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Nuklear/demo/opengl.c

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/*
Copyright (c) 2015
vurtun <polygone@gmx.net>
MIT licence
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdarg.h>
#include <string.h>
#include <math.h>
#include <assert.h>
#include <math.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <SDL2/SDL.h>
#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_GLYPH_H
/* macros */
#define DTIME 17
#define FONT_ATLAS_DEPTH 4
#define CIRCLE_SEGMENTS 22
/* macros */
#define MIN(a,b) ((a) < (b) ? (a) : (b))
#define MAX(a,b) ((a) < (b) ? (b) : (a))
#define CLAMP(i,v,x) (MAX(MIN(v,x), i))
#define LEN(a) (sizeof(a)/sizeof(a)[0])
#define UNUSED(a) ((void)(a))
#define GUI_USE_FIXED_TYPES
#define GUI_ASSERT(expr) assert(expr)
#include "../gui.h"
#include "demo.c"
struct texCoord {
float u;
float v;
};
enum font_atlas_dimension {
FONT_ATLAS_DIM_64 = 64,
FONT_ATLAS_DIM_128 = 128,
FONT_ATLAS_DIM_256 = 256,
FONT_ATLAS_DIM_512 = 512,
FONT_ATLAS_DIM_1024 = 1024,
FONT_ATLAS_DIM_2048 = 2048
};
struct font_atlas {
enum font_atlas_dimension dim;
gui_size range;
gui_size size;
gui_byte *memory;
};
struct font_glyph {
unsigned int code;
float xadvance;
short width, height;
float xoff, yoff;
struct texCoord uv[2];
};
struct font {
float height;
float scale;
GLuint texture;
unsigned int glyph_count;
struct font_glyph *glyphes;
const struct font_glyph *fallback;
};
static void
die(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fputs("\n", stderr);
exit(EXIT_FAILURE);
}
static char*
file_load(const char* path, size_t* siz)
{
char *buf;
FILE *fd = fopen(path, "rb");
if (!fd) {
die("Failed to open file: %s\n", path);
}
fseek(fd, 0, SEEK_END);
*siz = (size_t)ftell(fd);
fseek(fd, 0, SEEK_SET);
buf = calloc(*siz, 1);
fread(buf, *siz, 1, fd);
fclose(fd);
return buf;
}
static void
font_load_glyph(unsigned int code, struct font_glyph *glyph, FT_GlyphSlot slot)
{
glyph->code = code;
glyph->width = (short)slot->bitmap.width;
glyph->height = (short)slot->bitmap.rows;
glyph->xoff = (float)slot->bitmap_left;
glyph->yoff = (float)slot->bitmap_top;
glyph->xadvance = (float)(slot->advance.x >> 6);
}
static void
font_load_glyphes(FT_Face face, struct font *font, size_t range)
{
size_t i;
int ft_err;
for (i = 0; i < range; ++i) {
unsigned int index = FT_Get_Char_Index(face, i);
if (!index) continue;
ft_err = FT_Load_Glyph(face, index, 0);
if (ft_err) continue;
ft_err = FT_Render_Glyph(face->glyph, FT_RENDER_MODE_NORMAL);
if (ft_err) continue;
font_load_glyph(index, &font->glyphes[i], face->glyph);
}
}
static void
font_pack_glyphes(struct font *font, float width, float height, size_t range)
{
size_t i;
float xoff = 0, yoff = 0;
float max_height = 0.0f;
for (i = 0; i < range; ++i) {
struct font_glyph *glyph = &font->glyphes[i];
if ((xoff + glyph->width) > width) {
yoff += max_height;
max_height = 0.0f;
xoff = 0.0f;
}
glyph->uv[0].u = xoff / width;
glyph->uv[0].v = yoff / height;
glyph->uv[1].u = (xoff + glyph->width) / width;
glyph->uv[1].v = (yoff + glyph->height) / height;
if (glyph->height > max_height)
max_height = glyph->height;
xoff += glyph->width;
}
}
static void
