X-Git-Url: http://nitlanguage.org

diff --git a/lib/gamnit/flat.nit b/lib/gamnit/flat.nit
index 06ac8df..45d1ce9 100644
--- a/lib/gamnit/flat.nit
+++ b/lib/gamnit/flat.nit
@@ -52,7 +52,7 @@ class Sprite
 	# Position of this sprite in world coordinates
 	var center: Point3d[Float] is writable
 
-	# Rotation on the Z axis
+	# Rotation on the Z axis, where 0.0 points right and `0.5*pi` points up
 	var rotation = 0.0 is writable
 
 	# Mirror `texture` horizontally, inverting each pixel on the X axis
@@ -83,7 +83,7 @@ class Sprite
 		simple_2d_program.color.array_enabled = false
 		simple_2d_program.scale.array_enabled = false
 
-		simple_2d_program.translation.uniform(center.x, -center.y, center.z, 0.0)
+		simple_2d_program.translation.uniform(center.x, center.y, center.z, 0.0)
 		simple_2d_program.color.uniform(tint[0], tint[1], tint[2], tint[3])
 		simple_2d_program.scale.uniform scale
 
@@ -95,7 +95,7 @@ class Sprite
 			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)
+		simple_2d_program.rotation.uniform new Matrix.rotation(rotation, 0.0, 0.0, -1.0)
 
 		glDrawArrays(gl_TRIANGLE_STRIP, 0, 4)
 	end
@@ -128,7 +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
@@ -166,12 +166,11 @@ redef class App
 		# Prepare to draw
 		for tex in all_root_textures do
 			tex.load
+			gamnit_error = tex.error
+			if gamnit_error != null then print_error gamnit_error
 
 			glTexParameteri(gl_TEXTURE_2D, gl_TEXTURE_MIN_FILTER, gl_LINEAR)
 			glTexParameteri(gl_TEXTURE_2D, gl_TEXTURE_MAG_FILTER, gl_LINEAR)
-
-			gamnit_error = tex.error
-			assert gamnit_error == null else print_error gamnit_error
 		end
 	end