From 71c65522581c48cb63ce0355d1fcc68abf32f9a2 Mon Sep 17 00:00:00 2001
From: Magnus Norddahl <dpjudas@users.noreply.github.com>
Date: Thu, 30 Jun 2022 23:59:37 +0200
Subject: [PATCH] Prepare the vertex shader to draw without a vertex buffer

---
 src/lightmap/glsl_vert.h | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/lightmap/glsl_vert.h b/src/lightmap/glsl_vert.h
index 1d61ded..d526320 100644
--- a/src/lightmap/glsl_vert.h
+++ b/src/lightmap/glsl_vert.h
@@ -20,10 +20,17 @@ layout(push_constant) uniform PushConstants
 
 layout(location = 0) out vec3 worldpos;
 
+vec2 positions[4] = vec2[](
+	vec2(0.0, 0.0),
+	vec2(0.0, 1.0),
+	vec2(1.0, 1.0),
+	vec2(1.0, 0.0)
+);
+
 void main()
 {
 	worldpos = vec3(0.0);
-	gl_Position = vec4(0.0, 0.0, 0.0, 1.0);
+	gl_Position = vec4(positions[gl_VertexIndex] * 2.0 - 1.0, 0.0, 1.0);
 }
 
 )glsl";