int y0, int z0, int x1, int y1, int z1);
extern void stbvox_set_input_stride(stbvox_mesh_maker *mm, int x_stride_in_bytes, int y_stride_in_bytes);
extern void stbvox_config_use_gl(stbvox_mesh_maker *mm, int use_tex_buffer, int use_gl_modelview, int use_gl_fragment);
extern void stbvox_config_set_z_precision(stbvox_mesh_maker *mm, int z_fractional_bits);
extern stbvox_input_description *stbvox_get_input_description(stbvox_mesh_maker *mm);
extern int stbvox_get_vertex_shader(stbvox_mesh_maker *mm, char *buffer, size_t buffer_size);
extern int stbvox_get_fragment_shader(stbvox_mesh_maker *mm, char *buffer, size_t buffer_size);
extern void stbvox_set_default_mesh(stbvox_mesh_maker *mm, int mesh);
extern int stbvox_get_quad_count(stbvox_mesh_maker *mm, int mesh);
extern void stbvox_get_transform(stbvox_mesh_maker *mm, float transform[3][3]);
extern void stbvox_get_bounds(stbvox_mesh_maker *mm, float bounds[2][3]);
extern void stbvox_set_mesh_coordinates(stbvox_mesh_maker *mm, int x, int y, int z);
// meshing API
enum
{
STBVOX_GEOM_empty,
STBVOX_GEOM_knockout, // creates a hole in the mesh
STBVOX_GEOM_solid,
STBVOX_GEOM_transp, // solid geometry, but transparent contents so neighbors generate normally, unless same blocktype
// following 4 are redundant to vheight, but allowing them as well makes shared vheight more effective
STBVOX_GEOM_slab_upper,
STBVOX_GEOM_slab_lower,
STBVOX_GEOM_floor_slope_north_is_top,
STBVOX_GEOM_ceil_slope_north_is_bottom,
STBVOX_GEOM_floor_slope_north_is_top_as_wall_UNIMPLEMENTED, // same as floor_slope below, but uses wall's texture & texture projection
STBVOX_GEOM_ceil_slope_north_is_bottom_as_wall_UNIMPLEMENTED,
STBVOX_GEOM_crossed_pair, // corner-to-corner pairs, with normal vector bumped upwards
STBVOX_GEOM_force, // all faces always visible, e.g. minecraft fancy leaves
// these access vheight input
STBVOX_GEOM_floor_vheight_02 = 12, // diagonal is SW-NE -- assuming index buffer 0,1,2,0,2,3
STBVOX_GEOM_floor_vheight_13, // diagonal is SE-NW -- assuming index buffer 0,1,2,0,2,3
STBVOX_GEOM_ceil_vheight_02,
STBVOX_GEOM_ceil_vheight_13,
STBVOX_GEOM_count, // number of geom cases
};
// TODO: could possibly add stairs, fences, etc, but they don't obey
// the "1 quad per face" rule and they need more precision, so they'd
// have to be built very differently; so I don't plan on doing anything
// like that.
enum
{
STBVOX_VERTEX_HEIGHT_0,
STBVOX_VERTEX_HEIGHT_half,
STBVOX_VERTEX_HEIGHT_1,
};
enum
{
STBVOX_TEXLERP_0,
STBVOX_TEXLERP_half,
STBVOX_TEXLERP_1,
STBVOX_TEXLERP_use_vert,
};
enum
{
STBVOX_TEXLERP4_0_8,
STBVOX_TEXLERP4_1_8,
STBVOX_TEXLERP4_2_8,
STBVOX_TEXLERP4_3_8,
STBVOX_TEXLERP4_4_8,
STBVOX_TEXLERP4_5_8,
STBVOX_TEXLERP4_6_8,
STBVOX_TEXLERP4_7_8,
STBVOX_TEXLERP4_use_vert=15,
};
enum
{
STBVOX_FACE_east,
STBVOX_FACE_north,
STBVOX_FACE_west,
STBVOX_FACE_south,
STBVOX_FACE_up,
STBVOX_FACE_down,
};
#define STBVOX_BLOCKTYPE_EMPTY 0
#ifdef STBVOX_BLOCKTYPE_SHORT
#define STBVOX_BLOCKTYPE_HOLE 65535
#else
#define STBVOX_BLOCKTYPE_HOLE 255
#endif
#define STBVOX_MAKE_GEOMETRY(geom, rotate, vheight) ((geom) + (rotate)*16 + (vheight)*64)
#define STBVOX_MAKE_VHEIGHT(v_sw, v_se, v_nw, v_ne) ((v_sw) + (v_se)*4 + (v_nw)*16 + (v_ne)*64)
#define STBVOX_MAKE_MATROT(block, overlay, tex2, color) ((block) + (overlay)*4 + (tex2)*16 + (color)*64)
#define STBVOX_MAKE_TEX2_REPLACE(tex2, tex2_replace_face) ((tex2) + ((tex2_replace_face) & 3)*64)
#define STBVOX_MAKE_TEXLERP(ns2, ew2, ud2, vert) ((ew2) + (ns2)*4 + (ud2)*16 + (vert)*64)
#define STBVOX_MAKE_TEXLERP1(vert,e2,n2,w2,s2,u4,d2) STBVOX_MAKE_TEXLERP(s2, w2, d2, vert)
#define STBVOX_MAKE_TEXLERP2(vert,e2,n2,w2,s2,u4,d2) ((u2)*16 + (n2)*4 + (s2))
#define STBVOX_MAKE_FACE_MASK(e,n,w,s,u,d) ((e)+(n)*2+(w)*4+(s)*8+(u)*16+(d)*32)
#ifdef STBVOX_ROTATION_IN_LIGHTING
#define STBVOX_MAKE_LIGHTING(lighting, rot) (((lighting)&~3)+(rot))
#else
#define STBVOX_MAKE_LIGHTING(lighting) (lighting)
#endif
#ifndef STBVOX_MAX_MESHES
#define STBVOX_MAX_MESHES 2 // opaque & transparent
#endif
#define STBVOX_MAX_MESH_SLOTS 3 // one vertex & two faces, or two vertex and one face
struct stbvox_input_description
{
unsigned char lighting_at_vertices; // default is lighting values at block center
// these are 3D maps you use to define your voxel world, using x_stride and y_stride
// note that for cache efficiency, you want to use the block_foo palettes as much as possible instead
stbvox_block_type *blocktype; // index into palettes listed below
unsigned char *overlay; // index into palettes listed below
unsigned char *selector; // raw selector (chooses which mesh to write to)
unsigned char *geometry; // STBVOX_MAKE_GEOMETRY -- geom:4, rot:2, vheight:2
unsigned char *rotate; // STBVOX_MAKE_MATROT -- block:2, overlay:2, tex2:2, color:2
unsigned char *tex2; // raw tex2 value to use on all sides of block
unsigned char *tex2_replace; // STBVOX_MAKE_TEX2_REPLACE -- tex2:6, face_1:2
unsigned char *tex2_facemask; // facemask:6 (use all bits of tex2_replace as texture)
unsigned char *vheight; // STBVOX_MAKE_VHEIGHT -- sw:2, se:2, nw:2, ne:2, doesn't rotate
unsigned char *texlerp; // STBVOX_MAKE_TEXLERP -- vert:2, ud:2, ew:2, ns:2
unsigned char *texlerp2; // STBVOX_MAKE_TEXLERP2 (and use STBVOX_MAKE_TEXLERP1 for 'texlerp' -- e:2, n:2, u:3, unused:1
unsigned short *texlerp_vert3; // e:3,n:3,w:3,s:3,u:3 (down comes from 'texlerp')
unsigned short *texlerp_face3; // e:3,n:3,w:3,s:3,u:2,d:2
unsigned char *lighting; // lighting:8
unsigned char *color; // color for entire block
unsigned char *extended_color; // index into ecolor palettes
unsigned char *color2, *color2_facemask;// additional override colors with face bitmask
unsigned char *color3, *color3_facemask;// additional override colors with face bitmask
// indexed by tex1, used to determine tex2 if not otherwise specified
unsigned char *tex2_for_tex1; // 256
// @TODO: when specializing, build a single struct with all of the
// below values, so it's AoS instead of SoA for better cache efficiency
// these are "palettes" you use to define properties indexed by 'blocktype'
// indexed by blocktype*6+side
unsigned char (*block_tex1_face)[6];
unsigned char (*block_tex2_face)[6];
unsigned char (*block_color_face)[6];
unsigned char (*block_texlerp_face)[6];
// indexed by blocktype
unsigned char *block_geometry; // STBVOX_MAKE_GEOMETRY(geom,rot,0) -- use selector to encode independent rotation
unsigned char *block_vheight; // defines slopes and such; this vheight DOES get rotated
unsigned char *block_tex1;
unsigned char *block_tex2;
unsigned char *block_color;
unsigned char *block_texlerp;
unsigned char *block_selector;
// indexed by overlay*6+side; in all cases 0 means 'nochange'
unsigned char (*overlay_tex1)[6];
unsigned char (*overlay_tex2)[6];
unsigned char (*overlay_color)[6];
// indexed by extended_color
unsigned char *ecolor_color; // 256
unsigned char *ecolor_facemask; // 256
};
// don't mess with this directly, it's just here so you can
// declare stbvox_mesh_maker on the stack or as a global
struct stbvox_mesh_maker
{
stbvox_input_description input;
int cur_x, cur_y, cur_z; // last unprocessed voxel if it splits into multiple buffers
int x0,y0,z0,x1,y1,z1;
int x_stride_in_bytes;
int y_stride_in_bytes;
int precision_z;
int config_dirty;
int default_mesh;
unsigned int tags;
int cube_vertex_offset[6][4]; // this allows access per-vertex data stored block-centered (like texlerp, ambient)
