片元着色器:
out vec4 Color;
uniform samplerBuffer sampler;
uniform int index;
void main()
{
Color=normalize(texelFetch(sampler,index));
}
我正在使用glTexBuffer()将所有内部格式用于纹理渲染,这些格式在http://www.opengl.org/sdk/docs/man3/xhtml/glTexBuffer.xml上都有说明。上述着色器仅适用于ubyte、ushort归一化类型和float、halffloat非归一化类型。对于其余的内部格式,它不会在几何图形上应用纹理。
我需要改变什么才能得到所需的效果?
代码:
GLbyte arr[]={124,5,126};
glGenBuffers(1,&bufferid);
glBindBuffer(GL_TEXTURE_BUFFER,bufferid);
glBufferData(GL_TEXTURE_BUFFER,sizeof(arr),arr,GL_STATIC_DRAW);
glGenTextures(1, &buffer_texture);
glBindTexture(GL_TEXTURE_BUFFER, buffer_texture);
glTexBuffer(GL_TEXTURE_BUFFER, GL_R8I, bufferid);
glUniform1i(glGetUniformLocation(shader_data.psId,"sampler"),0);
glUniform1i(glGetUniformLocation(shader_data.psId,"index"),0);
glGenBuffers(1,&bufferid1);
glBindBuffer(GL_ARRAY_BUFFER,bufferid1);
glBufferData(GL_ARRAY_BUFFER,sizeof(vertices4),vertices4,GL_STATIC_DRAW);
attr_vertex = glGetAttribLocation(shader_data.psId, "a_position");
glVertexAttribPointer(attr_vertex, 2 , GL_FLOAT, GL_FALSE ,0, 0);
glEnableVertexAttribArray(attr_vertex);
glDrawArrays(GL_TRIANGLE_FAN,0,4);
glUniform1i(glGetUniformLocation(shader_data.psId,"index"),1);
glVertexAttribPointer(attr_vertex, 2 , GL_FLOAT, GL_FALSE ,0,(void *)(32) );
glDrawArrays(GL_TRIANGLE_FAN,0,4);
glUniform1i(glGetUniformLocation(shader_data.psId,"index"),2);
glVertexAttribPointer(attr_vertex, 2 , GL_FLOAT, GL_FALSE ,0,(void *)(64) );
glDrawArrays(GL_TRIANGLE_FAN,0,4);
我必须使用所有内部格式来应用纹理。