From a8019a1a1a420b73783fc76e6f5a8d8afeb59927 Mon Sep 17 00:00:00 2001
From: Patrick Walton <pcwalton@mimiga.net>
Date: Sat, 15 Feb 2020 18:00:25 -0800
Subject: [PATCH] Fix mask positioning on OpenGL

---
 resources/shaders/gl3/mask_winding.vs.glsl    | 7 ++++++-
 resources/shaders/metal/mask_winding.vs.metal | 4 +++-
 shaders/mask_winding.vs.glsl                  | 7 ++++++-
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/resources/shaders/gl3/mask_winding.vs.glsl b/resources/shaders/gl3/mask_winding.vs.glsl
index 2bd98862..a254c9b5 100644
--- a/resources/shaders/gl3/mask_winding.vs.glsl
+++ b/resources/shaders/gl3/mask_winding.vs.glsl
@@ -22,8 +22,13 @@ out vec2 vMaskTexCoord;
 out float vBackdrop;
 
 void main(){
+    vec2 position = mix(vec2(- 1.0), vec2(1.0), aPosition);
+
+
+
+
     vMaskTexCoord = aMaskTexCoord;
     vBackdrop = float(aBackdrop);
-    gl_Position = vec4(mix(vec2(- 1.0, 1.0), vec2(1.0, - 1.0), aPosition), 0.0, 1.0);
+    gl_Position = vec4(position, 0.0, 1.0);
 }
 
diff --git a/resources/shaders/metal/mask_winding.vs.metal b/resources/shaders/metal/mask_winding.vs.metal
index 6cce4f2f..acb17a02 100644
--- a/resources/shaders/metal/mask_winding.vs.metal
+++ b/resources/shaders/metal/mask_winding.vs.metal
@@ -21,9 +21,11 @@ struct main0_in
 vertex main0_out main0(main0_in in [[stage_in]])
 {
     main0_out out = {};
+    float2 position = mix(float2(-1.0), float2(1.0), in.aPosition);
+    position.y = -position.y;
     out.vMaskTexCoord = in.aMaskTexCoord;
     out.vBackdrop = float(in.aBackdrop);
-    out.gl_Position = float4(mix(float2(-1.0, 1.0), float2(1.0, -1.0), in.aPosition), 0.0, 1.0);
+    out.gl_Position = float4(position, 0.0, 1.0);
     return out;
 }
 
diff --git a/shaders/mask_winding.vs.glsl b/shaders/mask_winding.vs.glsl
index c757cb1f..c1e3cd81 100644
--- a/shaders/mask_winding.vs.glsl
+++ b/shaders/mask_winding.vs.glsl
@@ -20,7 +20,12 @@ out vec2 vMaskTexCoord;
 out float vBackdrop;
 
 void main() {
+    vec2 position = mix(vec2(-1.0), vec2(1.0), aPosition);
+#ifdef PF_ORIGIN_UPPER_LEFT
+    position.y = -position.y;
+#endif
+
     vMaskTexCoord = aMaskTexCoord;
     vBackdrop = float(aBackdrop);
-    gl_Position = vec4(mix(vec2(-1.0, 1.0), vec2(1.0, -1.0), aPosition), 0.0, 1.0);
+    gl_Position = vec4(position, 0.0, 1.0);
 }