int vertex_gather_offset[6][4];
int pos_x,pos_y,pos_z;
// computed from user input
char *output_cur [STBVOX_MAX_MESHES][STBVOX_MAX_MESH_SLOTS];
char *output_end [STBVOX_MAX_MESHES][STBVOX_MAX_MESH_SLOTS];
char *output_buffer[STBVOX_MAX_MESHES][STBVOX_MAX_MESH_SLOTS];
int output_len [STBVOX_MAX_MESHES][STBVOX_MAX_MESH_SLOTS];
// computed from config
int output_size [STBVOX_MAX_MESHES][STBVOX_MAX_MESH_SLOTS]; // per quad
int output_step [STBVOX_MAX_MESHES][STBVOX_MAX_MESH_SLOTS]; // per vertex or per face, depending
int num_mesh_slots;
float default_tex_scale[128][2];
};
#endif // INCLUDE_STB_VOXEL_RENDER_H
#ifdef STB_VOXEL_RENDER_IMPLEMENTATION
#include <stdlib.h>
#include <assert.h>
#include <string.h> // memset
#ifndef _MSC_VER
#include <stdint.h>
typedef uint16_t stbvox_uint16;
typedef uint32_t stbvox_uint32;
#else
typedef unsigned short stbvox_uint16;
typedef unsigned int stbvox_uint32;
#endif
// 20-byte quad format:
//
// per vertex:
//
// x:7
// y:7
// z:9
// ao:6
// tex_lerp:3
//
// per face:
//
// tex1:8
// tex2:8
// face:8
// color:8
// Default uniform values
static float stbvox_default_texgen[2][16][3] =
{
{ { 0,1,0 }, { 1,0,0 }, { 0,-1,0 }, { -1,0,0 }, { 1,0,0 }, { -1,0,0 } },
{ { 0,0,-1 }, { 0,0,-1 }, { 0,0,-1 }, { 0,0,-1 }, { 0,-1,0 }, { 0,1,0 } },
};
static float stbvox_default_normals[32][3] =
{
{ 1,0,0 }, { 0,1,0 }, { -1,0,0 }, { 0,-1,0 }, { 0,0,1 }, { 0,0,-1 }
};
static float stbvox_default_texscale[128][2] =
{
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
};
static unsigned char stbvox_default_palette_compact[64][3] =
{
{ 255,255,255 }, { 238,238,238 }, { 221,221,221 }, { 204,204,204 },
{ 187,187,187 }, { 170,170,170 }, { 153,153,153 }, { 136,136,136 },
{ 119,119,119 }, { 102,102,102 }, { 85, 85, 85 }, { 68, 68, 68 },
{ 51, 51, 51 }, { 34, 34, 34 }, { 17, 17, 17 }, { 0, 0, 0 },
{ 255,240,240 }, { 255,220,220 }, { 255,160,160 }, { 255, 32, 32 },
{ 200,120,160 }, { 200, 60,150 }, { 220,100,130 }, { 255, 0,128 },
{ 240,240,255 }, { 220,220,255 }, { 160,160,255 }, { 32, 32,255 },
{ 120,160,200 }, { 60,150,200 }, { 100,130,220 }, { 0,128,255 },
{ 240,255,240 }, { 220,255,220 }, { 160,255,160 }, { 32,255, 32 },
{ 160,200,120 }, { 150,200, 60 }, { 130,220,100 }, { 128,255, 0 },
{ 255,255,240 }, { 255,255,220 }, { 220,220,180 }, { 255,255, 32 },
{ 200,160,120 }, { 200,150, 60 }, { 220,130,100 }, { 255,128, 0 },
{ 255,240,255 }, { 255,220,255 }, { 220,180,220 }, { 255, 32,255 },
{ 160,120,200 }, { 150, 60,200 }, { 130,100,220 }, { 128, 0,255 },
{ 240,255,255 }, { 220,255,255 }, { 180,220,220 }, { 32,255,255 },
{ 120,200,160 }, { 60,200,150 }, { 100,220,130 }, { 0,255,128 },
};
static float stbvox_default_palette[64][4];
void stbvox_build_default_palette(void)
{
int i;
for (i=0; i < 64; ++i) {
stbvox_default_palette[i][0] = stbvox_default_palette_compact[i][0] / 255.0f;
stbvox_default_palette[i][1] = stbvox_default_palette_compact[i][1] / 255.0f;
stbvox_default_palette[i][2] = stbvox_default_palette_compact[i][2] / 255.0f;
stbvox_default_palette[i][3] = 0.0f;
}
}
// Shaders
#define STBVOX_TAG_all (1 << 0)
#define STBVOX_TAG_gl (1 << 1)
#define STBVOX_TAG_d3d (1 << 2)
#define STBVOX_TAG_glsl_130 (1 << 3)
#define STBVOX_TAG_glsl_150 (1 << 4)
#define STBVOX_TAG_glsl_150_compatibility (1 << 5)
#define STBVOX_TAG_face_sampled (1 << 6)
#define STBVOX_TAG_face_attribute (1 << 7)
#define STBVOX_TAG_gl_modelview (1 << 8)
#define STBVOX_TAG_textured (1 << 10)
#define STBVOX_TAG_NOT (1 << 31)
typedef struct
{
unsigned int tag;
char *str;
} stbvox_tagged_string;
stbvox_tagged_string stbvox_vertex_program[] =
{
{ STBVOX_TAG_glsl_130,
"#version 130\n"
},
{ STBVOX_TAG_glsl_150,
"#version 150\n"
},
{ STBVOX_TAG_glsl_150_compatibility,
"#version 150 compatibility\n"
},
{ STBVOX_TAG_face_sampled,
"uniform usamplerBuffer facearray;\n"
},
{ STBVOX_TAG_face_attribute,
"in uvec4 attr_face;\n"
},
{ STBVOX_TAG_all,
// vertex input data
"in uint attr_vertex;\n"
// per-buffer data
"uniform vec3 transform[3];\n"
// to simplify things, we avoid using more than 256 uniform vectors
// in fragment shader to avoid possible 1024 component limit, so
// we access this table in the fragment shader.
"uniform vec3 normal_table[32];\n"
// fragment output data
"flat out uvec4 facedata;\n"
" out vec3 objectspace_pos;\n"
" out vec3 vnormal;\n"
" out float texlerp;\n"
" out float amb_occ;\n"
},
{ STBVOX_TAG_NOT | STBVOX_TAG_gl_modelview,
"uniform mat44 model_view;\n"
},
{ STBVOX_TAG_all,
// @TODO handle the HLSL way to do this
"void main()\n"
"{\n"
},
{ STBVOX_TAG_face_attribute,
" facedata = attr_face;\n"
},
{ STBVOX_TAG_face_sampled,
" int faceID = gl_VertexID >> 2;\n"
" facedata = texelFetch(facearray, faceID);\n"
},
{ STBVOX_TAG_all,
// extract data for vertex
" vec3 offset;\n"
" offset.x = float( (attr_vertex ) & 127u );\n" // a[0..6]
" offset.y = float( (attr_vertex >> 7u) & 127u );\n" // a[7..13]
" offset.z = float( (attr_vertex >> 14u) & 511u );\n" // a[14..22]
" amb_occ = float( (attr_vertex >> 23u) & 63u ) / 63.0;\n" // a[23..28]
" texlerp = float( (attr_vertex >> 29u) ) / 7.0;\n" // a[29..31]
" vnormal = normal_table[facedata.w & 31u];\n"
" objectspace_pos = offset * transform[0];\n" // object-to-world scale
" vec3 position = objectspace_pos + transform[1];\n" // object-to-world translate
},
{ STBVOX_TAG_NOT | STBVOX_TAG_gl_modelview,
" gl_Position = model_view * vec4(position,1.0);\n"
"}"
},
{ STBVOX_TAG_gl_modelview,
" gl_Position = gl_ModelViewProjectionMatrix * vec4(position,1.0);\n"
"}"
},
};
stbvox_tagged_string stbvox_fragment_program[] =
{
{ STBVOX_TAG_glsl_130,
"#version 130\n"
},
{ STBVOX_TAG_glsl_150,
"#version 150\n"
},
{ STBVOX_TAG_glsl_150_compatibility,
"#version 150 compatibility\n"
},
{ STBVOX_TAG_all,
// rlerp is lerp but with t on the left, like god intended
"#define rlerp(t,x,y) mix(x,y,t)\n"
// fragment output data
"flat in uvec4 facedata;\n"
" in vec3 objectspace_pos;\n"
" in vec3 vnormal;\n"
" in float texlerp;\n"
" in float amb_occ;\n"
// per-buffer data
"uniform vec3 transform[3];\n"
// per-frame data
"uniform vec3 camera_pos;\n"
// probably constant data
"uniform vec3 ambient[4];\n"
},
{ STBVOX_TAG_textured,
// generally constant data
"uniform sampler2DArray tex_array[2];\n"
#if 0
"uniform vec4 color_table[64];\n"
"uniform vec2 texscale[128];\n"
"uniform vec3 texgen[32];\n"
#else
"uniform samplerBuffer color_table;\n"
"uniform samplerBuffer texscale;\n"
"uniform samplerBuffer texgen;\n"
#endif
},
{ STBVOX_TAG_all,
"out vec4 outcolor;\n"
},
{ STBVOX_TAG_all,
"void main()\n"
"{\n"
" vec3 albedo;\n"
" float fragment_alpha;\n"
},
{ STBVOX_TAG_textured,
// unpack the values
" uint tex1_id = facedata.x;\n"
" uint tex2_id = facedata.y;\n"
" uint texprojid = facedata.w & 15u;\n"
" uint color_id = facedata.z;\n"
" bool texblend_mode = ((facedata.w & 128u) != 0u);\n"
#if 0
// load from uniforms / texture buffers
" vec3 texgen_s = texgen[texprojid];\n"
" vec3 texgen_t = texgen[texprojid+16u];\n"
" float tex1_scale = texscale[tex1_id & 127u].x;\n"
" float tex2_scale = texscale[tex2_id & 127u].y;\n"
" vec4 color = color_table[color_id & 63u];\n"
#else
" vec3 texgen_s = texelFetch(texgen, int(texprojid)).xyz;\n"
" vec3 texgen_t = texelFetch(texgen, int(texprojid+16u)).xyz;\n"
" float tex1_scale = texelFetch(texscale, int(tex1_id & 127u)).x;\n"
" float tex2_scale = texelFetch(texscale, int(tex2_id & 127u)).y;\n"
" vec4 color = texelFetch(color_table, int(color_id & 63u));\n"
