draw

Sprite *spriteBack   = m_textureBack->getSprite();
Sprite *spriteFront  = m_textureFront->getSprite();
GLint defFrameBuf    = 0; //デフォルトのFBOを退避
GLuint colorBufBack  = spriteBack->getTexture()->getName();
GLuint colorBufFront = spriteFront->getTexture()->getName();
GLuint frameBufBack = 0, frameBufFront = 0;
glGenFramebuffers(1, &frameBufFront);
glGetIntegerv(GL_FRAMEBUFFER_BINDING, &defFrameBuf);
glBindFramebuffer(GL_FRAMEBUFFER, frameBufFront);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, colorBufFront, 0);
GLenum framebufStatus = glCheckFramebufferStatus(GL_FRAMEBUFFER);
if(framebufStatus != GL_FRAMEBUFFER_COMPLETE){} //error処理

glClearColor(0, 0, 0, 0);
glClear(GL_COLOR_BUFFER_BIT);

//FBOにフレーム内背景を描画
m_programBack->use();
const GLfloat pos[] = { -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f, -1.0f };
glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, (GLvoid*)pos);
glBindTexture(GL_TEXTURE_2D, colorBufBack);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

//FBOにフレーム内前景を描画
DrawProfileCocos2D::preDraw();
m_live2DModel->update();
m_live2DModel->draw();
DrawProfileCocos2D::postDraw();

//サーフェイスにFBOを描画
glBindTexture(GL_TEXTURE_2D, 0);
glBindFramebuffer(GL_FRAMEBUFFER, defFrameBuf);
glDeleteFramebuffers(1, &frameBufFront);
spriteFront->draw(renderer, transform, flags);

fsh

#ifdef GL_ES
precision mediump float;
#endif

uniform vec2  u_center;
uniform float u_width;
varying vec2  v_texCoord;

void main(){
	vec2 pos   = v_texCoord - u_center;
	vec4 color = vec4(0.0);
	int count = 10;
	for(int i = 0; i < count; i++){
		float scale = 1.0 + u_width * (float(i) / float(count - 1));
		color += texture2D(CC_Texture0, pos * scale + u_center);
	}
	gl_FragColor = color / float(count);
}

init

m_programFront = new GLProgram();
m_programFront->retain();
m_textureFront->getSprite()->setGLProgram(m_programFront);
m_programFront->initWithVertexShaderFilename("shaders/radial_blur.vsh","shaders/radial_blur.fsh");
m_programFront->bindAttribLocation(GLProgram::ATTRIBUTE_NAME_POSITION,  GLProgram::VERTEX_ATTRIB_POSITION);
m_programFront->bindAttribLocation(GLProgram::ATTRIBUTE_NAME_TEX_COORD, GLProgram::VERTEX_ATTRIB_TEX_COORDS);
m_programFront->bindAttribLocation(GLProgram::ATTRIBUTE_NAME_COLOR,     GLProgram::VERTEX_ATTRIB_COLOR);
m_programFront->link();
m_programFront->updateUniforms();
//テクスチャサイズ。m_resoScaleは解像度の調整用
m_programFront->setUniformLocationWith2f(m_programFront->getUniformLocationForName("u_size"), width * m_resoScale, height * m_resoScale);
//集中線の中心
m_programFront->setUniformLocationWith2f(m_programFront->getUniformLocationForName("u_center"), 0.5f, 0.5f);
//集中線のサンプリングする幅
m_programFront->setUniformLocationWith1f(m_programFront->getUniformLocationForName("u_width"), -0.1);

vsh

attribute vec4 a_position;
attribute vec2 a_texCoord;
varying vec2   v_texCoord;
  
void main(){
	gl_Position = CC_PMatrix * a_position;
	v_texCoord  = a_texCoord;
}