bgfx/examples/common/cube_atlas.cpp

489 lines
14 KiB
C++

/* Copyright 2013 Jeremie Roy. All rights reserved.
* License: http://www.opensource.org/licenses/BSD-2-Clause
*/
#pragma once
#include "cube_atlas.h"
#include <bx/bx.h>
#include <bgfx.h>
#include <vector>
//********** Rectangle packer implementation ************
class RectanglePacker
{
public:
RectanglePacker();
RectanglePacker(uint32_t _width, uint32_t _height);
/// non constructor initialization
void init(uint32_t _width, uint32_t _height);
/// find a suitable position for the given rectangle
/// @return true if the rectangle can be added, false otherwise
bool addRectangle(uint16_t _width, uint16_t _height, uint16_t& _outX, uint16_t& _outY );
/// return the used surface in squared unit
uint32_t getUsedSurface() { return m_usedSpace; }
/// return the total available surface in squared unit
uint32_t getTotalSurface() { return m_width*m_height; }
/// return the usage ratio of the available surface [0:1]
float getUsageRatio();
/// reset to initial state
void clear();
private:
int32_t fit(uint32_t _skylineNodeIndex, uint16_t _width, uint16_t _height);
/// Merges all skyline nodes that are at the same level.
void merge();
struct Node
{
Node(int16_t _x, int16_t _y, int16_t _width):m_x(_x), m_y(_y), m_width(_width) {}
/// The starting x-coordinate (leftmost).
int16_t m_x;
/// The y-coordinate of the skyline level line.
int16_t m_y;
/// The line _width. The ending coordinate (inclusive) will be x+width-1.
int32_t m_width; //32bit to avoid padding
};
/// width (in pixels) of the underlying texture
uint32_t m_width;
/// height (in pixels) of the underlying texture
uint32_t m_height;
/// Surface used in squared pixel
uint32_t m_usedSpace;
/// node of the skyline algorithm
std::vector<Node> m_skyline;
};
RectanglePacker::RectanglePacker(): m_width(0), m_height(0), m_usedSpace(0)
{
}
RectanglePacker::RectanglePacker(uint32_t _width, uint32_t _height):m_width(_width), m_height(_height), m_usedSpace(0)
{
// We want a one pixel border around the whole atlas to avoid any artefact when
// sampling texture
m_skyline.push_back(Node(1,1, _width-2));
}
void RectanglePacker::init(uint32_t _width, uint32_t _height)
{
BX_CHECK(_width > 2, "_width must be > 2");
BX_CHECK(_height > 2, "_height must be > 2");
m_width = _width;
m_height = _height;
m_usedSpace = 0;
m_skyline.clear();
// We want a one pixel border around the whole atlas to avoid any artifact when
// sampling texture
m_skyline.push_back(Node(1,1, _width-2));
}
bool RectanglePacker::addRectangle(uint16_t _width, uint16_t _height, uint16_t& _outX, uint16_t& _outY)
{
int y, best_height, best_index;
int32_t best_width;
Node* node;
Node* prev;
_outX = 0;
_outY = 0;
uint32_t ii;
best_height = INT_MAX;
best_index = -1;
best_width = INT_MAX;
for( ii = 0; ii < m_skyline.size(); ++ii )
{
y = fit( ii, _width, _height );
if( y >= 0 )
{
node = &m_skyline[ii];
if( ( (y + _height) < best_height ) ||
( ((y + _height) == best_height) && (node->m_width < best_width)) )
