1 files changed, 10 insertions, 3 deletions
diff --git a/src/video_core/host_shaders/full_screen_triangle.vert b/src/video_core/host_shaders/full_screen_triangle.vert
index 2c976b19f..d16d98995 100644
--- a/src/video_core/host_shaders/full_screen_triangle.vert
+++ b/src/video_core/host_shaders/full_screen_triangle.vert
@@ -4,13 +4,20 @@
 #version 450
 
 #ifdef VULKAN
+#define VERTEX_ID gl_VertexIndex
 #define BEGIN_PUSH_CONSTANTS layout(push_constant) uniform PushConstants {
 #define END_PUSH_CONSTANTS };
 #define UNIFORM(n)
+#define FLIPY 1
 #else // ^^^ Vulkan ^^^ // vvv OpenGL vvv
+#define VERTEX_ID gl_VertexID
 #define BEGIN_PUSH_CONSTANTS
 #define END_PUSH_CONSTANTS
+#define FLIPY -1
 #define UNIFORM(n) layout (location = n) uniform
+out gl_PerVertex {
+    vec4 gl_Position;
+};
 #endif
 
 BEGIN_PUSH_CONSTANTS
@@ -21,8 +28,8 @@ END_PUSH_CONSTANTS
 layout(location = 0) out vec2 texcoord;
 
 void main() {
-    float x = float((gl_VertexIndex & 1) << 2);
-    float y = float((gl_VertexIndex & 2) << 1);
-    gl_Position = vec4(x - 1.0, y - 1.0, 0.0, 1.0);
+    float x = float((VERTEX_ID & 1) << 2);
+    float y = float((VERTEX_ID & 2) << 1);
+    gl_Position = vec4(x - 1.0, FLIPY * (y - 1.0), 0.0, 1.0);
     texcoord = fma(vec2(x, y) / 2.0, tex_scale, tex_offset);
 }