#endif
" vec2 texcoord;\n"
" vec3 texturespace_pos = objectspace_pos + transform[2].xyz;\n"
" texcoord.s = dot(texturespace_pos, texgen_s);\n"
" texcoord.t = dot(texturespace_pos, texgen_t);\n"
// @TODO: use 2 bits of facedata.w to enable animation of facedata.x & y
" vec4 tex1 = texture(tex_array[0], vec3(tex1_scale * texcoord, float(tex1_id)));\n"
" vec4 tex2 = texture(tex_array[1], vec3(tex2_scale * texcoord, float(tex2_id)));\n"
" bool emissive = (int(color.w) & 1) != 0;\n"
// recolor textures
" if ((color_id & 64u) != 0u) tex1.xyz *= color.xyz;\n"
" if ((color_id & 128u) != 0u) tex2.xyz *= color.xyz;\n"
" tex2.a *= texlerp;\n"
// @TODO: could use a separate lookup table keyed on tex2 to determine this
" if (texblend_mode)\n"
" albedo = tex2.xyz * rlerp(tex2.a, 2.0*tex1.xyz, vec3(1.0,1.0,1.0));\n"
" else\n"
" albedo = rlerp(tex2.a, tex1.xyz, tex2.xyz);\n" // @TODO premultiplied alpha
" fragment_alpha = tex1.a;\n"
},
{ STBVOX_TAG_NOT | STBVOX_TAG_textured,
" vec4 color;"
" color.xyz = vec3(facedata.xyz) / 255.0;\n"
" bool emissive = (facedata.w & 128) != 0;\n"
" albedo = color.xyz;\n"
" fragment_alpha = 1.0;\n"
},
{ STBVOX_TAG_all,
// compute the normal
" vec3 normal = vnormal;\n"
//" vec3 normal = normalize(vnormal);\n"
// @TODO: bump map normal
" vec3 amb_color = dot(normal, ambient[0]) * ambient[1] + ambient[2];\n"
" amb_color = clamp(amb_color, 0.0, 1.0);"
" amb_color *= amb_occ;\n"
" vec3 lit_color;\n"
" if (!emissive)\n"
" lit_color = amb_color * albedo;\n"
" else\n"
" lit_color = albedo;\n"
// @TODO dynamic lighting based on normal, and based on "vec3 worldspace_pos = objectspace_pos + o2w[1];\n"
// @TODO shadow test
// @TODO fog
// smoothstep fog:
#if 1
" vec3 dist = objectspace_pos + (transform[1] - camera_pos);\n"
" float f = sqrt(dot(dist,dist))/1320.0;\n"
" f = clamp(f, 0.0, 1.0);\n"
" f = 3.0*f*f - 2.0*f*f*f;\n" // smoothstep
" f = f*f;\n" // fade in more smoothly
" lit_color.xyz = rlerp(f, lit_color.xyz, ambient[3]);\n"
#endif
" vec4 final_color = vec4(lit_color, fragment_alpha);\n"
" outcolor = final_color;\n"
"}"
},
};
static int stbvox_check_tag(stbvox_mesh_maker *mm, unsigned int test_tag)
{
if (test_tag & STBVOX_TAG_NOT)
return (test_tag & mm->tags) == 0; // require absence of all tags
else
return (test_tag & mm->tags) == test_tag; // require AND of all tags
}
static int stbvox_build_tagged_string(stbvox_mesh_maker *mm, char *buffer, size_t buffer_size, stbvox_tagged_string *str, int num_chunks)
{
size_t pos=0;
int i;
for (i=0; i < num_chunks; ++i) {
if (stbvox_check_tag(mm, str[i].tag)) {
char *text = str[i].str;
while (*text) {
if (pos < buffer_size)
buffer[pos] = *text;
++pos;
++text;
}
}
}
if (pos < buffer_size) {
buffer[pos++] = 0;
return pos;
} else {
return -(int)pos;
}
}
int stbvox_get_vertex_shader(stbvox_mesh_maker *mm, char *buffer, size_t buffer_size)
{
return stbvox_build_tagged_string(mm, buffer, buffer_size,
stbvox_vertex_program,
sizeof(stbvox_vertex_program)/sizeof(stbvox_vertex_program[0]));
}
int stbvox_get_fragment_shader(stbvox_mesh_maker *mm, char *buffer, size_t buffer_size)
{
return stbvox_build_tagged_string(mm, buffer, buffer_size,
stbvox_fragment_program,
sizeof(stbvox_fragment_program)/sizeof(stbvox_fragment_program[0]));
}
static float stbvox_dummy_transform[3][3];
stbvox_uniform_info stbvox_uniforms[] =
{
{ STBVOX_UNIFORM_TYPE_sampler , 4, 1, "facearray" , 0 , STBVOX_TAG_face_sampled },
{ STBVOX_UNIFORM_TYPE_vec3 , 12, 3, "transform" , stbvox_dummy_transform[0] , STBVOX_TAG_all },
{ STBVOX_UNIFORM_TYPE_sampler , 4, 2, "tex_array" , 0 , STBVOX_TAG_textured },
{ STBVOX_UNIFORM_TYPE_vec2 , 8, 128, "texscale" , stbvox_default_texscale[0] , STBVOX_TAG_textured },
{ STBVOX_UNIFORM_TYPE_vec4 , 16, 64, "color_table" , stbvox_default_palette[0] , STBVOX_TAG_textured },
{ STBVOX_UNIFORM_TYPE_vec3 , 12, 32, "normal_table" , stbvox_default_normals[0] , STBVOX_TAG_all },
{ STBVOX_UNIFORM_TYPE_vec3 , 12, 32, "texgen" , stbvox_default_texgen[0][0] , STBVOX_TAG_textured },
{ STBVOX_UNIFORM_TYPE_vec3 , 12, 4, "ambient" , 0 , STBVOX_TAG_all },
{ STBVOX_UNIFORM_TYPE_vec3 , 12, 1, "camera_pos" , stbvox_dummy_transform[0] , STBVOX_TAG_all },
};
stbvox_uniform_info *stbvox_get_uniform_info(stbvox_mesh_maker *mm, int uniform)
{
if (stbvox_default_palette[0][0] == 0) // NOTE: not threadsafe, so call once to init
stbvox_build_default_palette();
if (uniform < 0 || uniform >= STBVOX_UNIFORM__count)
return NULL;
if (stbvox_check_tag(mm, stbvox_uniforms[uniform].tags))
return &stbvox_uniforms[uniform];
else
return NULL;
}
#define STBVOX_GET_GEO(geom_data) ((geom_data) & 15)
typedef stbvox_uint32 stbvox_mesh_vertex;
typedef struct
{
unsigned char tex1,tex2,color,face_info;
} stbvox_mesh_face;
#define stbvox_vertex_p(x,y,z,ao,texlerp) ((stbvox_uint32) ((x)+((y)<<7)+((z)<<14)+((ao)<<23)+((texlerp)<<29)))
typedef struct
{
unsigned char block;
unsigned char overlay;
unsigned char tex2;
unsigned char ecolor;
} stbvox_rotate;
typedef struct
{
unsigned char x,y,z;
} stbvox_pos;
static unsigned char stbvox_rotate_face[6][4] =
{
{ 0,1,2,3 },
{ 1,2,3,0 },
{ 2,3,0,1 },
{ 3,0,1,2 },
{ 4,4,4,4 },
{ 5,5,5,5 },
};
#define STBVOX_ROTATE(x,r) stbvox_rotate_face[x][r] // (((x)+(r))&3)
static unsigned char face_info_for_side[6] =
{
0,1,2,3,4,5
};
stbvox_mesh_face stbvox_compute_mesh_face_value(stbvox_mesh_maker *mm, stbvox_rotate rot, int face, int v_off)
{
unsigned char color_face;
stbvox_mesh_face face_data = { 0 };
stbvox_block_type bt = mm->input.blocktype[v_off];
unsigned char bt_face = STBVOX_ROTATE(face, rot.block);
if (mm->input.color)
face_data.color = mm->input.color[v_off];
if (mm->input.block_tex1)
face_data.tex1 = mm->input.block_tex1[bt];
else if (mm->input.block_tex1_face)
face_data.tex1 = mm->input.block_tex1_face[bt][bt_face];
else
face_data.tex1 = bt;
if (mm->input.block_tex2)
face_data.tex2 = mm->input.block_tex2[bt];
else if (mm->input.block_tex2_face)
face_data.tex2 = mm->input.block_tex2_face[bt][bt_face];
if (mm->input.block_color) {
unsigned char mcol = mm->input.block_color[bt];
if (mcol)
face_data.color = mcol;
} else if (mm->input.block_color_face) {
unsigned char mcol = mm->input.block_color_face[bt][bt_face];
if (mcol)
face_data.color = mcol;
}
if (mm->input.overlay) {
int over_face = STBVOX_ROTATE(face, rot.overlay);
unsigned char over = mm->input.overlay[v_off];
if (mm->input.overlay_tex1) {
unsigned char rep1 = mm->input.overlay_tex1[over][over_face];
if (rep1)
face_data.tex1 = rep1;
}
if (mm->input.overlay_tex2) {
unsigned char rep2 = mm->input.overlay_tex1[over][over_face];
if (rep2)
face_data.tex2 = rep2;
}
if (mm->input.overlay_color) {
unsigned char rep3 = mm->input.overlay_color[over][over_face];
if (rep3)
face_data.color = rep3;
}
}
if (mm->input.tex2_for_tex1)
face_data.tex2 = mm->input.tex2_for_tex1[face_data.tex1];
if (mm->input.tex2)
face_data.tex2 = mm->input.tex2[v_off];
if (mm->input.tex2_replace) {
int tex2_face = STBVOX_ROTATE(face, rot.tex2);
if (mm->input.tex2_facemask[v_off] & (1 << tex2_face))
face_data.tex2 = mm->input.tex2_replace[v_off];
}
color_face = STBVOX_ROTATE(face, rot.ecolor);
if (mm->input.extended_color) {
unsigned char ec = mm->input.extended_color[v_off];
if (mm->input.ecolor_facemask[ec] & (1 << color_face))
face_data.color = mm->input.ecolor_color[ec];
}
if (mm->input.color2) {
if (mm->input.color2_facemask[v_off] & (1 << color_face))
face_data.color = mm->input.color2[v_off];