font_atlas_blit(struct font_atlas *atlas, FT_GlyphSlot glyph,
size_t off_x, size_t off_y)
{
size_t y, x;
size_t width = glyph->bitmap.width;
size_t height = glyph->bitmap.rows;
const size_t pitch = atlas->dim * FONT_ATLAS_DEPTH;
for (y = 0; y < height; y++) {
size_t x_off = off_x * FONT_ATLAS_DEPTH;
size_t y_off = (off_y + y) * pitch;
unsigned char *dst = &atlas->memory[y_off + x_off];
for (x = 0; x < width; ++x) {
dst[0] = 255;
dst[1] = 255;
dst[2] = 255;
dst[3] = glyph->bitmap.buffer[y * width + x];
dst += FONT_ATLAS_DEPTH;
}
}
}
static void
font_bake_glyphes(FT_Face face, struct font_atlas *atlas,
const struct font *font)
{
size_t i;
int ft_err;
for (i = 0; i < atlas->range; ++i) {
size_t x, y;
struct font_glyph *glyph = &font->glyphes[i];
unsigned int index = FT_Get_Char_Index(face, i);
if (!index) continue;
ft_err = FT_Load_Glyph(face, index, 0);
if (ft_err) continue;
ft_err = FT_Render_Glyph(face->glyph, FT_RENDER_MODE_NORMAL);
if (ft_err) continue;
x = (gui_size)(glyph->uv[0].u * (gui_float)atlas->dim);
y = (gui_size)(glyph->uv[0].v * (gui_float)atlas->dim);
font_atlas_blit(atlas, face->glyph, x, y);
}
}
static int
font_load(struct font *font, struct font_atlas *atlas, unsigned int height,
const unsigned char *data, size_t size)
{
int ret = 1;
FT_Library ft_lib;
FT_Face ft_face;
assert(font);
assert(atlas);
assert(font->glyphes);
assert(atlas->memory);
if (!font || !atlas)
return gui_false;
if (!font->glyphes || !atlas->memory)
return gui_false;
if (FT_Init_FreeType(&ft_lib))
return gui_false;
if (FT_New_Memory_Face(ft_lib, data, (FT_Long)size, 0, &ft_face))
goto cleanup;
if (FT_Select_Charmap(ft_face, FT_ENCODING_UNICODE))
goto failed;
if (FT_Set_Char_Size(ft_face, height << 6, height << 6, 96, 96))
goto failed;
font_load_glyphes(ft_face, font, atlas->range);
font_pack_glyphes(font, atlas->dim, atlas->dim, atlas->range);
font_bake_glyphes(ft_face, atlas, font);
failed:
FT_Done_Face(ft_face);
cleanup:
FT_Done_FreeType(ft_lib);
return ret;
}
static gui_size
font_get_text_width(gui_handle handle, const gui_char *t, gui_size l)
{
long unicode;
size_t text_width = 0;
const struct font_glyph *glyph;
size_t text_len = 0;
size_t glyph_len;
struct font *font = handle.ptr;
assert(font);
if (!t || !l) return 0;
glyph_len = gui_utf_decode(t, &unicode, l);
while (text_len < l && glyph_len) {
if (unicode == GUI_UTF_INVALID) return 0;
glyph = (unicode < font->glyph_count) ? &font->glyphes[unicode] : font->fallback;
glyph = (glyph->code == 0) ? font->fallback : glyph;
text_width += (gui_size)((float)glyph->xadvance * font->scale);
glyph_len = gui_utf_decode(t + text_len, &unicode, l - text_len);
text_len += glyph_len;
}
return (l >= 1) ? text_width : 0;
}
static void
font_draw_text(const struct font *font, float x, float y, float h,
const gui_byte *color, const char *text, size_t len)
{
size_t text_len;
long unicode;
const struct font_glyph *g;
text_len = gui_utf_decode(text, &unicode, len);
glBindTexture(GL_TEXTURE_2D, font->texture);
glColor4ub(color[0], color[1], color[2], color[3]);
glBegin(GL_QUADS);
while (text_len <= len) {
float gx, gy, gh, gw;
float char_width = 0;
if (unicode == GUI_UTF_INVALID) break;
g = (unicode < font->glyph_count) ?
