图片灰化处理办法之shader篇
1、写好一个图像变灰的shader程序,并放入到cocos2dx引擎下面的shader文件夹中。
" \n\
#ifdef GL_ES \n\
precision mediump float; \n\
#endif \n\
\n\
uniform sampler2D u_texture; \n\
varying vec2 v_texCoord; \n\
varying vec4 v_fragmentColor; \n\
\n\
void main(void) \n\
{ \n\
// Convert to greyscale using NTSC weightings \n\
vec4 col = texture2D(u_texture, v_texCoord); \n\
float grey = dot(col.rgb, vec3(0.299, 0.587, 0.114)); \n\
gl_FragColor = vec4(grey, grey, grey, col.a); \n\
} \n\
";
2、ccShaders.h中添加
extern CC_DLL const GLchar * ccPositionTextureGray_frag; |
3、ccShaders.cpp中添加
const GLchar * ccPositionTextureGray_frag =
#include "ccShader_PositionTextureGray_frag.h"
4、CCGLProgram.h中添加
#define kCCShader_PositionTextureGray "ShaderPositionTextureGray"
5、CCShaderCache.cpp中添加枚举类型
kCCShaderType_PositionTextureGray,
CCShaderCache::loadDefaultShaders()中添加
// Position Texture Gray shader
p = new CCGLProgram();
loadDefaultShader(p, kCCShaderType_PositionTextureGray);
m_pPrograms->setObject(p, kCCShader_PositionTextureGray);
p->release();
CCShaderCache::reloadDefaultShaders()中添加
// Position Texture Gray shader
p = programForKey(kCCShader_PositionTextureGray);
p->reset();
loadDefaultShader(p, kCCShaderType_PositionTextureGray);
CCShaderCache::loadDefaultShader(CCGLProgram *p, int type)中添加
casekCCShaderType_PositionTextureGray:
p->initWithVertexShaderByteArray(ccPositionTextureColor_vert, ccPositionTextureGray_frag);
p->addAttribute(kCCAttributeNamePosition, kCCVertexAttrib_Position);
p->addAttribute(kCCAttributeNameColor, kCCVertexAttrib_Color);
p->addAttribute(kCCAttributeNameTexCoord, kCCVertexAttrib_TexCoords);
break;
6、新建一个灰度转换调用类(以便扩展其他的颜色转换)
//ColorUtils.h
#include "cocos2d.h"
USING_NS_CC;
class ColorUtils
{
public:
ColorUtils();
~ColorUtils();
static void AddColorGray(CCSprite * spr);
static void RemoveColorGray(CCSprite * spr);
private:
};
//ColorUtils.cpp
#include "ColorUtils.h"
ColorUtils::ColorUtils()
{
}
ColorUtils::~ColorUtils()
{
}
void ColorUtils::AddColorGray(CCSprite * spr)
{
spr->setShaderProgram(CCShaderCache::sharedShaderCache()->programForKey(kCCShader_PositionTextureGray));
}
void ColorUtils::RemoveColorGray(CCSprite * spr)
{
spr->setShaderProgram(CCShaderCache::sharedShaderCache()->programForKey(kCCShader_PositionTextureColor));
}