{
best_height = y + _height;
best_index = ii;
best_width = node->m_width;
_outX = node->m_x;
_outY = y;
}
}
}
if( best_index == -1 )
{
return false;
}
Node newNode(_outX, _outY + _height, _width);
m_skyline.insert(m_skyline.begin() + best_index, newNode);
for(ii = best_index+1; ii < m_skyline.size(); ++ii)
{
node = &m_skyline[ii];
prev = &m_skyline[ii-1];
if (node->m_x < (prev->m_x + prev->m_width) )
{
int shrink = prev->m_x + prev->m_width - node->m_x;
node->m_x += shrink;
node->m_width -= shrink;
if (node->m_width <= 0)
{
m_skyline.erase(m_skyline.begin() + ii);
--ii;
}
else
{
break;
}
}
else
{
break;
}
}
merge();
m_usedSpace += _width * _height;
return true;
}
float RectanglePacker::getUsageRatio()
{
uint32_t total = m_width*m_height;
if(total > 0)
return (float) m_usedSpace / (float) total;
else
return 0.0f;
}
void RectanglePacker::clear()
{
m_skyline.clear();
m_usedSpace = 0;
// We want a one pixel border around the whole atlas to avoid any artefact when
// sampling texture
m_skyline.push_back(Node(1,1, m_width-2));
}
int32_t RectanglePacker::fit(uint32_t _skylineNodeIndex, uint16_t _width, uint16_t _height)
{
int32_t width = _width;
int32_t height = _height;
const Node& baseNode = m_skyline[_skylineNodeIndex];
int32_t x = baseNode.m_x, y;
int32_t _width_left = width;
int32_t i = _skylineNodeIndex;
if ( (x + width) > (int32_t)(m_width-1) )
{
return -1;
}
y = baseNode.m_y;
while( _width_left > 0 )
{
const Node& node = m_skyline[i];
if( node.m_y > y )
{
y = node.m_y;
}
if( (y + height) > (int32_t)(m_height-1) )
{
return -1;
}
_width_left -= node.m_width;
++i;
}
return y;
}
void RectanglePacker::merge()
{
Node* node;
Node* next;
uint32_t ii;
for( ii=0; ii < m_skyline.size()-1; ++ii )
{
node = (Node *) &m_skyline[ii];
next = (Node *) &m_skyline[ii+1];
if( node->m_y == next->m_y )
{
node->m_width += next->m_width;
m_skyline.erase(m_skyline.begin() + ii + 1);
--ii;
}
}
}
//********** Cube Atlas implementation ************
struct Atlas::PackedLayer
{
RectanglePacker packer;
AtlasRegion faceRegion;
};
Atlas::Atlas(uint16_t _textureSize, uint16_t _maxRegionsCount )
{
BX_CHECK(_textureSize >= 64 && _textureSize <= 4096, "suspicious texture size" );
BX_CHECK(_maxRegionsCount >= 64 && _maxRegionsCount <= 32000, "suspicious _regions count" );
m_layers = new PackedLayer[24];
for(int ii=0; ii<24;++ii)
{
m_layers[ii].packer.init(_textureSize, _textureSize);
}
m_usedLayers = 0;
m_usedFaces = 0;
m_textureSize = _textureSize;
m_regionCount = 0;
m_maxRegionCount = _maxRegionsCount;
m_regions = new AtlasRegion[_maxRegionsCount];
m_textureBuffer = new uint8_t[ _textureSize * _textureSize * 6 * 4 ];
memset(m_textureBuffer, 0, _textureSize * _textureSize * 6 * 4);
//BGFX_TEXTURE_MIN_POINT|BGFX_TEXTURE_MAG_POINT|BGFX_TEXTURE_MIP_POINT;
//BGFX_TEXTURE_MIN_ANISOTROPIC|BGFX_TEXTURE_MAG_ANISOTROPIC|BGFX_TEXTURE_MIP_POINT
//BGFX_TEXTURE_U_CLAMP|BGFX_TEXTURE_V_CLAMP
uint32_t flags = 0;// BGFX_TEXTURE_MIN_ANISOTROPIC|BGFX_TEXTURE_MAG_ANISOTROPIC|BGFX_TEXTURE_MIP_POINT;
