glsl_blur

bool HelloWorld::init() {

if(!Layer::init()) {

    return false;

}

    Sprite* sprite_blur = Sprite::create("checkbox_checked.png");

    GLchar * fragSource = nullptr;

   

    fragSource = (GLchar*)String::createWithContentsOfFile(FileUtils::getInstance()->fullPathForFilename("blur.fsh").c_str())->getCString();

    sprite_blur->setShaderProgram(GLProgram::createWithByteArrays(ccPositionTextureColor_noMVP_vert, fragSource));

    sprite_blur->setGLProgramState(GLProgramState::getOrCreateWithGLProgram(sprite_blur->getGLProgram()));

    sprite_blur->getGLProgramState()->setUniformVec2("resolution", sprite_blur->getTexture()->getContentSizeInPixels());

    sprite_blur->getGLProgramState()->setUniformFloat("blurRadius", 10.0f);

    sprite_blur->getGLProgramState()->setUniformFloat("sampleNum", 7.0f);

    sprite_blur->setPosition(400, 400);

    addChild(sprite_blur);

//==blur.fsh==

#ifdef GL_ES

precision mediump float;

#endif

varying vec4 v_fragmentColor;

varying vec2 v_texCoord;

uniform vec2 resolution;

uniform float blurRadius;

uniform float sampleNum;

vec4 blur(vec2);

void main(void)

{

   vec4 col = blur(v_texCoord); //* v_fragmentColor.rgb;

   gl_FragColor = vec4(col) * v_fragmentColor;

}

vec4 blur(vec2 p)

{

   if (blurRadius > 0.0 && sampleNum > 1.0)

   {

       vec4 col = vec4(0);

       vec2 unit = 1.0 / resolution.xy;

       

       float r = blurRadius;

       float sampleStep = r / sampleNum;

       

       float count = 0.0;

       

       for(float x = -r; x < r; x += sampleStep)

       {

           for(float y = -r; y < r; y += sampleStep)

           {

               float weight = (r - abs(x)) * (r - abs(y));

               col += texture2D(CC_Texture0, p + vec2(x * unit.x, y * unit.y)) * weight;

               count += weight;

           }

       }

       

       return col / count;

   }

   

   return texture2D(CC_Texture0, p);

}