if (mm->input.color3 && (mm->input.color3_facemask[v_off] & (1 << color_face)))
face_data.color = mm->input.color3[v_off];
}
face_data.face_info = face_info_for_side[face];
return face_data;
}
static unsigned char stbvox_face_lerp[6] = { 0,2,0,2,4,4 };
static unsigned char stbvox_vert3_lerp[6] = { 0,3,6,9,12,12 };
static unsigned char stbvox_vert_lerp_for_face_lerp[6] = { 0, 4, 7 };
static unsigned char stbvox_face3_lerp[6] = { 0,3,6,9,12,14 };
static unsigned char stbvox_face3_updown[8] = { 0,2,4,7,0,2,4,7 };
// vertex offsets for face vertices
static unsigned char stbvox_vertex_vector[6][4][3] =
{
{ { 1,0,1 }, { 1,1,1 }, { 1,1,0 }, { 1,0,0 } }, // east
{ { 1,1,1 }, { 0,1,1 }, { 0,1,0 }, { 1,1,0 } }, // north
{ { 0,1,1 }, { 0,0,1 }, { 0,0,0 }, { 0,1,0 } }, // west
{ { 0,0,1 }, { 1,0,1 }, { 1,0,0 }, { 0,0,0 } }, // south
{ { 0,1,1 }, { 1,1,1 }, { 1,0,1 }, { 0,0,1 } }, // up
{ { 0,0,0 }, { 1,0,0 }, { 1,1,0 }, { 0,1,0 } }, // down
};
// stbvox_vertex_vector, but read coordinates as binary numbers, zyx
static unsigned char stbvox_vertex_selector[6][4] =
{
{ 5,7,3,1 },
{ 7,6,2,3 },
{ 6,4,0,2 },
{ 4,5,1,0 },
{ 6,7,5,4 },
{ 0,1,3,2 },
};
static stbvox_mesh_vertex stbvox_vmesh_delta_normal[6][4] =
{
{ stbvox_vertex_p(1,0,1,0,0) ,
stbvox_vertex_p(1,1,1,0,0) ,
stbvox_vertex_p(1,1,0,0,0) ,
stbvox_vertex_p(1,0,0,0,0) },
{ stbvox_vertex_p(1,1,1,0,0) ,
stbvox_vertex_p(0,1,1,0,0) ,
stbvox_vertex_p(0,1,0,0,0) ,
stbvox_vertex_p(1,1,0,0,0) },
{ stbvox_vertex_p(0,1,1,0,0) ,
stbvox_vertex_p(0,0,1,0,0) ,
stbvox_vertex_p(0,0,0,0,0) ,
stbvox_vertex_p(0,1,0,0,0) },
{ stbvox_vertex_p(0,0,1,0,0) ,
stbvox_vertex_p(1,0,1,0,0) ,
stbvox_vertex_p(1,0,0,0,0) ,
stbvox_vertex_p(0,0,0,0,0) },
{ stbvox_vertex_p(0,1,1,0,0) ,
stbvox_vertex_p(1,1,1,0,0) ,
stbvox_vertex_p(1,0,1,0,0) ,
stbvox_vertex_p(0,0,1,0,0) },
{ stbvox_vertex_p(0,0,0,0,0) ,
stbvox_vertex_p(1,0,0,0,0) ,
stbvox_vertex_p(1,1,0,0,0) ,
stbvox_vertex_p(0,1,0,0,0) }
};
static stbvox_mesh_vertex stbvox_vmesh_pre_vheight[6][4] =
{
{ stbvox_vertex_p(1,0,0,0,0) ,
stbvox_vertex_p(1,1,0,0,0) ,
stbvox_vertex_p(1,1,0,0,0) ,
stbvox_vertex_p(1,0,0,0,0) },
{ stbvox_vertex_p(1,1,0,0,0) ,
stbvox_vertex_p(0,1,0,0,0) ,
stbvox_vertex_p(0,1,0,0,0) ,
stbvox_vertex_p(1,1,0,0,0) },
{ stbvox_vertex_p(0,1,0,0,0) ,
stbvox_vertex_p(0,0,0,0,0) ,
stbvox_vertex_p(0,0,0,0,0) ,
stbvox_vertex_p(0,1,0,0,0) },
{ stbvox_vertex_p(0,0,0,0,0) ,
stbvox_vertex_p(1,0,0,0,0) ,
stbvox_vertex_p(1,0,0,0,0) ,
stbvox_vertex_p(0,0,0,0,0) },
{ stbvox_vertex_p(0,1,0,0,0) ,
stbvox_vertex_p(1,1,0,0,0) ,
stbvox_vertex_p(1,0,0,0,0) ,
stbvox_vertex_p(0,0,0,0,0) },
{ stbvox_vertex_p(0,0,0,0,0) ,
stbvox_vertex_p(1,0,0,0,0) ,
stbvox_vertex_p(1,1,0,0,0) ,
stbvox_vertex_p(0,1,0,0,0) }
};
static stbvox_mesh_vertex stbvox_vmesh_delta_half_z[6][4] =
{
{ stbvox_vertex_p(1,0,2,0,0) ,
stbvox_vertex_p(1,1,2,0,0) ,
stbvox_vertex_p(1,1,0,0,0) ,
stbvox_vertex_p(1,0,0,0,0) },
{ stbvox_vertex_p(1,1,2,0,0) ,
stbvox_vertex_p(0,1,2,0,0) ,
stbvox_vertex_p(0,1,0,0,0) ,
stbvox_vertex_p(1,1,0,0,0) },
{ stbvox_vertex_p(0,1,2,0,0) ,
stbvox_vertex_p(0,0,2,0,0) ,
stbvox_vertex_p(0,0,0,0,0) ,
stbvox_vertex_p(0,1,0,0,0) },
{ stbvox_vertex_p(0,0,2,0,0) ,
stbvox_vertex_p(1,0,2,0,0) ,
stbvox_vertex_p(1,0,0,0,0) ,
stbvox_vertex_p(0,0,0,0,0) },
{ stbvox_vertex_p(0,1,2,0,0) ,
stbvox_vertex_p(1,1,2,0,0) ,
stbvox_vertex_p(1,0,2,0,0) ,
stbvox_vertex_p(0,0,2,0,0) },
{ stbvox_vertex_p(0,0,0,0,0) ,
stbvox_vertex_p(1,0,0,0,0) ,
stbvox_vertex_p(1,1,0,0,0) ,
stbvox_vertex_p(0,1,0,0,0) }
};
static stbvox_mesh_vertex stbvox_vmesh_crossed_pair[6][4] =
{
{ stbvox_vertex_p(1,0,2,0,0) ,
stbvox_vertex_p(0,1,2,0,0) ,
stbvox_vertex_p(0,1,0,0,0) ,
stbvox_vertex_p(1,0,0,0,0) },
{ stbvox_vertex_p(1,1,2,0,0) ,
stbvox_vertex_p(0,0,2,0,0) ,
stbvox_vertex_p(0,0,0,0,0) ,
stbvox_vertex_p(1,1,0,0,0) },
{ stbvox_vertex_p(0,1,2,0,0) ,
stbvox_vertex_p(1,0,2,0,0) ,
stbvox_vertex_p(1,0,0,0,0) ,
stbvox_vertex_p(0,1,0,0,0) },
{ stbvox_vertex_p(0,0,2,0,0) ,
stbvox_vertex_p(1,1,2,0,0) ,
stbvox_vertex_p(1,1,0,0,0) ,
stbvox_vertex_p(0,0,0,0,0) },
// not used, so we leave it non-degenerate to make sure it doesn't get gen'd accidentally
{ stbvox_vertex_p(0,1,2,0,0) ,
stbvox_vertex_p(1,1,2,0,0) ,
stbvox_vertex_p(1,0,2,0,0) ,
stbvox_vertex_p(0,0,2,0,0) },
{ stbvox_vertex_p(0,0,0,0,0) ,
stbvox_vertex_p(1,0,0,0,0) ,
stbvox_vertex_p(1,1,0,0,0) ,
stbvox_vertex_p(0,1,0,0,0) }
};
void stbvox_get_quad_vertex_pointer(stbvox_mesh_maker *mm, int mesh, stbvox_mesh_vertex **vertices, stbvox_mesh_face face)
{
char *p = mm->output_cur[mesh][0];
int step = mm->output_step[mesh][0];
// allocate a new quad from the mesh
vertices[0] = (stbvox_mesh_vertex *) p; p += step;
vertices[1] = (stbvox_mesh_vertex *) p; p += step;
vertices[2] = (stbvox_mesh_vertex *) p; p += step;
vertices[3] = (stbvox_mesh_vertex *) p; p += step;
mm->output_cur[mesh][0] = p;
// output the face
if (mm->tags & STBVOX_TAG_face_attribute) {
*(stbvox_mesh_face *) (vertices[0]+1) = face;
*(stbvox_mesh_face *) (vertices[1]+1) = face;
*(stbvox_mesh_face *) (vertices[2]+1) = face;
*(stbvox_mesh_face *) (vertices[3]+1) = face;
} else {
*(stbvox_mesh_face *) mm->output_cur[mesh][1] = face;
mm->output_cur[mesh][1] += 4;
}
}
void stbvox_make_mesh_for_face(stbvox_mesh_maker *mm, stbvox_rotate rot, int face, int v_off, stbvox_pos pos, stbvox_mesh_vertex vertbase, stbvox_mesh_vertex *face_coord, unsigned char mesh)
{
stbvox_mesh_face face_data = stbvox_compute_mesh_face_value(mm,rot,face,v_off);
// still need to compute ao & texlerp for each vertex
// first compute texlerp into p1
stbvox_mesh_vertex p1[4] = { 0 };
if (mm->input.block_texlerp) {
stbvox_block_type bt = mm->input.blocktype[v_off];
unsigned char val = mm->input.block_texlerp[bt];
p1[0] = p1[1] = p1[2] = p1[3] = stbvox_vertex_p(0,0,0,0,val);
} else if (mm->input.block_texlerp_face) {
stbvox_block_type bt = mm->input.blocktype[v_off];
unsigned char bt_face = STBVOX_ROTATE(face, rot.block);
unsigned char val = mm->input.block_texlerp_face[bt][bt_face];
p1[0] = p1[1] = p1[2] = p1[3] = stbvox_vertex_p(0,0,0,0,val);
} else if (mm->input.texlerp_face3) {
unsigned char val = (mm->input.texlerp_face3[v_off] >> stbvox_face3_lerp[face]) & 7;
if (face >= 4)
val = stbvox_face3_updown[val];
p1[0] = p1[1] = p1[2] = p1[3] = stbvox_vertex_p(0,0,0,0,val);
} else if (mm->input.texlerp) {
unsigned char facelerp = (mm->input.texlerp[v_off] >> stbvox_face_lerp[face]) & 3;
if (facelerp == STBVOX_TEXLERP_use_vert) {
if (mm->input.texlerp_vert3 && face != STBVOX_FACE_down) {
unsigned char shift = stbvox_vert3_lerp[face];
p1[0] = (mm->input.texlerp_vert3[mm->cube_vertex_offset[face][0]] >> shift) & 7;
p1[1] = (mm->input.texlerp_vert3[mm->cube_vertex_offset[face][1]] >> shift) & 7;
p1[2] = (mm->input.texlerp_vert3[mm->cube_vertex_offset[face][2]] >> shift) & 7;
p1[3] = (mm->input.texlerp_vert3[mm->cube_vertex_offset[face][3]] >> shift) & 7;
} else {
p1[0] = stbvox_vert_lerp_for_face_lerp[mm->input.texlerp[mm->cube_vertex_offset[face][0]]>>6];
p1[1] = stbvox_vert_lerp_for_face_lerp[mm->input.texlerp[mm->cube_vertex_offset[face][1]]>>6];
p1[2] = stbvox_vert_lerp_for_face_lerp[mm->input.texlerp[mm->cube_vertex_offset[face][2]]>>6];
p1[3] = stbvox_vert_lerp_for_face_lerp[mm->input.texlerp[mm->cube_vertex_offset[face][3]]>>6];
}
p1[0] = stbvox_vertex_p(0,0,0,0,p1[0]);
p1[1] = stbvox_vertex_p(0,0,0,0,p1[1]);
p1[2] = stbvox_vertex_p(0,0,0,0,p1[2]);
p1[3] = stbvox_vertex_p(0,0,0,0,p1[3]);