//Uncomment this to debug atlas
//const bgfx::Memory* mem = bgfx::alloc(textureSize*textureSize * 6 * 4);
//memset(mem->data, 255, mem->size);
const bgfx::Memory* mem = NULL;
m_textureHandle = bgfx::createTextureCube(6
, _textureSize
, 1
, bgfx::TextureFormat::BGRA8
, flags
,mem
);
}
Atlas::Atlas(uint16_t _textureSize, const uint8_t* _textureBuffer , uint16_t _regionCount, const uint8_t* _regionBuffer, uint16_t _maxRegionsCount)
{
BX_CHECK(_regionCount <= 64 && _maxRegionsCount <= 4096, "suspicious initialization");
//layers are frozen
m_usedLayers = 24;
m_usedFaces = 6;
m_textureSize = _textureSize;
m_regionCount = _regionCount;
//regions are frozen
if(_regionCount < _maxRegionsCount)
m_maxRegionCount = _regionCount;
else
m_maxRegionCount = _maxRegionsCount;
m_regions = new AtlasRegion[_regionCount];
m_textureBuffer = new uint8_t[getTextureBufferSize()];
//BGFX_TEXTURE_MIN_POINT|BGFX_TEXTURE_MAG_POINT|BGFX_TEXTURE_MIP_POINT;
//BGFX_TEXTURE_MIN_ANISOTROPIC|BGFX_TEXTURE_MAG_ANISOTROPIC|BGFX_TEXTURE_MIP_POINT
//BGFX_TEXTURE_U_CLAMP|BGFX_TEXTURE_V_CLAMP
uint32_t flags = 0;//BGFX_TEXTURE_MIN_ANISOTROPIC|BGFX_TEXTURE_MAG_ANISOTROPIC|BGFX_TEXTURE_MIP_POINT;
memcpy(m_regions, _regionBuffer, _regionCount * sizeof(AtlasRegion));
memcpy(m_textureBuffer, _textureBuffer, getTextureBufferSize());
m_textureHandle = bgfx::createTextureCube(6
, _textureSize
, 1
, bgfx::TextureFormat::BGRA8
, flags
, bgfx::makeRef(m_textureBuffer, getTextureBufferSize())
);
}
Atlas::~Atlas()
{
delete[] m_layers;
delete[] m_regions;
delete[] m_textureBuffer;
}
uint16_t Atlas::addRegion(uint16_t _width, uint16_t _height, const uint8_t* _bitmapBuffer, AtlasRegion::Type _type, uint16_t outline)
{
if (m_regionCount >= m_maxRegionCount)
{
return UINT16_MAX;
}
uint16_t x=0,y=0;
// We want each bitmap to be separated by at least one black pixel
// TODO manage mipmaps
uint32_t idx = 0;
while(idx<m_usedLayers)
{
if(m_layers[idx].faceRegion.getType() == _type)
{
if(m_layers[idx].packer.addRectangle(_width+1,_height+1,x,y)) break;
}
idx++;
}
if(idx >= m_usedLayers)
{
//do we have still room to add layers ?
if( (idx + _type) > 24 || m_usedFaces>=6)
{
return UINT16_MAX;
}
//create new layers
for(int ii=0; ii < _type; ++ii)
{
m_layers[idx+ii].faceRegion.setMask(_type, m_usedFaces, ii);
}
m_usedLayers += _type;
m_usedFaces++;
//add it to the created layer
if(!m_layers[idx].packer.addRectangle(_width+1, _height+1, x, y))
{
return UINT16_MAX;
}
}
AtlasRegion& region = m_regions[m_regionCount];
region.m_x = x ;
region.m_y = y ;
region.m_width = _width;
region.m_height = _height;
region.m_mask = m_layers[idx].faceRegion.m_mask;
updateRegion(region, _bitmapBuffer);
region.m_x += outline;
region.m_y += outline;
region.m_width -= (outline*2);
region.m_height -= (outline*2);
return m_regionCount++;
}
void Atlas::updateRegion(const AtlasRegion& _region, const uint8_t* _bitmapBuffer)
{
const bgfx::Memory* mem = bgfx::alloc(_region.m_width * _region.m_height * 4);
//BAD!
