+ # Width and height in pixels, defaults to 32
+ var size = 32 is optional
+
+ redef fun load(force)
+ do
+ if gl_texture != -1 then return
+ load_checker size
+ loaded = true
+ end
+end
+
+# Custom texture with pixel values filled programmatically
+#
+# At creation, the texture is composed of `width` by `height` (rounded down)
+# transparent pixels. The pixels value can be set using `[]=`.
+#
+# ~~~
+# # Build a texture with 4 colors
+# var tex = new CustomTexture(2.0, 2.0)
+# tex[0, 0] = [1.0, 0.0, 0.0] # Red
+# tex[0, 1] = [0.0, 1.0, 0.0] # Green
+# tex[1, 0] = [0.0, 0.0, 1.0] # Blue
+# tex[1, 1] = [1.0, 1.0, 1.0, 0.5] # Transparent white
+# tex.load
+# ~~~
+class CustomTexture
+ super RootTexture
+
+ redef var width
+ redef var height
+
+ private var cpixels = new CByteArray(4*width.to_i*height.to_i) is lazy
+
+ # Set the `color` of the pixel at `x`, `y` (from the top-left corner)
+ #
+ # The argument `color` should be an array of up to 4 floats (RGBA).
+ # If `color` has less than 4 items, the missing items are replaced by 1.0.
+ #
+ # Require: `not loaded and x < width.to_i and y < height.to_i`
+ fun []=(x, y: Int, color: Array[Float])
+ do
+ assert not loaded else print_error "{class_name}::[]= already loaded"
+ assert x < width.to_i and y < height.to_i else print_error "{class_name}::[] out of bounds"
+
+ # Simple conversion from [0.0..1.0] to [0..255]
+ var bytes = [for c in color do (c*255.0).round.to_i.clamp(0, 255).to_bytes.last]
+ while bytes.length < 4 do bytes.add 255u8
+
+ var offset = 4*(x + y*width.to_i)
+ for i in [0..4[ do cpixels[offset+i] = bytes[i]
+ end
+
+ # Overwrite all pixels with `color`
+ #
+ # The argument `color` should be an array of up to 4 floats (RGBA).
+ # If `color` has less than 4 items, the missing items are replaced by 1.0.
+ #
+ # Require: `not loaded`
+ fun fill(color: Array[Float])
+ do
+ assert not loaded else print_error "{class_name}::fill already loaded"
+
+ # Simple conversion from [0.0..1.0] to [0..255]
+ var bytes = [for c in color do (c*255.0).round.to_i.clamp(0, 255).to_bytes.last]
+ while bytes.length < 4 do bytes.add 255u8
+
+ var i = 0
+ for x in [0..width.to_i[ do
+ for y in [0..height.to_i[ do
+ for j in [0..4[ do cpixels[i+j] = bytes[j]
+ i += 4
+ end
+ end
+ end
+