cocos2dx源码分析：Texture2d创建
cocos2dx中Texture2d代表gpu中的一张纹理，它的数据一般来自于磁盘上的图片，Image从磁盘读取图片数据，然后用这些数据初始化一个Texture2d对象。
bool Texture2D::initWithImage(Image *image, PixelFormat format)
{
if (image == nullptr)
{
CCLOG("cocos2d: Texture2D. Can't create Texture. UIImage is nil");
return false;
}
/*获取图片信息，宽高等*/
int imageWidth = image->getWidth();
int imageHeight = image->getHeight();
this->_filePath = image->getFilePath();
Configuration *conf = Configuration::getInstance();
int maxTextureSize = conf->getMaxTextureSize();
/*opengles对图片尺寸有限制，不能超过最大尺寸限制*/
if (imageWidth > maxTextureSize || imageHeight > maxTextureSize)
{
CCLOG("cocos2d: WARNING: Image (%u x %u) is bigger than the supported %u x %u", imageWidth, imageHeight, maxTextureSize, maxTextureSize);
return false;
}
/*获取图片数据和像素格式*/
unsigned char* tempData = image->getData();
Size imageSize = Size((float)imageWidth, (float)imageHeight);
PixelFormat pixelFormat = ((PixelFormat::NONE == format) || (PixelFormat::AUTO == format)) ? image->getRenderFormat() : format;
PixelFormat renderFormat = image->getRenderFormat();
size_t tempDataLen = image->getDataLen();
if (image->getNumberOfMipmaps() > 1)
{
if (pixelFormat != image->getRenderFormat())
{
CCLOG("cocos2d: WARNING: This image has more than 1 mipmaps and we will not convert the data format");
}
/*初始化带mipmaps的Texture2d*/
initWithMipmaps(image->getMipmaps(), image->getNumberOfMipmaps(), image->getRenderFormat(), imageWidth, imageHeight);
// set the premultiplied tag
_hasPremultipliedAlpha = image->hasPremultipliedAlpha();
return true;
}
else if (image->isCompressed())
{
if (pixelFormat != image->getRenderFormat())
{
CCLOG("cocos2d: WARNING: This image is compressed and we cann't convert it for now");
}
/*用压缩数据初始化的Texture2d*/
initWithData(tempData, tempDataLen, image->getRenderFormat(), imageWidth, imageHeight, imageSize);
// set the premultiplied tag
_hasPremultipliedAlpha = image->hasPremultipliedAlpha();
return true;
}
else
{
unsigned char* outTempData = nullptr;
ssize_t outTempDataLen = 0;
pixelFormat = convertDataToFormat(tempData, tempDataLen, renderFormat, pixelFormat, &outTempData, &outTempDataLen);
/*一般初始化过程*/
initWithData(outTempData, outTempDataLen, pixelFormat, imageWidth, imageHeight, imageSize);
if (outTempData != nullptr && outTempData != tempData)
{
free(outTempData);
}
// set the premultiplied tag
_hasPremultipliedAlpha = image->hasPremultipliedAlpha();
return true;
}
}bool Texture2D::initWithMipmaps(MipmapInfo* mipmaps, int mipmapsNum, PixelFormat pixelFormat, int pixelsWide, int pixelsHigh)
{
//the pixelFormat must be a certain value
CCASSERT(pixelFormat != PixelFormat::NONE && pixelFormat != PixelFormat::AUTO, "the \"pixelFormat\" param must be a certain value!");
CCASSERT(pixelsWide>0 && pixelsHigh>0, "Invalid size");
/*mipmapsNum至少有一个主纹理*/
if (mipmapsNum <= 0)
{
CCLOG("cocos2d: WARNING: mipmap number is less than 1");
return false;
}
/*检查是否是可识别的图片格式*/
if(_pixelFormatInfoTables.find(pixelFormat) == _pixelFormatInfoTables.end())
{
CCLOG("cocos2d: WARNING: unsupported pixelformat: %lx", (unsigned long)pixelFormat );
return false;
}
const PixelFormatInfo& info = _pixelFormatInfoTables.at(pixelFormat);
/*判断是否支持压缩*/
