func uploadTexture_NRGBA32(img *image.NRGBA) gl.Texture {
b := img.Bounds()
data := make([]uint8, b.Max.X*b.Max.Y*4)
for y := 0; y < b.Max.Y; y++ {
for x := 0; x < b.Max.X; x++ {
p := img.At(x, y)
offset := y*b.Max.X*4 + x*4
r, g, b, a := p.RGBA()
data[offset+0] = uint8(r)
data[offset+1] = uint8(g)
data[offset+2] = uint8(b)
data[offset+3] = uint8(a)
}
}
id := gl.GenTexture()
id.Bind(gl.TEXTURE_2D)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_R, gl.CLAMP_TO_EDGE)
gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, b.Max.X, b.Max.Y, 0, gl.RGBA, gl.UNSIGNED_BYTE, data)
if gl.GetError() != gl.NO_ERROR {
id.Delete()
panic(errors.New("Failed to load a texture"))
return 0
}
return id
}
func draw() {
t := float32(sdl.GetTicks()) / 500.0
time := prg.GetUniformLocation("time")
time.Uniform1f(t)
gl.Clear(gl.COLOR_BUFFER_BIT)
gl.DrawArrays(gl.TRIANGLE_STRIP, 0, 4)
if gl.GetError() != gl.NO_ERROR {
panic("draw error")
}
}
func uploadTexture_RGBA32(w, h int, data []byte) gl.Texture {
id := gl.GenTexture()
id.Bind(gl.TEXTURE_2D)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_R, gl.CLAMP_TO_EDGE)
gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, int(w), int(h), 0, gl.RGBA, gl.UNSIGNED_BYTE, data)
if gl.GetError() != gl.NO_ERROR {
id.Delete()
panic("Failed to load a texture")
return 0
}
return id
}
//----------------------------------------------------------------------------
func GlErrorString() string {
code := gl.GetError()
if code == 0 {
return "NO GL ERROR"
}
index := uint32(code) - uint32(gl.INVALID_ENUM)
errorStrings := []string{
"GL_INVALID_ENUM",
"GL_INVALID_VALUE",
"GL_INVALID_OPERATION",
"GL_STACK_OVERFLOW",
"GL_STACK_UNDERFLOW",
"GL_OUT_OF_MEMORY",
"GL_UNKNOWN_ERROR_CODE"}
if 0 <= index && index < 6 {
return errorStrings[index]
}
return errorStrings[6]
}