} else {
p1[0] = p1[1] = p1[2] = p1[3] = stbvox_vertex_p(0,0,0,0,stbvox_vert_lerp_for_face_lerp[facelerp]);
}
} else {
p1[0] = p1[1] = p1[2] = p1[3] = stbvox_vertex_p(0,0,0,0,7);
}
{
stbvox_mesh_vertex *mv[4];
stbvox_get_quad_vertex_pointer(mm, mesh, mv, face_data);
if (mm->input.lighting) {
if (mm->input.lighting_at_vertices) {
int i;
for (i=0; i < 4; ++i) {
*mv[i] = vertbase + face_coord[i];
+ stbvox_vertex_p(0,0,0,mm->input.lighting[v_off + mm->cube_vertex_offset[face][i]] & 63,0);
}
} else {
unsigned char *amb = &mm->input.lighting[v_off];
int i,j;
#ifdef STBVOX_ROTATION_IN_LIGHTING
#define STBVOX_GET_LIGHTING(light) ((light) & ~3)
#define STBVOX_LIGHTING_ROUNDOFF 8
#else
#define STBVOX_GET_LIGHTING(light) (light)
#define STBVOX_LIGHTING_ROUNDOFF 2
#endif
for (i=0; i < 4; ++i) {
// for each vertex, gather from the four neighbor blocks it's facing
unsigned char *vamb = &amb[mm->cube_vertex_offset[face][i]];
int total=0;
for (j=0; j < 4; ++j)
total += STBVOX_GET_LIGHTING(vamb[mm->vertex_gather_offset[face][j]]);
*mv[i] = vertbase + face_coord[i]
+ stbvox_vertex_p(0,0,0,(total+STBVOX_LIGHTING_ROUNDOFF)>>4,0);
// >> 4 is because:
// >> 2 to divide by 4 to get average over 4 samples
// >> 2 because input is 8 bits, output is 6 bits
}
// @TODO: gather baked lighting where we have precomputed
// shadow bits for each light and we gather them from neighbors
// as above then do normal diffuse light computation--this
// needs a variant shader which has 8-bit rgb as well, in
// which case 'lighting' isn't needed so we have ~14 more
// bits to store stuff per vertex
//
// Or alternatively note that gathering baked *lighting*
// is different from gathering baked ao; baked ao can count
// solid blocks as 0 ao, but baked lighting wants average
// of non-blocked, not average & treat blocked as 0. And
// we can't bake the right value into the solid blocks
// because they can have different lighting values on
// different sides.
}
} else {
int i;
for (i=0; i < 4; ++i) {
*mv[i] = vertbase + face_coord[i] + p1[i];
}
}
}
}
// simple case for mesh generation: we have only solid and empty blocks
void stbvox_make_mesh_for_block(stbvox_mesh_maker *mm, stbvox_pos pos, int v_off, stbvox_mesh_vertex *vmesh)
{
int ns_off = mm->y_stride_in_bytes;
int ew_off = mm->x_stride_in_bytes;
unsigned char *blockptr = &mm->input.blocktype[v_off];
stbvox_mesh_vertex basevert = stbvox_vertex_p(pos.x, pos.y, pos.z<<mm->precision_z , 0,0);
stbvox_rotate rot = { 0,0,0,0 };
unsigned char simple_rot = 0;
unsigned char mesh = mm->default_mesh;
if (mm->input.selector) {
mesh = mm->input.selector[v_off];
simple_rot = mesh >> 4;
mesh &= 15;
}
// check if we're going off the end
if (mm->output_cur[mesh][0] + mm->output_size[mesh][0]*6 > mm->output_end[mesh][0]) {
assert(0);
return;
}
if (blockptr[ 1]==0)
stbvox_make_mesh_for_face(mm, rot, STBVOX_FACE_up , v_off, pos, basevert, vmesh+4*STBVOX_FACE_up, mesh);
if (blockptr[-1]==0)
stbvox_make_mesh_for_face(mm, rot, STBVOX_FACE_down, v_off, pos, basevert, vmesh+4*STBVOX_FACE_down, mesh);
if (mm->input.rotate) {
unsigned char val = mm->input.rotate[v_off];
rot.block = (val >> 0) & 3;
rot.overlay = (val >> 2) & 3;
rot.tex2 = (val >> 4) & 3;
rot.ecolor = (val >> 6) & 3;
} else if (mm->input.selector) {
rot.block = rot.overlay = rot.tex2 = rot.ecolor = simple_rot;
}
if (blockptr[ ns_off]==0)
stbvox_make_mesh_for_face(mm, rot, STBVOX_FACE_north, v_off, pos, basevert, vmesh+4*STBVOX_FACE_north, mesh);
if (blockptr[-ns_off]==0)
stbvox_make_mesh_for_face(mm, rot, STBVOX_FACE_south, v_off, pos, basevert, vmesh+4*STBVOX_FACE_south, mesh);
if (blockptr[ ew_off]==0)
stbvox_make_mesh_for_face(mm, rot, STBVOX_FACE_east , v_off, pos, basevert, vmesh+4*STBVOX_FACE_east, mesh);
if (blockptr[-ew_off]==0)
stbvox_make_mesh_for_face(mm, rot, STBVOX_FACE_west , v_off, pos, basevert, vmesh+4*STBVOX_FACE_west, mesh);
}
// void stbvox_make_mesh_for_block_with_geo(stbvox_mesh_maker *mm, stbvox_pos pos, int v_off)
//
// complex case for mesh generation: we have lots of different
// block types, and we don't want to generate faces of blocks
// if they're hidden by neighbors.
//
// we use lots of tables to determine this: we have a table
// which tells us what face type is generated for each type of
// geometry, and then a table that tells us whether that type
// is hidden by a neighbor.
#define STBVOX_MAX_GEOM 16
#define STBVOX_NUM_ROTATION 4
// this is used to determine if a face is ever generated at all
static unsigned char stbvox_hasface[STBVOX_MAX_GEOM][STBVOX_NUM_ROTATION] =
{
{ 0,0,0,0 }, // empty
{ 0,0,0,0 }, // knockout
{ 63,63,63,63 }, // solid
{ 63,63,63,63 }, // transp
{ 63,63,63,63 }, // slabs
{ 63,63,63,63 },
{ 1|2|4|48, 8|1|2|48, 4|8|1|48, 2|4|8|48, }, // floor slopes
{ 1|2|4|48, 8|1|2|48, 4|8|1|48, 2|4|8|48, }, // ceil slopes
{ 47,47,47,47 }, // wall-projected diagonal with down face
{ 31,31,31,31 }, // wall-projected diagonal with up face
{ 63,63,63,63 }, // crossed-pair has special handling, but avoid early-out
{ 63,63,63,63 }, // reserved
{ 63,63,63,63 },
{ 63,63,63,63 },
{ 63,63,63,63 },
{ 63,63,63,63 },
};
// these are the types of faces each block can have
enum
{
STBVOX_FT_none ,
STBVOX_FT_upper ,
STBVOX_FT_lower ,
STBVOX_FT_solid ,
STBVOX_FT_diag_012,
STBVOX_FT_diag_023,
STBVOX_FT_diag_013,
STBVOX_FT_diag_123,
STBVOX_FT_force , // can't be covered up, used for internal faces, also hides nothing
};
// these are additional geometry types used internally
enum
{
STBVOX_GEOM_internal_force = STBVOX_GEOM_count,
STBVOX_GEOM_internal_count
};
// this determines which face type above is visible on each side of the geometry
static unsigned char stbvox_facetype[STBVOX_GEOM_internal_count][6] =
{
{ 0, }, // STBVOX_GEOM_empty
{ STBVOX_FT_solid, STBVOX_FT_solid, STBVOX_FT_solid, STBVOX_FT_solid, STBVOX_FT_solid, STBVOX_FT_solid }, // knockout
{ STBVOX_FT_solid, STBVOX_FT_solid, STBVOX_FT_solid, STBVOX_FT_solid, STBVOX_FT_solid, STBVOX_FT_solid }, // solid
{ STBVOX_FT_force, STBVOX_FT_force, STBVOX_FT_force, STBVOX_FT_force, STBVOX_FT_force, STBVOX_FT_force }, // transp
{ STBVOX_FT_upper, STBVOX_FT_upper, STBVOX_FT_upper, STBVOX_FT_upper, STBVOX_FT_solid, STBVOX_FT_force },
{ STBVOX_FT_lower, STBVOX_FT_lower, STBVOX_FT_lower, STBVOX_FT_lower, STBVOX_FT_force, STBVOX_FT_solid },
{ STBVOX_FT_diag_123, STBVOX_FT_solid, STBVOX_FT_diag_023, STBVOX_FT_none, STBVOX_FT_force, STBVOX_FT_solid },
{ STBVOX_FT_diag_012, STBVOX_FT_solid, STBVOX_FT_diag_013, STBVOX_FT_none, STBVOX_FT_solid, STBVOX_FT_force },
{ STBVOX_FT_diag_123, STBVOX_FT_solid, STBVOX_FT_diag_023, STBVOX_FT_force, STBVOX_FT_none, STBVOX_FT_solid },
{ STBVOX_FT_diag_012, STBVOX_FT_solid, STBVOX_FT_diag_013, STBVOX_FT_force, STBVOX_FT_solid, STBVOX_FT_none },
{ STBVOX_FT_force, STBVOX_FT_force, STBVOX_FT_force, STBVOX_FT_force, 0,0 }, // crossed pair
{ STBVOX_FT_force, STBVOX_FT_force, STBVOX_FT_force, STBVOX_FT_force, STBVOX_FT_force, STBVOX_FT_force },
//0, }, // GEOM_force, show as empty so that neighbors are always visible
{ 0,0,0,0,0, STBVOX_FT_solid }, // floor vheight
{ 0,0,0,0,0, STBVOX_FT_solid }, // floor vheight
{ 0,0,0,0, STBVOX_FT_solid,0 }, // ceil vheight
{ 0,0,0,0, STBVOX_FT_solid,0 }, // ceil vheight
//{ STBVOX_FT_solid, STBVOX_FT_solid, STBVOX_FT_solid, STBVOX_FT_solid, STBVOX_FT_solid, STBVOX_FT_solid }, // internal force
};
// this table indicates whether, for each pair of types above, a face is visible.