if (info.compressed && !Configuration::getInstance()->supportsPVRTC() && !Configuration::getInstance()->supportsETC() && !Configuration::getInstance()->supportsS3TC() && !Configuration::getInstance()->supportsATITC()) { CCLOG("cocos2d: WARNING: PVRTC/ETC images are not supported"); return false; } /*当创建纹理对象时，设置发往gpu的数据打包格式*/ //Set the row align only when mipmapsNum == 1 and the data is uncompressed if (mipmapsNum == 1 && !info.compressed) { unsigned int bytesPerRow = pixelsWide * info.bpp / 8; if(bytesPerRow % 8 == 0) { glPixelStorei(GL_UNPACK_ALIGNMENT, 8); } else if(bytesPerRow % 4 == 0) { glPixelStorei(GL_UNPACK_ALIGNMENT, 4); } else if(bytesPerRow % 2 == 0) { glPixelStorei(GL_UNPACK_ALIGNMENT, 2); } else { glPixelStorei(GL_UNPACK_ALIGNMENT, 1); } }else { glPixelStorei(GL_UNPACK_ALIGNMENT, 1); } if(_name != 0) { GL::deleteTexture(_name); _name = 0; } /*生成纹理对象*/ glGenTextures(1, &_name); GL::bindTexture2D(_name); /*设置纹理过滤方式*/ if (mipmapsNum == 1) { glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, _antialiasEnabled ? GL_LINEAR : GL_NEAREST); }else { glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, _antialiasEnabled ? GL_LINEAR_MIPMAP_NEAREST : GL_NEAREST_MIPMAP_NEAREST); } glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, _antialiasEnabled ? GL_LINEAR : GL_NEAREST ); /*设置纹理寻址模式*/ glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE ); glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE ); #if CC_ENABLE_CACHE_TEXTURE_DATA if (_antialiasEnabled) { TexParams texParams = {(GLuint)(_hasMipmaps?GL_LINEAR_MIPMAP_NEAREST:GL_LINEAR),GL_LINEAR,GL_NONE,GL_NONE}; VolatileTextureMgr::setTexParameters(this, texParams); } else { TexParams texParams = {(GLuint)(_hasMipmaps?GL_NEAREST_MIPMAP_NEAREST:GL_NEAREST),GL_NEAREST,GL_NONE,GL_NONE}; VolatileTextureMgr::setTexParameters(this, texParams); } #endif // clean possible GL error GLenum err = glGetError(); if (err != GL_NO_ERROR) { cocos2d::log("OpenGL error 0x%04X in %s %s %d\n", err, __FILE__, __FUNCTION__, __LINE__); } // Specify OpenGL texture image int width = pixelsWide; int height = pixelsHigh; /*创建纹理对象数据*/ for (int i = 0; i < mipmapsNum; ++i) { unsigned char *data = mipmaps[i].address; GLsizei datalen = mipmaps[i].len; if (info.compressed) { glCompressedTexImage2D(GL_TEXTURE_2D, i, info.internalFormat, (GLsizei)width, (GLsizei)height, 0, datalen, data); } else { glTexImage2D(GL_TEXTURE_2D, i, info.internalFormat, (GLsizei)width, (GLsizei)height, 0, info.format, info.type, data); } if (i > 0 && (width != height || ccNextPOT(width) != width )) { CCLOG("cocos2d: Texture2D. WARNING. Mipmap level %u is not squared. Texture won't render correctly. width=%d != height=%d", i, width, height); } err = glGetError(); if (err != GL_NO_ERROR) { CCLOG("cocos2d: Texture2D: Error uploading compressed texture level: %u . glError: 0x%04X", i, err); return false; } width = MAX(width >> 1, 1); height = MAX(height >> 1, 1); } /*保存基本数据*/ _contentSize = Size((float)pixelsWide, (float)pixelsHigh); _pixelsWide = pixelsWide; _pixelsHigh = pixelsHigh; _pixelFormat = pixelFormat; _maxS = 1; _maxT = 1; _hasPremultipliedAlpha = false; _hasMipmaps = mipmapsNum > 1; /*Texture2d支持直接进行渲染，这里设置Texture2d的渲染着色器脚本*/ // shader setGLProgram(GLProgramCache::getInstance()->getGLProgram(GLProgram::SHADER_NAME_POSITION_TEXTURE)); return true; }cocos2dx支持的纹理图片像素格式
static const PixelFormatInfoMapValue TexturePixelFormatInfoTablesValue[] =
{
PixelFormatInfoMapValue(Texture2D::PixelFormat::BGRA8888, Texture2D::PixelFormatInfo(GL_BGRA, GL_BGRA, GL_UNSIGNED_BYTE, 32, false, true)),
