func loadTextures() (err error) {
gl.GenTextures(textures)
// Texture 1
textures[0].Bind(gl.TEXTURE_2D)
if !glfw.LoadTexture2D(texturefile, 0) {
return errors.New("Failed to load texture: " + texturefile)
}
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
// Texture 2
textures[1].Bind(gl.TEXTURE_2D)
if !glfw.LoadTexture2D(texturefile, 0) {
return errors.New("Failed to load texture: " + texturefile)
}
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
// Texture 3
textures[2].Bind(gl.TEXTURE_2D)
if !glfw.LoadTexture2D(texturefile, glfw.BuildMipmapsBit) {
return errors.New("Failed to load texture: " + texturefile)
}
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR_MIPMAP_NEAREST)
return
}
func loadTextures() (err error) {
textures = make([]gl.Texture, len(texturefiles))
gl.GenTextures(textures)
for i := range texturefiles {
textures[i].Bind(gl.TEXTURE_2D)
if glfw.LoadTexture2D(texturefiles[i], 0) {
return errors.New("Failed to load texture: " + texturefiles[i])
}
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
}
return
}
// load in bitmap as a GL texture
func LoadGLTextures(path string) {
// storage space for the textures
image, format := LoadImage(path)
// Create the textures
gl.GenTextures(textures[:])
genTexture(textures[0], image, format)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
genTexture(textures[1], image, format)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
genTexture(textures[2], image, format)
gl.TexParameteri(gl.TEXTURE_2D, gl.GENERATE_MIPMAP, gl.TRUE)
}
// load in bitmap as a GL texture
func LoadGLTextures(path string) {
image := sdl.Load(path)
if image == nil {
panic(sdl.GetError())
}
// Check that the image's width is a power of 2
if image.W&(image.W-1) != 0 {
fmt.Println("warning:", path, "has a width that is not a power of 2")
}
// Also check if the height is a power of 2
if image.H&(image.H-1) != 0 {
fmt.Println("warning:", path, "has an height that is not a power of 2")
}
// get the number of channels in the SDL surface
nOfColors := image.Format.BytesPerPixel
var textureFormat gl.GLenum
if nOfColors == 4 { // contains alpha channel
if image.Format.Rmask == 0x000000ff {
textureFormat = gl.RGBA
} else {
textureFormat = gl.BGRA
}
} else if nOfColors == 3 { // no alpha channel
if image.Format.Rmask == 0x000000ff {
textureFormat = gl.RGB
} else {
textureFormat = gl.BGR
}
} else {
fmt.Println("warning:", path, "is not truecolor, this will probably break")
}
// Create the textures
gl.GenTextures(textures[:])
// First texture
gl.BindTexture(gl.TEXTURE_2D, uint(textures[0]))
gl.TexImage2D(
gl.TEXTURE_2D,
0,
3,
int(image.W),
int(image.H),
0,
textureFormat,
gl.UNSIGNED_BYTE,
image.Pixels,
)
// linear filtering
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
// Second texture
gl.BindTexture(gl.TEXTURE_2D, uint(textures[1]))
gl.TexImage2D(gl.TEXTURE_2D, 0,
3,
int(image.W),
int(image.H),
0, textureFormat, gl.UNSIGNED_BYTE,
image.Pixels,
)
// Mipmapped filtering
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
// Third texture
gl.BindTexture(gl.TEXTURE_2D, uint(textures[2]))
gl.TexImage2D(gl.TEXTURE_2D, 0,
3,
int(image.W),
int(image.H),
0, textureFormat, gl.UNSIGNED_BYTE,
image.Pixels,
)
// Mipmapped filtering
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR_MIPMAP_NEAREST)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
glu.Build2DMipmaps(
gl.TEXTURE_2D,
3,
int(image.W),
int(image.H),
textureFormat,
image.Pixels,
)
}