// each value indicates whether a given type is visible for all neighbor types
static unsigned short stbvox_face_visible[9] =
{
// we encode the table by listing which cases cause *obscuration*, and bitwise inverting that
// table is pre-shifted by 5 to save a shift when it's accessed
(unsigned short) ((~0x07ff )<<5), // none is completely obscured by everything
(unsigned short) ((~((1<<STBVOX_FT_solid) | (1<<STBVOX_FT_upper) ))<<5), // upper
(unsigned short) ((~((1<<STBVOX_FT_solid) | (1<<STBVOX_FT_lower) ))<<5), // lower
(unsigned short) ((~((1<<STBVOX_FT_solid) ))<<5), // solid is only completely obscured only by solid
(unsigned short) ((~((1<<STBVOX_FT_solid) | (1<<STBVOX_FT_diag_013)))<<5), // diag012 matches diag013
(unsigned short) ((~((1<<STBVOX_FT_solid) | (1<<STBVOX_FT_diag_123)))<<5), // diag023 matches diag123
(unsigned short) ((~((1<<STBVOX_FT_solid) | (1<<STBVOX_FT_diag_012)))<<5), // diag013 matches diag012
(unsigned short) ((~((1<<STBVOX_FT_solid) | (1<<STBVOX_FT_diag_023)))<<5), // diag123 matches diag023
(unsigned short) ((~0 )<<5), // force is always rendered regardless, always forces neighbor
};
// the vertex heights of the block types, in binary vertex order (zyx):
// lower: SW, SE, NW, NE; upper: SW, SE, NW, NE
static stbvox_mesh_vertex stbvox_geometry_vheight[8][8] =
{
#define STBVOX_HEIGHTS(a,b,c,d,e,f,g,h) \
{ stbvox_vertex_p(0,0,a,0,0), \
stbvox_vertex_p(0,0,b,0,0), \
stbvox_vertex_p(0,0,c,0,0), \
stbvox_vertex_p(0,0,d,0,0), \
stbvox_vertex_p(0,0,e,0,0), \
stbvox_vertex_p(0,0,f,0,0), \
stbvox_vertex_p(0,0,g,0,0), \
stbvox_vertex_p(0,0,h,0,0) }
STBVOX_HEIGHTS(0,0,0,0, 2,2,2,2),
STBVOX_HEIGHTS(0,0,0,0, 2,2,2,2),
STBVOX_HEIGHTS(0,0,0,0, 2,2,2,2),
STBVOX_HEIGHTS(0,0,0,0, 2,2,2,2),
STBVOX_HEIGHTS(1,1,1,1, 2,2,2,2),
STBVOX_HEIGHTS(0,0,0,0, 1,1,1,1),
STBVOX_HEIGHTS(0,0,0,0, 0,0,2,2),
STBVOX_HEIGHTS(2,2,0,0, 2,2,2,2),
};
// rotate vertices defined as [z][y][x] coords
static unsigned char stbvox_rotate_vertex[8][4] =
{
{ 0,1,3,2 }, // zyx=000
{ 1,3,2,0 }, // zyx=001
{ 2,0,1,3 }, // zyx=010
{ 3,2,0,1 }, // zyx=011
{ 4,5,7,6 }, // zyx=100
{ 5,7,6,4 }, // zyx=101
{ 6,4,5,7 }, // zyx=110
{ 7,6,4,5 }, // zyx=111
};
void stbvox_make_mesh_for_block_with_geo(stbvox_mesh_maker *mm, stbvox_pos pos, int v_off)
{
int ns_off = mm->y_stride_in_bytes;
int ew_off = mm->x_stride_in_bytes;
int visible_faces, visible_base;
unsigned char mesh;
// first gather the geometry info for this block and all neighbors
unsigned char bt, nbt[6];
unsigned char geo, ngeo[6];
unsigned char rot, nrot[6];
bt = mm->input.blocktype[v_off];
nbt[0] = mm->input.blocktype[v_off + ew_off];
nbt[1] = mm->input.blocktype[v_off + ns_off];
nbt[2] = mm->input.blocktype[v_off - ew_off];
nbt[3] = mm->input.blocktype[v_off - ns_off];
nbt[4] = mm->input.blocktype[v_off + 1];
nbt[5] = mm->input.blocktype[v_off - 1];
if (mm->input.geometry) {
int i;
geo = mm->input.geometry[v_off];
ngeo[0] = mm->input.geometry[v_off + ew_off];
ngeo[1] = mm->input.geometry[v_off + ns_off];
ngeo[2] = mm->input.geometry[v_off - ew_off];
ngeo[3] = mm->input.geometry[v_off - ns_off];
ngeo[4] = mm->input.geometry[v_off + 1];
ngeo[5] = mm->input.geometry[v_off - 1];
rot = (geo >> 4) & 3;
geo &= 15;
for (i=0; i < 6; ++i) {
nrot[i] = (ngeo[i] >> 4) & 3;
ngeo[i] &= 15;
}
} else {
int i;
assert(mm->input.block_geometry);
geo = mm->input.block_geometry[bt];
for (i=0; i < 6; ++i)
ngeo[i] = mm->input.block_geometry[nbt[i]];
if (mm->input.selector) {
rot = (mm->input.selector[v_off ] >> 4) & 3;
nrot[0] = (mm->input.selector[v_off + ew_off] >> 4) & 3;
nrot[1] = (mm->input.selector[v_off + ns_off] >> 4) & 3;
nrot[2] = (mm->input.selector[v_off - ew_off] >> 4) & 3;
nrot[3] = (mm->input.selector[v_off - ns_off] >> 4) & 3;
nrot[4] = (mm->input.selector[v_off + 1] >> 4) & 3;
nrot[5] = (mm->input.selector[v_off - 1] >> 4) & 3;
} else {
rot = (geo>>4)&3;
geo &= 15;
for (i=0; i < 6; ++i) {
nrot[i] = (ngeo[i]>>4)&3;
ngeo[i] &= 15;
}
}
}
#ifdef STBVOX_ROTATION_IN_LIGHTING
rot = mm->input.lighting[v_off] & 3;
nrot[0] = (mm->input.lighting[v_off + ew_off]) & 3;
nrot[1] = (mm->input.lighting[v_off + ns_off]) & 3;
nrot[2] = (mm->input.lighting[v_off - ew_off]) & 3;
nrot[3] = (mm->input.lighting[v_off - ns_off]) & 3;
nrot[4] = (mm->input.lighting[v_off + 1]) & 3;
nrot[5] = (mm->input.lighting[v_off - 1]) & 3;
#endif
if (geo == STBVOX_GEOM_transp) {
// transparency has a special rule: if the blocktype is the same,
// and the faces are compatible, then can hide them; otherwise,
// force them on
// Note that this means we don't support any transparentshapes other
// than solid blocks, since detecting them is too complicated. If
// you wanted to do something like minecraft water, you probably
// should just do that with a separate renderer anyway. (We don't
// support transparency sorting so you need to use alpha test
// anyway)
int i;
for (i=0; i < 6; ++i)
if (nbt[i] != bt) {
nbt[i] = 0;
ngeo[i] = STBVOX_GEOM_empty;
} else
ngeo[i] = STBVOX_GEOM_solid;
geo = STBVOX_GEOM_solid;
}
// now compute the face visibility
visible_base = stbvox_hasface[geo][rot];
// @TODO: assert(visible_base != 0); // we should have early-outted earlier in this case
visible_faces = 0;
// now, for every face that might be visible, check if neighbor hides it
if (visible_base & (1 << STBVOX_FACE_east)) {
int type = stbvox_facetype[ geo ][(STBVOX_FACE_east+ rot )&3];
int ntype = stbvox_facetype[ngeo[0]][(STBVOX_FACE_west+nrot[0])&3];
visible_faces |= ((stbvox_face_visible[type]) >> (ntype + 5 - STBVOX_FACE_east)) & (1 << STBVOX_FACE_east);
}
if (visible_base & (1 << STBVOX_FACE_north)) {
int type = stbvox_facetype[ geo ][(STBVOX_FACE_north+ rot )&3];
int ntype = stbvox_facetype[ngeo[1]][(STBVOX_FACE_south+nrot[1])&3];
visible_faces |= ((stbvox_face_visible[type]) >> (ntype + 5 - STBVOX_FACE_north)) & (1 << STBVOX_FACE_north);
}
if (visible_base & (1 << STBVOX_FACE_west)) {
int type = stbvox_facetype[ geo ][(STBVOX_FACE_west+ rot )&3];
int ntype = stbvox_facetype[ngeo[2]][(STBVOX_FACE_east+nrot[2])&3];
visible_faces |= ((stbvox_face_visible[type]) >> (ntype + 5 - STBVOX_FACE_west)) & (1 << STBVOX_FACE_west);
}
if (visible_base & (1 << STBVOX_FACE_south)) {
int type = stbvox_facetype[ geo ][(STBVOX_FACE_south+ rot )&3];
int ntype = stbvox_facetype[ngeo[3]][(STBVOX_FACE_north+nrot[3])&3];
visible_faces |= ((stbvox_face_visible[type]) >> (ntype + 5 - STBVOX_FACE_south)) & (1 << STBVOX_FACE_south);
}
if (visible_base & (1 << STBVOX_FACE_up)) {
int type = stbvox_facetype[ geo ][STBVOX_FACE_up];
int ntype = stbvox_facetype[ngeo[4]][STBVOX_FACE_down];
visible_faces |= ((stbvox_face_visible[type]) >> (ntype + 5 - STBVOX_FACE_up)) & (1 << STBVOX_FACE_up);
}
if (visible_base & (1 << STBVOX_FACE_down)) {
int type = stbvox_facetype[ geo ][STBVOX_FACE_down];
int ntype = stbvox_facetype[ngeo[5]][STBVOX_FACE_up];
visible_faces |= ((stbvox_face_visible[type]) >> (ntype + 5 - STBVOX_FACE_down)) & (1 << STBVOX_FACE_down);
}
if (geo == STBVOX_GEOM_force)
geo = STBVOX_GEOM_solid;
assert((geo == STBVOX_GEOM_crossed_pair) ? (visible_faces == 15) : 1);
// now we finally know for sure which faces are getting generated
