func NewLightPass(input *render.GeometryBuffer) *LightPass {
shadowPass := NewShadowPass(input)
/* use a virtual material to help with vertex attributes and textures */
mat := render.CreateMaterial(render.CompileVFShader("/assets/shaders/voxel_light_pass"))
/* we're going to render a simple quad, so we input
* position and texture coordinates */
mat.AddDescriptor("position", gl.FLOAT, 3, 20, 0, false, false)
mat.AddDescriptor("texcoord", gl.FLOAT, 2, 20, 12, false, false)
/* the shader uses 3 textures from the geometry frame buffer.
* they are previously rendered in the geometry pass. */
mat.AddTexture("tex_diffuse", input.Diffuse)
mat.AddTexture("tex_normal", input.Normal)
mat.AddTexture("tex_depth", input.Depth)
mat.AddTexture("tex_shadow", shadowPass.Output)
/* create a render quad */
quad := render.NewRenderQuad()
/* set up vertex attribute pointers */
mat.SetupVertexPointers()
p := &LightPass{
Material: mat,
quad: quad,
Shadows: shadowPass,
}
return p
}
func GetShader(name string) *render.ShaderProgram {
// check shader cache
if shader, exists := cache.Shaders[name]; exists {
fmt.Println("Shader cache hit", name)
return shader
}
// attempt to load
fmt.Println("Loading shader", name)
shader := render.CompileVFShader("assets/shaders/" + name)
cache.Shaders[name] = shader
return shader
}