# See the License for the specific language governing permissions and
# limitations under the License.
-# Services to load textures, create subtextures and manage their life-cycle
+# Load textures, create subtextures and manage their life-cycle
module textures
import display
-# Abstract gamnit texture
+# Texture composed of pixels, loaded from the assets folder by default
+#
+# Most textures should be created with `App` (as attributes)
+# for the method `on_create` to load them.
+#
+# ~~~
+# import gamnit::flat
+#
+# redef class App
+# # Create the texture object, it will be loaded automatically
+# var texture = new Texture("path/in/assets.png")
+#
+# redef fun on_create()
+# do
+# # Let `on_create` load the texture
+# super
+#
+# # Use the texture
+# var sprite = new Sprite(texture, new Point3d[Float](0.0, 0.0, 0.0))
+# app.sprites.add sprite
+# end
+# end
+# ~~~
+#
+# Otherwise, they can be loaded and error checked explicitly after `on_create`.
+#
+# ~~~nitish
+# var texture = new Texture("path/in/assets.png")
+# texture.load
+# var error = texture.error
+# if error != null then print_error error
+# ~~~
+#
+# A texture may also be created programmatically, like `CheckerTexture`,
+# or derived from another texture, using `subtexture`.
+# Textures with actual pixel data (not `Subtexture`) are `RootTexture`.
+# Texture loaded from the assets folder may in the PNG or JPG formats.
abstract class Texture
# Prepare a texture located at `path` within the `assets` folder
- new (path: Text) do return new GamnitAssetTexture(path.to_s)
+ new (path: Text) do return new TextureAsset(path.to_s)
- # Root texture of which `self` is derived
- fun root: GamnitRootTexture is abstract
+ # Root texture from which `self` is derived
+ fun root: RootTexture is abstract
# Width in pixels of this texture
var width = 0.0
# OpenGL handle to this texture
fun gl_texture: Int do return root.gl_texture
- # Prepare a subtexture from this texture
- fun subtexture(left, top, width, height: Numeric): GamnitSubtexture
+ # Prepare a subtexture from this texture, from the given pixel offsets
+ fun subtexture(left, top, width, height: Numeric): Subtexture
do
# Setup the subtexture
- var subtex = new GamnitSubtexture(root, self, left.to_f, top.to_f, width.to_f, height.to_f)
+ var subtex = new Subtexture(root, self, left.to_f, top.to_f, width.to_f, height.to_f)
return subtex
end
# Colorful small texture of 2x2 pixels
class CheckerTexture
- super GamnitRootTexture
+ super RootTexture
redef fun load(force)
do
end
# Texture with its own pixels
-class GamnitRootTexture
+class RootTexture
super Texture
redef fun root do return self
private fun load_from_pixels(pixels: Pointer, width, height: Int, format: GLPixelFormat)
do
- var max_texture_size = glGetIntegerv(gl_MAX_TEXTURE_SIZE)
+ var max_texture_size = glGetIntegerv(gl_MAX_TEXTURE_SIZE, 0)
if width > max_texture_size or height > max_texture_size then
error = new Error("Texture {self} width or height is over the GL_MAX_TEXTURE_SIZE of {max_texture_size}")
return
glBindTexture(gl_TEXTURE_2D, gl_texture)
var param = if pixelated then gl_NEAREST else gl_LINEAR
- glTexParameteri(gl_TEXTURE_2D, gl_TEXTURE_MIN_FILTER, param)
glTexParameteri(gl_TEXTURE_2D, gl_TEXTURE_MAG_FILTER, param)
end
end
# Texture loaded from the assets folder
-class GamnitAssetTexture
- super GamnitRootTexture
+class TextureAsset
+ super RootTexture
# Path to this texture within the `assets` folder
var path: String
end
# Texture derived from another texture, does not own its pixels
-class GamnitSubtexture
+class Subtexture
super Texture
redef var root