&font->glyphes[unicode] :
font->fallback;
g = (g->code == 0) ? font->fallback : g;
gx = x + (g->xoff * font->scale);
gy = y + (font->height/2) + (h/2) - (g->yoff * font->scale);
gw = (float)g->width * font->scale;
gh = (float)g->height * font->scale;
char_width = g->xadvance * font->scale;
glTexCoord2f(g->uv[0].u, g->uv[0].v);
glVertex2f(gx, gy);
glTexCoord2f(g->uv[1].u, g->uv[0].v);
glVertex2f(gx + gw, gy);
glTexCoord2f(g->uv[1].u, g->uv[1].v);
glVertex2f(gx + gw, gy + gh);
glTexCoord2f(g->uv[0].u, g->uv[1].v);
glVertex2f(gx, gy + gh);
text_len += gui_utf_decode(text + text_len, &unicode, len - text_len);
x += char_width;
}
glEnd();
glBindTexture(GL_TEXTURE_2D, 0);
}
static void
font_del(struct font *font)
{
glDeleteTextures(1, &font->texture);
free(font->glyphes);
free(font);
}
static struct font*
font_new(const char *path, unsigned int font_height, unsigned int bake_height,
size_t range, enum font_atlas_dimension dim)
{
gui_byte *ttf_blob;
gui_size ttf_blob_size;
struct font_atlas atlas;
struct font *font = calloc(sizeof(struct font), 1);
atlas.dim = dim;
atlas.range = range;
atlas.size = atlas.dim * atlas.dim * FONT_ATLAS_DEPTH;
atlas.memory = calloc((gui_size)atlas.size, 1);
font->glyph_count = (unsigned int)atlas.range;
font->glyphes = calloc(atlas.range, sizeof(struct font_glyph));
font->fallback = &font->glyphes['?'];
font->scale = (float)font_height / (gui_float)bake_height;
font->height = (float)font_height;
ttf_blob = (unsigned char*)file_load(path, &ttf_blob_size);
if (!font_load(font, &atlas, bake_height, ttf_blob, ttf_blob_size))
goto failed;
glGenTextures(1, &font->texture);
glBindTexture(GL_TEXTURE_2D, font->texture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, dim, dim, 0,
GL_RGBA, GL_UNSIGNED_BYTE, atlas.memory);
free(atlas.memory);
free(ttf_blob);
return font;
failed:
free(atlas.memory);
free(ttf_blob);
font_del(font);
return NULL;
}
static void
draw_line(float x0, float y0, float x1, float y1, const gui_byte *c)
{
glColor4ub(c[0], c[1], c[2], c[3]);
glBegin(GL_LINES);
glVertex2f(x0, y0);
glVertex2f(x1, y1);
glEnd();
}
static void
draw_rect(float x, float y, float w, float h, const gui_byte *c)
{
glColor4ub(c[0], c[1], c[2], c[3]);
glBegin(GL_QUADS);
glVertex2f(x, y);
glVertex2f(x + w, y);
glVertex2f(x + w, y + h);
glVertex2f(x, y + h);
glEnd();
}
static void
draw_circle(float x, float y, float r, const gui_byte *c)
{
int i;
float a0 = 0.0f;
const float a_step = (2 * 3.141592654f)/22.0f;
x += r; y += r;
glColor4ub(c[0], c[1], c[2], c[3]);
glBegin(GL_TRIANGLES);
for (i = 0; i < CIRCLE_SEGMENTS; i++) {
const float a1 = ((i + 1) == CIRCLE_SEGMENTS) ? 0.0f : a0 + a_step;
const float p0x = x + (float)cos(a0) * r;
const float p0y = y + (float)sin(a0) * r;
const float p1x = x + (float)cos(a1) * r;