memset(mem->data,0, mem->size);
if(_region.getType() == AtlasRegion::TYPE_BGRA8)
{
const uint8_t* inLineBuffer = _bitmapBuffer;
uint8_t* outLineBuffer = m_textureBuffer + _region.getFaceIndex() * (m_textureSize*m_textureSize*4) + (((_region.m_y *m_textureSize)+_region.m_x)*4);
//update the cpu buffer
for(int yy = 0; yy < _region.m_height; ++yy)
{
memcpy(outLineBuffer, inLineBuffer, _region.m_width * 4);
inLineBuffer += _region.m_width*4;
outLineBuffer += m_textureSize*4;
}
//update the GPU buffer
memcpy(mem->data, _bitmapBuffer, mem->size);
}else
{
uint32_t layer = _region.getComponentIndex();
//uint32_t face = _region.getFaceIndex();
const uint8_t* inLineBuffer = _bitmapBuffer;
uint8_t* outLineBuffer = (m_textureBuffer + _region.getFaceIndex() * (m_textureSize*m_textureSize*4) + (((_region.m_y *m_textureSize)+_region.m_x)*4));
//update the cpu buffer
for(int yy = 0; yy<_region.m_height; ++yy)
{
for(int xx = 0; xx<_region.m_width; ++xx)
{
outLineBuffer[(xx*4) + layer] = inLineBuffer[xx];
}
//update the GPU buffer
memcpy(mem->data + yy*_region.m_width*4, outLineBuffer, _region.m_width*4);
inLineBuffer += _region.m_width;
outLineBuffer += m_textureSize*4;
}
}
bgfx::updateTextureCube(m_textureHandle, (uint8_t)_region.getFaceIndex(), 0, _region.m_x, _region.m_y, _region.m_width, _region.m_height, mem);
}
void Atlas::packFaceLayerUV(uint32_t _idx, uint8_t* _vertexBuffer, uint32_t _offset, uint32_t _stride )
{
packUV(m_layers[_idx].faceRegion, _vertexBuffer, _offset, _stride);
}
void Atlas::packUV( uint16_t handle, uint8_t* _vertexBuffer, uint32_t _offset, uint32_t _stride )
{
const AtlasRegion& region = m_regions[handle];
packUV(region, _vertexBuffer, _offset, _stride);
}
void Atlas::packUV( const AtlasRegion& _region, uint8_t* _vertexBuffer, uint32_t _offset, uint32_t _stride )
{
float texMult = 65535.0f / ((float)(m_textureSize));
static const int16_t minVal = -32768;
static const int16_t maxVal = 32767;
int16_t x0 = (int16_t)(_region.m_x * texMult)-32768;
int16_t y0 = (int16_t)(_region.m_y * texMult)-32768;
int16_t x1 = (int16_t)((_region.m_x + _region.m_width)* texMult)-32768;
int16_t y1 = (int16_t)((_region.m_y + _region.m_height)* texMult)-32768;
int16_t w = (int16_t) ((32767.0f/4.0f) * _region.getComponentIndex());
_vertexBuffer+=_offset;
switch(_region.getFaceIndex())
{
case 0: // +X
x0= -x0;
x1= -x1;
y0= -y0;
y1= -y1;
writeUV(_vertexBuffer, maxVal, y0, x0, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, maxVal, y1, x0, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, maxVal, y1, x1, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, maxVal, y0, x1, w); _vertexBuffer+=_stride;
break;
case 1: // -X
y0= -y0;
y1= -y1;
writeUV(_vertexBuffer, minVal, y0, x0, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, minVal, y1, x0, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, minVal, y1, x1, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, minVal, y0, x1, w); _vertexBuffer+=_stride;
break;
case 2: // +Y
writeUV(_vertexBuffer, x0, maxVal, y0, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, x0, maxVal, y1, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, x1, maxVal, y1, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, x1, maxVal, y0, w); _vertexBuffer+=_stride;
break;
case 3: // -Y
y0= -y0;
y1= -y1;
writeUV(_vertexBuffer, x0, minVal, y0, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, x0, minVal, y1, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, x1, minVal, y1, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, x1, minVal, y0, w); _vertexBuffer+=_stride;
break;
case 4: // +Z
y0= -y0;
y1= -y1;
writeUV(_vertexBuffer, x0, y0, maxVal, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, x0, y1, maxVal, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, x1, y1, maxVal, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, x1, y0, maxVal, w); _vertexBuffer+=_stride;
break;
case 5: // -Z
x0= -x0;
x1= -x1;
y0= -y0;
y1= -y1;
writeUV(_vertexBuffer, x0, y0, minVal, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, x0, y1, minVal, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, x1, y1, minVal, w); _vertexBuffer+=_stride;
writeUV(_vertexBuffer, x1, y0, minVal, w); _vertexBuffer+=_stride;
break;
}
}