func (t *Texture) ReadTextureFromGPU() []byte {
t.Bind()
b := gl.GenBuffer()
b.Bind(gl.PIXEL_UNPACK_BUFFER)
gl.BufferData(gl.PIXEL_UNPACK_BUFFER, t.Width()*t.Height()*t.PixelSize(), 0, gl.STREAM_DRAW)
//gl.GetTexImage(t.target, 0, t.format, buffer)
b.Bind(gl.PIXEL_UNPACK_BUFFER)
gl.TexSubImage2D(t.target, 0, 0, 0, t.Width(), t.Height(), t.format, t.typ, unsafe.Pointer(uintptr(0)))
b.Bind(gl.PIXEL_UNPACK_BUFFER)
l := t.Width() * t.Height() * t.PixelSize()
gl.BufferData(gl.PIXEL_UNPACK_BUFFER, t.Width()*t.Height()*t.PixelSize(), 0, gl.STREAM_DRAW)
ptr := gl.MapBuffer(gl.PIXEL_UNPACK_BUFFER, gl.WRITE_ONLY)
var x []byte
s := (*reflect.SliceHeader)(unsafe.Pointer(&x))
s.Data = uintptr(ptr)
s.Len = l
s.Cap = l
gl.UnmapBuffer(gl.PIXEL_UNPACK_BUFFER)
return x
}
func HeightMapUpdate(loc *renderstuff.RenderLocations, entity renderstuff.IRenderEntity, etc interface{}) {
heightMap := entity.(*gamestate.HeightMap)
if heightMap.HasChanges {
min_h, max_h := heightMap.Bounds()
loc.LowerBound.Uniform3f(0, 0, min_h)
loc.UpperBound.Uniform3f(float32(heightMap.W), float32(heightMap.H), max_h)
gl.ActiveTexture(gl.TEXTURE0 + constants.TextureHeightMap)
gl.TexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, heightMap.W, heightMap.H, gl.RED, gl.FLOAT, heightMap.TexturePixels())
gl.ActiveTexture(gl.TEXTURE0)
heightMap.HasChanges = false
}
}