const float p1y = y + (float)sin(a1) * r;
glVertex2f(p0x, p0y);
glVertex2f(p1x, p1y);
glVertex2f(x, y);
a0 = a1;
}
glEnd();
}
static void
execute(struct gui_command_buffer *list, int width, int height)
{
const struct gui_command *cmd;
glPushAttrib(GL_ENABLE_BIT|GL_COLOR_BUFFER_BIT|GL_TRANSFORM_BIT);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glDisable(GL_CULL_FACE);
glDisable(GL_DEPTH_TEST);
glEnable(GL_SCISSOR_TEST);
glEnable(GL_TEXTURE_2D);
glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glOrtho(0.0f, width, height, 0.0f, 0.0f, 1.0f);
glMatrixMode(GL_MODELVIEW);
glPushMatrix();
glLoadIdentity();
gui_foreach_command(cmd, list) {
switch (cmd->type) {
case GUI_COMMAND_NOP: break;
case GUI_COMMAND_SCISSOR: {
const struct gui_command_scissor *s = gui_command(scissor, cmd);
glScissor(s->x, height - (s->y + s->h), s->w, s->h);
} break;
case GUI_COMMAND_LINE: {
const struct gui_command_line *l = gui_command(line, cmd);
draw_line(l->begin[0], l->begin[1], l->end[0], l->end[1], l->color);
} break;
case GUI_COMMAND_RECT: {
const struct gui_command_rect *r = gui_command(rect, cmd);
draw_rect(r->x, r->y, r->w, r->h, r->color);
} break;
case GUI_COMMAND_CIRCLE: {
const struct gui_command_circle *c = gui_command(circle, cmd);
draw_circle(c->x, c->y, (float)c->w / 2.0f, c->color);
} break;
case GUI_COMMAND_TRIANGLE: {
const struct gui_command_triangle *t = gui_command(triangle, cmd);
glColor4ub(t->color[0], t->color[1], t->color[2], t->color[3]);
glBegin(GL_TRIANGLES);
glVertex2f(t->a[0], t->a[1]);
glVertex2f(t->b[0], t->b[1]);
glVertex2f(t->c[0], t->c[1]);
glEnd();
} break;
case GUI_COMMAND_TEXT: {
const struct gui_command_text *t = gui_command(text, cmd);
font_draw_text(t->font.ptr, t->x, t->y, t->h, t->fg, t->string, t->length);
} break;
case GUI_COMMAND_IMAGE:
case GUI_COMMAND_MAX:
default: break;
}
}
glBindTexture(GL_TEXTURE_2D, 0);
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glPopAttrib();
}
static void
draw(struct gui_stack *stack, int width, int height)
{
struct gui_panel*iter;
gui_foreach_panel(iter, stack)
execute(iter->buffer, width, height);
}
static void
key(struct gui_input *in, SDL_Event *evt, gui_bool down)
{
SDL_Keycode sym = evt->key.keysym.sym;
if (sym == SDLK_RSHIFT || sym == SDLK_LSHIFT)
gui_input_key(in, GUI_KEY_SHIFT, down);
else if (sym == SDLK_DELETE)
gui_input_key(in, GUI_KEY_DEL, down);
else if (sym == SDLK_RETURN)
gui_input_key(in, GUI_KEY_ENTER, down);
else if (sym == SDLK_SPACE)
gui_input_key(in, GUI_KEY_SPACE, down);
else if (sym == SDLK_BACKSPACE)
gui_input_key(in, GUI_KEY_BACKSPACE, down);
}
static void
motion(struct gui_input *in, SDL_Event *evt)
{
const gui_int x = evt->motion.x;
const gui_int y = evt->motion.y;
gui_input_motion(in, x, y);
}
static void
btn(struct gui_input *in, SDL_Event *evt, gui_bool down)
