Restore legacy OpenGL 2.1 support.

glsl/combined.frag

@@ -3,8 +3,6 @@
 precision mediump float;
 #endif
 
-in vec4 vColor;
-
 uniform sampler2D Texture0;
 uniform sampler2D Texture1;
 uniform sampler2D Texture2;
@@ -18,6 +16,27 @@ uniform bool EnableDepthPreview;
 uniform float DepthTextureScale;
 uniform float AntialiasPixelsPerTexel;
 
+#if __VERSION__ == 120
+varying vec4 vTexCoord;
+varying vec2 vTexMetadata;
+varying vec4 vChannelMask;
+varying vec4 vDepthMask;
+varying vec2 vTexSampler;
+
+varying vec4 vColorFraction;
+varying vec4 vRGBAFraction;
+varying vec4 vPalettedFraction;
+
+uniform vec2 Texture0Size;
+uniform vec2 Texture1Size;
+uniform vec2 Texture2Size;
+uniform vec2 Texture3Size;
+uniform vec2 Texture4Size;
+uniform vec2 Texture5Size;
+uniform vec2 Texture6Size;
+#else
+in vec4 vColor;
+
 in vec4 vTexCoord;
 in vec2 vTexMetadata;
 in vec4 vChannelMask;
@@ -29,6 +48,7 @@ in vec4 vRGBAFraction;
 in vec4 vPalettedFraction;
 
 out vec4 fragColor;
+#endif
 
 float jet_r(float x)
 {
@@ -45,6 +65,43 @@ float jet_b(float x)
 	return x < 0.3 ? 4.0 * x + 0.5 : -4.0 * x + 2.5;
 }
 
+#if __VERSION__ == 120
+vec2 Size(float samplerIndex)
+{
+	if (samplerIndex < 0.5)
+		return Texture0Size;
+	else if (samplerIndex < 1.5)
+		return Texture1Size;
+	else if (samplerIndex < 2.5)
+		return Texture2Size;
+	else if (samplerIndex < 3.5)
+		return Texture3Size;
+	else if (samplerIndex < 4.5)
+		return Texture4Size;
+	else if (samplerIndex < 5.5)
+		return Texture5Size;
+
+	return Texture6Size;
+}
+
+vec4 Sample(float samplerIndex, vec2 pos)
+{
+	if (samplerIndex < 0.5)
+		return texture2D(Texture0, pos);
+	else if (samplerIndex < 1.5)
+		return texture2D(Texture1, pos);
+	else if (samplerIndex < 2.5)
+		return texture2D(Texture2, pos);
+	else if (samplerIndex < 3.5)
+		return texture2D(Texture3, pos);
+	else if (samplerIndex < 4.5)
+		return texture2D(Texture4, pos);
+	else if (samplerIndex < 5.5)
+		return texture2D(Texture5, pos);
+
+	return texture2D(Texture6, pos);
+}
+#else
 ivec2 Size(float samplerIndex)
 {
 	if (samplerIndex < 0.5)
@@ -80,6 +137,7 @@ vec4 Sample(float samplerIndex, vec2 pos)
 
 	return texture(Texture6, pos);
 }
+#endif
 
 vec4 SamplePalettedBilinear(float samplerIndex, vec2 coords, vec2 textureSize)
 {
@@ -93,10 +151,17 @@ vec4 SamplePalettedBilinear(float samplerIndex, vec2 coords, vec2 textureSize)
 	vec4 x3 = Sample(samplerIndex, tl + vec2(0., px.y));
 	vec4 x4 = Sample(samplerIndex, tl + px);
 
+	#if __VERSION__ == 120
+	vec4 c1 = texture2D(Palette, vec2(dot(x1, vChannelMask), vTexMetadata.s));
+	vec4 c2 = texture2D(Palette, vec2(dot(x2, vChannelMask), vTexMetadata.s));
+	vec4 c3 = texture2D(Palette, vec2(dot(x3, vChannelMask), vTexMetadata.s));
+	vec4 c4 = texture2D(Palette, vec2(dot(x4, vChannelMask), vTexMetadata.s));
+	#else
 	vec4 c1 = texture(Palette, vec2(dot(x1, vChannelMask), vTexMetadata.s));
 	vec4 c2 = texture(Palette, vec2(dot(x2, vChannelMask), vTexMetadata.s));
 	vec4 c3 = texture(Palette, vec2(dot(x3, vChannelMask), vTexMetadata.s));
 	vec4 c4 = texture(Palette, vec2(dot(x4, vChannelMask), vTexMetadata.s));
+	#endif
 
