lib/gamnit: fix clock starting at first usage, not with the program

[nit.git] / lib / gamnit / flat.nit

diff --git a/lib/gamnit/flat.nit b/lib/gamnit/flat.nit
index ab433bf..1936763 100644 (file)
--- a/lib/gamnit/flat.nit
+++ b/lib/gamnit/flat.nit
@@ -55,11 +55,22 @@ class Sprite
        # Rotation on the Z axis
        var rotation = 0.0 is writable
 
+       # Mirror `texture` horizontally, inverting each pixel on the X axis
+       var invert_x = false is writable
+
        # Scale applied to this sprite
        var scale = 1.0 is writable
 
        # Transparency applied to the texture on draw
-       var alpha = 1.0 is writable
+       fun alpha: Float do return tint[3]
+
+       # Transparency applied to the texture on draw
+       fun alpha=(value: Float) do tint[3] = value
+
+       # Tint applied to the texture on draw
+       #
+       # Require: `tint.length == 4`
+       var tint: Array[Float] = [1.0, 1.0, 1.0, 1.0] is writable
 
        private fun draw
        do
@@ -73,12 +84,15 @@ class Sprite
                simple_2d_program.scale.array_enabled = false
 
                simple_2d_program.translation.uniform(center.x, -center.y, center.z, 0.0)
-               simple_2d_program.color.uniform(1.0, 1.0, 1.0, alpha)
+               simple_2d_program.color.uniform(tint[0], tint[1], tint[2], tint[3])
                simple_2d_program.scale.uniform scale
 
                simple_2d_program.use_texture.uniform true
                simple_2d_program.texture.uniform 0
-               simple_2d_program.tex_coord.array(texture.texture_coords, 2)
+               simple_2d_program.tex_coord.array(
+                       if invert_x then
+                               texture.texture_coords_invert_x
+                       else texture.texture_coords, 2)
                simple_2d_program.coord.array(texture.vertices, 3)
 
                simple_2d_program.rotation.uniform new Matrix.rotation(rotation, 0.0, 0.0, 1.0)
@@ -114,7 +128,7 @@ redef class App
        # UI sprites to draw in reference to `ui_camera`, over world `sprites`
        var ui_sprites: Sequence[Sprite] = new List[Sprite]
 
-       private var clock = new Clock
+       private var clock = new Clock is lazy
 
        redef fun on_create
        do
@@ -287,6 +301,18 @@ redef class Texture
                for v in [c, d, a, b] do texture_coords.add_all v
                return texture_coords
        end
+
+       # Coordinates of this texture on the `root` texture, with the X axis inverted
+       private var texture_coords_invert_x: Array[Float] is lazy do
+               var a = [offset_left,  offset_bottom]
+               var b = [offset_right, offset_bottom]
+               var c = [offset_left,  offset_top]
+               var d = [offset_right, offset_top]
+
+               var texture_coords = new Array[Float]
+               for v in [d, c, b, a] do texture_coords.add_all v
+               return texture_coords
+       end
 end
 
 # Graphic program to display simple models with a texture, translation, rotation and scale