if (visible_faces == 0)
return;
mesh = mm->default_mesh;
if (mm->input.selector)
mesh = mm->input.selector[v_off];
if (geo <= STBVOX_GEOM_ceil_slope_north_is_bottom) {
// this is the simple case, we can just use regular block gen with special vmesh calculated with vheight
stbvox_mesh_vertex basevert;
stbvox_mesh_vertex vmesh[6][4];
stbvox_rotate rotate = { 0,0,0,0 };
unsigned char simple_rot = 0;
int i;
// we only need to do this for the displayed faces, but it's easier
// to just do it up front; @OPTIMIZE check if it's faster to do it
// for visible faces only
for (i=0; i < 6*4; ++i) {
int vert = stbvox_vertex_selector[0][i];
vert = stbvox_rotate_vertex[vert][rot];
vmesh[0][i] = stbvox_vmesh_pre_vheight[0][i]
+ stbvox_geometry_vheight[geo][vert];
}
basevert = stbvox_vertex_p(pos.x, pos.y, pos.z<<mm->precision_z , 0,0);
if (mm->input.selector) {
mesh = mm->input.selector[v_off];
}
// check if we're going off the end
if (mm->output_cur[mesh][0] + mm->output_size[mesh][0]*6 > mm->output_end[mesh][0]) {
assert(0);
return;
}
if (visible_faces & (1 << STBVOX_FACE_up))
stbvox_make_mesh_for_face(mm, rotate, STBVOX_FACE_up , v_off, pos, basevert, vmesh[STBVOX_FACE_up], mesh);
if (visible_faces & (1 << STBVOX_FACE_down))
stbvox_make_mesh_for_face(mm, rotate, STBVOX_FACE_down, v_off, pos, basevert, vmesh[STBVOX_FACE_down], mesh);
if (mm->input.rotate) {
unsigned char val = mm->input.rotate[v_off];
rotate.block = (val >> 0) & 3;
rotate.overlay = (val >> 2) & 3;
rotate.tex2 = (val >> 4) & 3;
rotate.ecolor = (val >> 6) & 3;
} else if (mm->input.selector) {
rotate.block = rotate.overlay = rotate.tex2 = rotate.ecolor = simple_rot;
}
if (visible_faces & (1 << STBVOX_FACE_north))
stbvox_make_mesh_for_face(mm, rotate, STBVOX_FACE_north, v_off, pos, basevert, vmesh[STBVOX_FACE_north], mesh);
if (visible_faces & (1 << STBVOX_FACE_south))
stbvox_make_mesh_for_face(mm, rotate, STBVOX_FACE_south, v_off, pos, basevert, vmesh[STBVOX_FACE_south], mesh);
if (visible_faces & (1 << STBVOX_FACE_east))
stbvox_make_mesh_for_face(mm, rotate, STBVOX_FACE_east , v_off, pos, basevert, vmesh[STBVOX_FACE_east ], mesh);
if (visible_faces & (1 << STBVOX_FACE_west))
stbvox_make_mesh_for_face(mm, rotate, STBVOX_FACE_west , v_off, pos, basevert, vmesh[STBVOX_FACE_west ], mesh);
}
if (geo >= STBVOX_GEOM_floor_vheight_02) {
// this case can also be generated with regular block gen with special vmesh,
// except:
// if we want to generate middle diagonal for 'weird' blocks
// it's more complicated to detect neighbor matchups
stbvox_mesh_vertex vmesh[6][4];
stbvox_mesh_vertex cube[8];
stbvox_mesh_vertex basevert;
stbvox_rotate rotate = { 0,0,0,0 };
unsigned char simple_rot = 0;
unsigned char ht[4];
// extract the heights
if (mm->input.vheight) {
unsigned char v = mm->input.vheight[v_off];
ht[0] = (v >> 0) & 3;
ht[1] = (v >> 2) & 3;
ht[2] = (v >> 4) & 3;
ht[3] = (v >> 6) & 3;
} else if (mm->input.block_vheight) {
unsigned char v = mm->input.block_vheight[bt];
// @TODO: these need to be rotated by 'rotate'
ht[0] = (v >> 0) & 3;
ht[1] = (v >> 2) & 3;
ht[2] = (v >> 4) & 3;
ht[3] = (v >> 6) & 3;
} else {
assert(mm->input.geometry);
}
if (geo >= STBVOX_GEOM_ceil_vheight_02) {
cube[0] = stbvox_vertex_p(0,0,0,0,0);
cube[1] = stbvox_vertex_p(0,0,0,0,0);
cube[2] = stbvox_vertex_p(0,0,0,0,0);
cube[3] = stbvox_vertex_p(0,0,0,0,0);
cube[4] = stbvox_vertex_p(0,0,ht[0],0,0);
cube[5] = stbvox_vertex_p(0,0,ht[1],0,0);
cube[6] = stbvox_vertex_p(0,0,ht[2],0,0);
cube[7] = stbvox_vertex_p(0,0,ht[3],0,0);
} else {
cube[0] = stbvox_vertex_p(0,0,ht[0],0,0);
cube[1] = stbvox_vertex_p(0,0,ht[1],0,0);
cube[2] = stbvox_vertex_p(0,0,ht[2],0,0);
cube[3] = stbvox_vertex_p(0,0,ht[3],0,0);
cube[4] = stbvox_vertex_p(0,0,0,0,0);
cube[5] = stbvox_vertex_p(0,0,0,0,0);
cube[6] = stbvox_vertex_p(0,0,0,0,0);
cube[7] = stbvox_vertex_p(0,0,0,0,0);
}
if (!mm->input.vheight && mm->input.block_vheight) {
int i;
// apply rotation
for (i=0; i < 6*4; ++i) {
int vert = stbvox_vertex_selector[0][i];
vert = stbvox_rotate_vertex[vert][rot];
vmesh[0][i] = stbvox_vmesh_pre_vheight[0][i]
+ cube[vert];
}
} else {
int i;
for (i=0; i < 6*4; ++i) {
int vert = stbvox_vertex_selector[0][i];
vmesh[0][i] = stbvox_vmesh_pre_vheight[0][i]
+ cube[vert];
}
}
basevert = stbvox_vertex_p(pos.x, pos.y, pos.z<<mm->precision_z , 0,0);
// check if we're going off the end
if (mm->output_cur[mesh][0] + mm->output_size[mesh][0]*6 > mm->output_end[mesh][0]) {
assert(0);
return;
}
if (visible_faces & (1 << STBVOX_FACE_up))
stbvox_make_mesh_for_face(mm, rotate, STBVOX_FACE_up , v_off, pos, basevert, vmesh[STBVOX_FACE_up], mesh);
if (visible_faces & (1 << STBVOX_FACE_down))
stbvox_make_mesh_for_face(mm, rotate, STBVOX_FACE_down, v_off, pos, basevert, vmesh[STBVOX_FACE_down], mesh);
if (mm->input.rotate) {
unsigned char val = mm->input.rotate[v_off];
rotate.block = (val >> 0) & 3;
rotate.overlay = (val >> 2) & 3;
rotate.tex2 = (val >> 4) & 3;
rotate.ecolor = (val >> 6) & 3;
} else if (mm->input.selector) {
rotate.block = rotate.overlay = rotate.tex2 = rotate.ecolor = simple_rot;
}
if (visible_faces & (1 << STBVOX_FACE_north))
stbvox_make_mesh_for_face(mm, rotate, STBVOX_FACE_north, v_off, pos, basevert, vmesh[STBVOX_FACE_north], mesh);
if (visible_faces & (1 << STBVOX_FACE_south))
stbvox_make_mesh_for_face(mm, rotate, STBVOX_FACE_south, v_off, pos, basevert, vmesh[STBVOX_FACE_south], mesh);
if (visible_faces & (1 << STBVOX_FACE_east))
stbvox_make_mesh_for_face(mm, rotate, STBVOX_FACE_east , v_off, pos, basevert, vmesh[STBVOX_FACE_east ], mesh);
if (visible_faces & (1 << STBVOX_FACE_west))
stbvox_make_mesh_for_face(mm, rotate, STBVOX_FACE_west , v_off, pos, basevert, vmesh[STBVOX_FACE_west ], mesh);
}
if (geo == STBVOX_GEOM_crossed_pair) {
// this can be generated with a special vmesh
stbvox_mesh_vertex basevert = stbvox_vertex_p(pos.x, pos.y, pos.z<<mm->precision_z , 0,0);
stbvox_rotate rot = { 0,0,0,0 };
unsigned char simple_rot;
unsigned char mesh = mm->default_mesh;
if (mm->input.selector) {
mesh = mm->input.selector[v_off];
simple_rot = mesh >> 4;
mesh &= 15;
}
// check if we're going off the end
if (mm->output_cur[mesh][0] + mm->output_size[mesh][0]*4 > mm->output_end[mesh][0]) {
assert(0);
return;
}
if (mm->input.rotate) {
unsigned char val = mm->input.rotate[v_off];
rot.block = (val >> 0) & 3;
rot.overlay = (val >> 2) & 3;
rot.tex2 = (val >> 4) & 3;
rot.ecolor = (val >> 6) & 3;
} else if (mm->input.selector) {
rot.block = rot.overlay = rot.tex2 = rot.ecolor = simple_rot;
}
stbvox_make_mesh_for_face(mm, rot, STBVOX_FACE_north, v_off, pos, basevert, stbvox_vmesh_crossed_pair[STBVOX_FACE_north], mesh);
stbvox_make_mesh_for_face(mm, rot, STBVOX_FACE_south, v_off, pos, basevert, stbvox_vmesh_crossed_pair[STBVOX_FACE_south], mesh);
stbvox_make_mesh_for_face(mm, rot, STBVOX_FACE_east , v_off, pos, basevert, stbvox_vmesh_crossed_pair[STBVOX_FACE_east ], mesh);
stbvox_make_mesh_for_face(mm, rot, STBVOX_FACE_west , v_off, pos, basevert, stbvox_vmesh_crossed_pair[STBVOX_FACE_west ], mesh);
}
// @TODO
// STBVOX_GEOM_floor_slope_north_is_top_as_wall,
