Add working gl_image_t

Author: chutsu

src/gui.h

@@ -0,0 +1,7 @@
+#version 330 core
+in vec3 color;
+out vec4 frag_color;
+
+void main() {
+  frag_color = vec4(color, 1.0f);
+}

src/shaders/button.frag

@@ -0,0 +1,6 @@
+#version 330 core
+layout (location = 0) in vec2 aPos;
+
+void main() {
+  gl_Position = vec4(aPos, 0.0, 1.0);
+}

src/shaders/button.vert

@@ -0,0 +1,9 @@
+#version 330 core
+in vec2 TexCoord;
+out vec4 FragColor;
+uniform sampler2D texture1;
+
+void main()
+{
+	FragColor = texture(texture1, TexCoord);
+}

src/shaders/image.frag

@@ -0,0 +1,9 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;
+layout (location = 1) in vec2 aTexCoord;
+out vec2 TexCoord;
+
+void main() {
+  gl_Position = vec4(aPos, 1.0);
+  TexCoord = aTexCoord;
+}

src/shaders/image.vert

@@ -1,6 +1,6 @@
 #version 330 core
-out vec4 FragColor;
 in vec2 TexCoords;
+out vec4 FragColor;
 
 uniform sampler2D texture_diffuse1;