From b05a6bff8f929718baa0628d91bc3dc70aab8eb4 Mon Sep 17 00:00:00 2001
From: Epicalert <epicalert@protonmail.com>
Date: Wed, 13 Jan 2021 17:48:21 +0800
Subject: [PATCH] Use older GLSL ver for compatibility with OpenGL 2.1

---
 src/graphics.cpp | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/src/graphics.cpp b/src/graphics.cpp
index 2e18330..e3eb87d 100644
--- a/src/graphics.cpp
+++ b/src/graphics.cpp
@@ -112,10 +112,10 @@ void initTexture (GLuint* texNum, const char* path) {
 
 void initShader() {
 	const char* vsSrc = 
-		"#version 150\n"
-		"in vec2 position;"
-		"in vec2 texcoord;"
-		"out vec2 uv;"
+		"#version 120\n"
+		"attribute vec2 position;"
+		"attribute vec2 texcoord;"
+		"varying vec2 uv;"
 		"uniform mat4 transMatrix;"
 		"void main () {"
 		"gl_Position = transMatrix * vec4(position, 0.0, 1.0);"
@@ -123,12 +123,11 @@ void initShader() {
 		"}";
 
 	const char* fsSrc = 
-		"#version 150\n"
-		"in vec2 uv;"
-		"out vec4 color;"
+		"#version 120\n"
+		"varying vec2 uv;"
 		"uniform sampler2D tex;"
 		"void main () {"
-		"color = texture(tex, uv);"
+		"gl_FragColor = texture2D(tex, uv);"
 		"}";
 
 	//compile vert shader
@@ -152,7 +151,7 @@ void initShader() {
 	shader = glCreateProgram();
 	glAttachShader(shader, vs);
 	glAttachShader(shader, fs);
-	glBindFragDataLocation(shader, 0, "color");
+	//glBindFragDataLocation(shader, 0, "color");
 	glLinkProgram(shader);
 	glUseProgram(shader);