// STBVOX_GEOM_ceil_slope_north_is_bottom_as_wall,
}
void stbvox_make_mesh_for_column(stbvox_mesh_maker *mm, int x, int y, int z0)
{
stbvox_pos pos = { x,y,0 };
int v_off = x * mm->x_stride_in_bytes + y * mm->y_stride_in_bytes;
int ns_off = mm->y_stride_in_bytes;
int ew_off = mm->x_stride_in_bytes;
if (mm->input.geometry) {
unsigned char *bt = mm->input.blocktype + v_off;
unsigned char *geo = mm->input.geometry + v_off;
int z;
for (z=z0; z < mm->z1; ++z) {
if (bt[z] && ( !bt[z+ns_off] || !STBVOX_GET_GEO(geo[z+ns_off]) || !bt[z-ns_off] || !STBVOX_GET_GEO(geo[z-ns_off])
|| !bt[z+ew_off] || !STBVOX_GET_GEO(geo[z+ew_off]) || !bt[z-ew_off] || !STBVOX_GET_GEO(geo[z-ew_off])))
{ // TODO check up and down
pos.z = z;
stbvox_make_mesh_for_block_with_geo(mm, pos, v_off+z);
}
}
} else if (mm->input.block_geometry) {
int z;
unsigned char *bt = mm->input.blocktype + v_off;
unsigned char *geo = mm->input.block_geometry;
for (z=z0; z < mm->z1; ++z) {
if (bt[z] && ( geo[bt[z+ns_off]] != STBVOX_GEOM_solid
|| geo[bt[z-ns_off]] != STBVOX_GEOM_solid
|| geo[bt[z+ew_off]] != STBVOX_GEOM_solid
|| geo[bt[z-ew_off]] != STBVOX_GEOM_solid
|| geo[bt[z-1]] != STBVOX_GEOM_solid
|| geo[bt[z+1]] != STBVOX_GEOM_solid))
{
pos.z = z;
stbvox_make_mesh_for_block_with_geo(mm, pos, v_off+z);
}
}
} else {
unsigned char *bt = mm->input.blocktype + v_off;
int z;
stbvox_mesh_vertex *vmesh = mm->precision_z ? stbvox_vmesh_delta_half_z[0] : stbvox_vmesh_delta_normal[0];
for (z=z0; z < mm->z1; ++z) {
// if it's solid and at least one neighbor isn't solid
if (bt[z] && (!bt[z+ns_off] || !bt[z-ns_off] || !bt[z+ew_off] || !bt[z-ew_off] || !bt[z-1] || !bt[z+1])) {
pos.z = z;
stbvox_make_mesh_for_block(mm, pos, v_off+z, vmesh);
}
}
}
}
void stbvox_bring_up_to_date(stbvox_mesh_maker *mm)
{
if (mm->config_dirty) {
int i;
mm->num_mesh_slots = (mm->tags & STBVOX_TAG_face_sampled ? 2 : 1);
for (i=0; i < STBVOX_MAX_MESHES; ++i) {
if (mm->num_mesh_slots == 2) {
mm->output_size[i][0] = 16;
mm->output_step[i][0] = 4;
mm->output_size[i][1] = 4;
mm->output_step[i][1] = 4;
} else {
mm->output_size[i][0] = 32;
mm->output_step[i][0] = 8;
}
}
mm->config_dirty = 0;
}
}
int stbvox_make_mesh(stbvox_mesh_maker *mm)
{
int x,y;
stbvox_bring_up_to_date(mm);
if (mm->cur_x || mm->cur_y || mm->cur_z) {
stbvox_make_mesh_for_column(mm, mm->cur_x, mm->cur_y, mm->cur_z);
++mm->cur_y;
while (mm->cur_y < mm->y1)
stbvox_make_mesh_for_column(mm, mm->cur_x, mm->cur_y++, mm->z0);
}
for (x=mm->x0; x < mm->x1; ++x) {
for (y=mm->y0; y < mm->y1; ++y) {
stbvox_make_mesh_for_column(mm, x, y, mm->z0);
}
}
return 1;
}
void stbvox_init_mesh_maker(stbvox_mesh_maker *mm)
{
memset(mm, 0, sizeof(*mm));
stbvox_build_default_palette();
mm->tags = STBVOX_TAG_textured;
mm->precision_z = 1;
mm->config_dirty = 1;
mm->default_mesh = 0;
}
int stbvox_get_buffer_count(stbvox_mesh_maker *mm)
{
stbvox_bring_up_to_date(mm);
return mm->num_mesh_slots;
}
int stbvox_get_buffer_size_per_quad(stbvox_mesh_maker *mm, int n)
{
return mm->output_size[0][n];
}
void stbvox_reset_buffers(stbvox_mesh_maker *mm)
{
int i;
for (i=0; i < STBVOX_MAX_MESHES*STBVOX_MAX_MESH_SLOTS; ++i) {
mm->output_cur[0][i] = 0;
mm->output_buffer[0][i] = 0;
}
}
void stbvox_set_buffer(stbvox_mesh_maker *mm, int mesh, int slot, void *buffer, size_t len)
{
int i;
stbvox_bring_up_to_date(mm);
mm->output_buffer[mesh][slot] = (char *) buffer;
mm->output_cur [mesh][slot] = (char *) buffer;
mm->output_len [mesh][slot] = len;
mm->output_end [mesh][slot] = (char *) buffer + len;
for (i=0; i < STBVOX_MAX_MESH_SLOTS; ++i) {
if (mm->output_buffer[mesh][i]) {
assert(mm->output_len[mesh][i] / mm->output_size[mesh][i] == mm->output_len[mesh][slot] / mm->output_size[mesh][slot]);
}
}
}
void stbvox_set_default_mesh(stbvox_mesh_maker *mm, int mesh)
{
mm->default_mesh = mesh;
}
int stbvox_get_quad_count(stbvox_mesh_maker *mm, int mesh)
{
return (mm->output_cur[mesh][0] - mm->output_buffer[mesh][0]) / mm->output_size[mesh][0];
}
stbvox_input_description *stbvox_get_input_description(stbvox_mesh_maker *mm)
{
return &mm->input;
}
void stbvox_set_input_range(stbvox_mesh_maker *mm, int x0, int y0, int z0, int x1, int y1, int z1)
{
mm->x0 = x0;
mm->y0 = y0;
mm->z0 = z0;
mm->x1 = x1;
mm->y1 = y1;
mm->z1 = z1;
mm->cur_x = x0;
mm->cur_y = y0;
mm->cur_z = z0;
// @TODO validate that this range is representable in this mode
}
void stbvox_get_transform(stbvox_mesh_maker *mm, float transform[3][3])
{
// scale
transform[0][0] = 1.0;
transform[0][1] = 1.0;
transform[0][2] = mm->precision_z ? 0.5f : 1.0f;
// translation
transform[1][0] = (float) (mm->pos_x);
transform[1][1] = (float) (mm->pos_y);
transform[1][2] = (float) (mm->pos_z);
// texture coordinate projection translation
transform[2][0] = (float) (mm->pos_x & 63); // @TODO depends on max texture scale
transform[2][1] = (float) (mm->pos_y & 63);
transform[2][2] = (float) (mm->pos_z & 63);
}
void stbvox_get_bounds(stbvox_mesh_maker *mm, float bounds[2][3])
{
bounds[0][0] = (float) (mm->pos_x + mm->x0);
bounds[0][1] = (float) (mm->pos_y + mm->y0);
bounds[0][2] = (float) (mm->pos_z + mm->z0);
bounds[1][0] = (float) (mm->pos_x + mm->x1);
bounds[1][1] = (float) (mm->pos_y + mm->y1);
bounds[1][2] = (float) (mm->pos_z + mm->z1);
}
void stbvox_set_mesh_coordinates(stbvox_mesh_maker *mm, int x, int y, int z)
{
mm->pos_x = x;
mm->pos_y = y;
mm->pos_z = z;
}
void stbvox_set_input_stride(stbvox_mesh_maker *mm, int x_stride_in_bytes, int y_stride_in_bytes)
{
int f,v;
mm->x_stride_in_bytes = x_stride_in_bytes;
mm->y_stride_in_bytes = y_stride_in_bytes;
for (f=0; f < 6; ++f) {
for (v=0; v < 4; ++v) {
mm->cube_vertex_offset[f][v] = stbvox_vertex_vector[f][v][0] * mm->x_stride_in_bytes
+ stbvox_vertex_vector[f][v][1] * mm->y_stride_in_bytes
+ stbvox_vertex_vector[f][v][2] ;
mm->vertex_gather_offset[f][v] = (stbvox_vertex_vector[f][v][0]-1) * mm->x_stride_in_bytes
+ (stbvox_vertex_vector[f][v][1]-1) * mm->y_stride_in_bytes
+ (stbvox_vertex_vector[f][v][2]-1) ;
}
}
}
// this is designed to allow you to call it multiple times to change the mode
// in case you're using multiple variants for different purposes
void stbvox_config_use_gl(stbvox_mesh_maker *mm, int use_tex_buffer, int use_gl_modelview, int use_gl_fragment)
{
mm->config_dirty = 1;
mm->tags |= STBVOX_TAG_gl | STBVOX_TAG_all;
if (use_tex_buffer) {
mm->tags &= ~STBVOX_TAG_face_attribute;
mm->tags |= STBVOX_TAG_face_sampled;
} else {
mm->tags &= ~STBVOX_TAG_face_sampled;
mm->tags |= STBVOX_TAG_face_attribute;
}
if (use_gl_modelview)
mm->tags |= STBVOX_TAG_gl_modelview;
else
mm->tags &= ~STBVOX_TAG_gl_modelview;
mm->tags &= ~(STBVOX_TAG_glsl_130 | STBVOX_TAG_glsl_150 | STBVOX_TAG_glsl_150_compatibility);
if (use_tex_buffer)
if (use_gl_modelview)
mm->tags |= STBVOX_TAG_glsl_150_compatibility;
else
mm->tags |= STBVOX_TAG_glsl_150_compatibility;
else
mm->tags |= STBVOX_TAG_glsl_130;
}
void stbvox_config_set_z_precision(stbvox_mesh_maker *mm, int z_fractional_bits)
{
assert(z_fractional_bits >= 0 && z_fractional_bits <= 1);
mm->precision_z = z_fractional_bits;
}
#endif // STB_VOXEL_RENDER_IMPLEMENTATION
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