PixelFormatInfoMapValue(Texture2D::PixelFormat::RGBA8888, Texture2D::PixelFormatInfo(GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE, 32, false, true)),
PixelFormatInfoMapValue(Texture2D::PixelFormat::RGBA4444, Texture2D::PixelFormatInfo(GL_RGBA, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, 16, false, true)),
PixelFormatInfoMapValue(Texture2D::PixelFormat::RGB5A1, Texture2D::PixelFormatInfo(GL_RGBA, GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1, 16, false, true)),
PixelFormatInfoMapValue(Texture2D::PixelFormat::RGB565, Texture2D::PixelFormatInfo(GL_RGB, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, 16, false, false)),
PixelFormatInfoMapValue(Texture2D::PixelFormat::RGB888, Texture2D::PixelFormatInfo(GL_RGB, GL_RGB, GL_UNSIGNED_BYTE, 24, false, false)),
PixelFormatInfoMapValue(Texture2D::PixelFormat::A8, Texture2D::PixelFormatInfo(GL_ALPHA, GL_ALPHA, GL_UNSIGNED_BYTE, 8, false, false)),
PixelFormatInfoMapValue(Texture2D::PixelFormat::I8, Texture2D::PixelFormatInfo(GL_LUMINANCE, GL_LUMINANCE, GL_UNSIGNED_BYTE, 8, false, false)),
PixelFormatInfoMapValue(Texture2D::PixelFormat::AI88, Texture2D::PixelFormatInfo(GL_LUMINANCE_ALPHA, GL_LUMINANCE_ALPHA, GL_UNSIGNED_BYTE, 16, false, true)),
#ifdef GL_COMPRESSED_RGB_PVRTC_2BPPV1_IMG
PixelFormatInfoMapValue(Texture2D::PixelFormat::PVRTC2, Texture2D::PixelFormatInfo(GL_COMPRESSED_RGB_PVRTC_2BPPV1_IMG, 0xFFFFFFFF, 0xFFFFFFFF, 2, true, false)),
PixelFormatInfoMapValue(Texture2D::PixelFormat::PVRTC2A, Texture2D::PixelFormatInfo(GL_COMPRESSED_RGBA_PVRTC_2BPPV1_IMG, 0xFFFFFFFF, 0xFFFFFFFF, 2, true, true)),
PixelFormatInfoMapValue(Texture2D::PixelFormat::PVRTC4, Texture2D::PixelFormatInfo(GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG, 0xFFFFFFFF, 0xFFFFFFFF, 4, true, false)),
PixelFormatInfoMapValue(Texture2D::PixelFormat::PVRTC4A, Texture2D::PixelFormatInfo(GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG, 0xFFFFFFFF, 0xFFFFFFFF, 4, true, true)),
#endif
#ifdef GL_ETC1_RGB8_OES
PixelFormatInfoMapValue(Texture2D::PixelFormat::ETC, Texture2D::PixelFormatInfo(GL_ETC1_RGB8_OES, 0xFFFFFFFF, 0xFFFFFFFF, 4, true, false)),
#endif
#ifdef GL_COMPRESSED_RGBA_S3TC_DXT1_EXT
PixelFormatInfoMapValue(Texture2D::PixelFormat::S3TC_DXT1, Texture2D::PixelFormatInfo(GL_COMPRESSED_RGBA_S3TC_DXT1_EXT, 0xFFFFFFFF, 0xFFFFFFFF, 4, true, false)),
#endif
#ifdef GL_COMPRESSED_RGBA_S3TC_DXT3_EXT
PixelFormatInfoMapValue(Texture2D::PixelFormat::S3TC_DXT3, Texture2D::PixelFormatInfo(GL_COMPRESSED_RGBA_S3TC_DXT3_EXT, 0xFFFFFFFF, 0xFFFFFFFF, 8, true, false)),
#endif
#ifdef GL_COMPRESSED_RGBA_S3TC_DXT5_EXT
PixelFormatInfoMapValue(Texture2D::PixelFormat::S3TC_DXT5, Texture2D::PixelFormatInfo(GL_COMPRESSED_RGBA_S3TC_DXT5_EXT, 0xFFFFFFFF, 0xFFFFFFFF, 8, true, false)),
#endif
#ifdef GL_ATC_RGB_AMD
PixelFormatInfoMapValue(Texture2D::PixelFormat::ATC_RGB, Texture2D::PixelFormatInfo(GL_ATC_RGB_AMD,
0xFFFFFFFF, 0xFFFFFFFF, 4, true, false)),
#endif
#ifdef GL_ATC_RGBA_EXPLICIT_ALPHA_AMD
PixelFormatInfoMapValue(Texture2D::PixelFormat::ATC_EXPLICIT_ALPHA, Texture2D::PixelFormatInfo(GL_ATC_RGBA_EXPLICIT_ALPHA_AMD,
0xFFFFFFFF, 0xFFFFFFFF, 8, true, false)),
#endif
#ifdef GL_ATC_RGBA_INTERPOLATED_ALPHA_AMD
PixelFormatInfoMapValue(Texture2D::PixelFormat::ATC_INTERPOLATED_ALPHA, Texture2D::PixelFormatInfo(GL_ATC_RGBA_INTERPOLATED_ALPHA_AMD,
0xFFFFFFFF, 0xFFFFFFFF, 8, true, false)),
#endif
};