关于帧缓冲区,我还有些困惑。我的目标是使用一个带有多个纹理附着的帧缓冲区,填充每个纹理,然后使用着色器将所有纹理合并(混合)以创建新的输出。听起来很容易?是的,这就是我想的,但我不太明白。
我该如何将当前绑定的纹理传递给着色器呢?
关于帧缓冲区,我还有些困惑。我的目标是使用一个带有多个纹理附着的帧缓冲区,填充每个纹理,然后使用着色器将所有纹理合并(混合)以创建新的输出。听起来很容易?是的,这就是我想的,但我不太明白。
我该如何将当前绑定的纹理传递给着色器呢?
GLuint frameBuffer;
glGenFramebuffersEXT(1, &frameBuffer); //Create a frame buffer
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, frameBuffer); //Bind it so we draw to it
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, yourTexture, 0); //Attach yourTexture so drawing goes into it
//Draw here and it'll go into yourTexture.
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0); //Unbind the framebuffer so that you can draw normally again
//Here we put the texture in slot 1.
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, yourTexture);
glActiveTexture(GL_TEXTURE0); //Don't forget to go back to GL_TEXTURE0 if you're going to do more drawing later
//Now we tell your shader where to look.
GLint var = glGetUniformLocationARB(yourShaderProgram, "yourSampler");
glUniform1i(var, 1); //We use 1 here because we used GL_TEXTURE1 to bind our texture
在你的片元着色器中:
uniform sampler2D yourSampler;
void main()
{
gl_FragColor = texture2D(yourSampler, whateverCoordinatesYouWant);
}
GL_TEXTURE2
等一起来访问更多纹理。