From d86ff9011a4b304121ee75ed5f6352b426f9852a Mon Sep 17 00:00:00 2001
From: Patrick Walton <pcwalton@mimiga.net>
Date: Fri, 21 Jun 2019 18:04:18 -0700
Subject: [PATCH] Update the postprocessing shader and vertex array for the
 Metal changes.

Closes #201.
---
 renderer/src/gpu/renderer.rs          |  4 ++--
 resources/shaders/gl3/post.vs.glsl    | 10 ++++++++--
 resources/shaders/metal/post.vs.metal |  6 ++++--
 shaders/post.vs.glsl                  | 10 ++++++++--
 4 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/renderer/src/gpu/renderer.rs b/renderer/src/gpu/renderer.rs
index 87565d36..f70f56d7 100644
--- a/renderer/src/gpu/renderer.rs
+++ b/renderer/src/gpu/renderer.rs
@@ -654,7 +654,7 @@ where
             }
         }
 
-        self.device.draw_arrays(4, &RenderState {
+        self.device.draw_elements(6, &RenderState {
             target: &self.dest_render_target(),
             program: &self.postprocess_program.program,
             vertex_array: &self.postprocess_vertex_array.vertex_array,
@@ -1451,7 +1451,7 @@ where
         device.configure_vertex_attr(&vertex_array, &position_attr, &VertexAttrDescriptor {
             size: 2,
             class: VertexAttrClass::Int,
-            attr_type: VertexAttrType::U16,
+            attr_type: VertexAttrType::I16,
             stride: 4,
             offset: 0,
             divisor: 0,
diff --git a/resources/shaders/gl3/post.vs.glsl b/resources/shaders/gl3/post.vs.glsl
index b30dcf8d..a1d8effb 100644
--- a/resources/shaders/gl3/post.vs.glsl
+++ b/resources/shaders/gl3/post.vs.glsl
@@ -19,7 +19,13 @@ in ivec2 aPosition;
 out vec2 vTexCoord;
 
 void main(){
-    vTexCoord = vec2(aPosition);
-    gl_Position = vec4(vec2(aPosition)* 2.0 - 1.0, 0.0, 1.0);
+    vec2 position = vec2(aPosition);
+    vTexCoord = position;
+
+
+
+
+
+    gl_Position = vec4(vec2(position)* 2.0 - 1.0, 0.0, 1.0);
 }
 
diff --git a/resources/shaders/metal/post.vs.metal b/resources/shaders/metal/post.vs.metal
index 0fcc0bf6..f7385038 100644
--- a/resources/shaders/metal/post.vs.metal
+++ b/resources/shaders/metal/post.vs.metal
@@ -18,8 +18,10 @@ struct main0_in
 vertex main0_out main0(main0_in in [[stage_in]])
 {
     main0_out out = {};
-    out.vTexCoord = float2(in.aPosition);
-    out.gl_Position = float4((float2(in.aPosition) * 2.0) - float2(1.0), 0.0, 1.0);
+    float2 position = float2(in.aPosition);
+    out.vTexCoord = position;
+    position.y = 1.0 - position.y;
+    out.gl_Position = float4((float2(position) * 2.0) - float2(1.0), 0.0, 1.0);
     return out;
 }
 
diff --git a/shaders/post.vs.glsl b/shaders/post.vs.glsl
index 137cf388..52cf3eea 100644
--- a/shaders/post.vs.glsl
+++ b/shaders/post.vs.glsl
@@ -17,6 +17,12 @@ in ivec2 aPosition;
 out vec2 vTexCoord;
 
 void main() {
-    vTexCoord = vec2(aPosition);
-    gl_Position = vec4(vec2(aPosition) * 2.0 - 1.0, 0.0, 1.0);
+    vec2 position = vec2(aPosition);
+    vTexCoord = position;
+
+#ifdef PF_ORIGIN_UPPER_LEFT
+    // FIXME(pcwalton): This is wrong.
+    position.y = 1.0 - position.y;
+#endif
+    gl_Position = vec4(vec2(position) * 2.0 - 1.0, 0.0, 1.0);
 }