{
const gui_int x = evt->button.x;
const gui_int y = evt->button.y;
if (evt->button.button == SDL_BUTTON_LEFT)
gui_input_button(in, x, y, down);
}
static void
text(struct gui_input *in, SDL_Event *evt)
{
gui_glyph glyph;
memcpy(glyph, evt->text.text, GUI_UTF_SIZE);
gui_input_glyph(in, glyph);
}
static void
resize(SDL_Event *evt)
{
if (evt->window.event != SDL_WINDOWEVENT_RESIZED) return;
glViewport(0, 0, evt->window.data1, evt->window.data2);
}
int
main(int argc, char *argv[])
{
/* Platform */
const char *font_path;
SDL_Window *win;
SDL_GLContext glContext;
struct font *glfont;
int win_width, win_height;
unsigned int started;
unsigned int dt;
int width = 0, height = 0;
/* GUI */
struct gui_input in;
struct gui_font font;
struct demo_gui gui;
font_path = argv[1];
if (argc < 2) {
fprintf(stdout, "Missing TTF Font file argument!");
exit(EXIT_FAILURE);
}
/* SDL */
SDL_Init(SDL_INIT_VIDEO|SDL_INIT_TIMER|SDL_INIT_EVENTS);
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
win = SDL_CreateWindow("Demo",
SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
WINDOW_WIDTH, WINDOW_HEIGHT, SDL_WINDOW_OPENGL|SDL_WINDOW_SHOWN);
glContext = SDL_GL_CreateContext(win);
SDL_GetWindowSize(win, &win_width, &win_height);
glViewport(0, 0, WINDOW_WIDTH, WINDOW_HEIGHT);
glfont = font_new(font_path, 10, 10, 255, FONT_ATLAS_DIM_256);
/* GUI */
memset(&in, 0, sizeof in);
memset(&gui, 0, sizeof gui);
gui.memory = malloc(MAX_MEMORY);
font.userdata.ptr = glfont;
font.height = glfont->height;
font.width = font_get_text_width;
init_demo(&gui, &font);
while (gui.running) {
/* Input */
SDL_Event evt;
started = SDL_GetTicks();
gui_input_begin(&in);
while (SDL_PollEvent(&evt)) {
if (evt.type == SDL_WINDOWEVENT) resize(&evt);
else if (evt.type == SDL_QUIT) goto cleanup;
else if (evt.type == SDL_KEYUP) key(&in, &evt, gui_false);
else if (evt.type == SDL_KEYDOWN) key(&in, &evt, gui_true);
else if (evt.type == SDL_MOUSEBUTTONDOWN) btn(&in, &evt, gui_true);
else if (evt.type == SDL_MOUSEBUTTONUP) btn(&in, &evt, gui_false);
else if (evt.type == SDL_MOUSEMOTION) motion(&in, &evt);
else if (evt.type == SDL_TEXTINPUT) text(&in, &evt);
else if (evt.type == SDL_MOUSEWHEEL) gui_input_scroll(&in, (float)evt.wheel.y);
}
gui_input_end(&in);
/* GUI */
SDL_GetWindowSize(win, &width, &height);
run_demo(&gui, &in);
/* Draw */
glClearColor(0.4f, 0.4f, 0.4f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
draw(&gui.stack, width, height);
SDL_GL_SwapWindow(win);
/* Timing */
dt = SDL_GetTicks() - started;
gui.ms = dt;
if (dt < DTIME)
SDL_Delay(DTIME - dt);
}
cleanup:
/* Cleanup */
free(gui.memory);
font_del(glfont);
SDL_GL_DeleteContext(glContext);
SDL_DestroyWindow(win);
SDL_Quit();
return 0;
}
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