Uniform Buffer可以以只读方式访问着色器,以便着色器可以读取常量参数数据。
在Vulkan里面,程序员必须自己创建Uniform Buffer,在其他API里面则不需要。
设置Uniform数据
程序可使用Uniform缓冲将MVP(Model-View-Projection)矩阵传入着色器,着色器通过MVP数据对每一个顶点进行变换。
info.Projection = glm::perspective(glm::radians(45.0f), 1.0f, 0.1f, 100.0f);
info.View = glm::lookAt(glm::vec3(-5, 3, -10), // Camera is at (-5,3,-10), in World Space
glm::vec3(0, 0, 0), // and looks at the origin
glm::vec3(0, -1, 0) // Head is up (set to 0,-1,0 to look upside-down)
);
info.Model = glm::mat4(1.0f);
// Vulkan clip space has inverted Y and half Z.
// clang-format off
info.Clip = glm::mat4(1.0f, 0.0f, 0.0f, 0.0f,
0.0f,-1.0f, 0.0f, 0.0f,
0.0f, 0.0f, 0.5f, 0.0f,