 	return mix(mix(c1, c2, interp.x), mix(c3, c4, interp.x), interp.y);
 }
@@ -127,7 +192,11 @@ void main()
 	{
 		vec4 x = Sample(vTexSampler.s, coords);
 		vec2 p = vec2(dot(x, vChannelMask), vTexMetadata.s);
+		#if __VERSION__ == 120
+		c = vPalettedFraction * texture2D(Palette, p) + vRGBAFraction * x + vColorFraction * vTexCoord;
+		#else
 		c = vPalettedFraction * texture(Palette, p) + vRGBAFraction * x + vColorFraction * vTexCoord;
+		#endif
 	}
 
 	// Discard any transparent fragments (both color and depth)
@@ -150,8 +219,16 @@ void main()
 		float r = clamp(jet_r(x), 0.0, 1.0);
 		float g = clamp(jet_g(x), 0.0, 1.0);
 		float b = clamp(jet_b(x), 0.0, 1.0);
+		#if __VERSION__ == 120
+		gl_FragColor = vec4(r, g, b, 1.0);
+		#else
 		fragColor = vec4(r, g, b, 1.0);
+		#endif
 	}
 	else
+	#if __VERSION__ == 120
+		gl_FragColor = c;
+		#else
 		fragColor = c;
+		#endif
 }

glsl/combined.vert

@@ -3,6 +3,21 @@
 uniform vec3 Scroll;
 uniform vec3 r1, r2;
 
+#if __VERSION__ == 120
+attribute vec4 aVertexPosition;
+attribute vec4 aVertexTexCoord;
+attribute vec2 aVertexTexMetadata;
+
+varying vec4 vTexCoord;
+varying vec2 vTexMetadata;
+varying vec4 vChannelMask;
+varying vec4 vDepthMask;
+varying vec2 vTexSampler;
+
+varying vec4 vColorFraction;
+varying vec4 vRGBAFraction;
+varying vec4 vPalettedFraction;
+#else
 in vec4 aVertexPosition;
 in vec4 aVertexTexCoord;
 in vec2 aVertexTexMetadata;
@@ -16,6 +31,7 @@ out vec2 vTexSampler;
 out vec4 vColorFraction;
 out vec4 vRGBAFraction;
 out vec4 vPalettedFraction;
+#endif
 
 vec4 UnpackChannelAttributes(float x)
 {

glsl/model.frag

@@ -9,13 +9,30 @@ uniform vec2 PaletteRows;
 uniform vec4 LightDirection;
 uniform vec3 AmbientLight, DiffuseLight;
 
+#if __VERSION__ == 120
+varying vec4 vTexCoord;
+varying vec4 vChannelMask;
+varying vec4 vNormalsMask;
+#else
 in vec4 vTexCoord;
 in vec4 vChannelMask;
 in vec4 vNormalsMask;
 out vec4 fragColor;
+#endif
 
 void main()
 {
+	#if __VERSION__ == 120
+	vec4 x = texture2D(DiffuseTexture, vTexCoord.st);
+	vec4 color = texture2D(Palette, vec2(dot(x, vChannelMask), PaletteRows.x));
+	if (color.a < 0.01)
+		discard;
+
+	vec4 y = texture2D(DiffuseTexture, vTexCoord.pq);
+	vec4 normal = (2.0 * texture2D(Palette, vec2(dot(y, vNormalsMask), PaletteRows.y)) - 1.0);
+	vec3 intensity = AmbientLight + DiffuseLight * max(dot(normal, LightDirection), 0.0);
+	gl_FragColor = vec4(intensity * color.rgb, color.a);
+	#else
 	vec4 x = texture(DiffuseTexture, vTexCoord.st);
 	vec4 color = texture(Palette, vec2(dot(x, vChannelMask), PaletteRows.x));
 	if (color.a < 0.01)
@@ -25,4 +42,5 @@ void main()
 	vec4 normal = (2.0 * texture(Palette, vec2(dot(y, vNormalsMask), PaletteRows.y)) - 1.0);
 	vec3 intensity = AmbientLight + DiffuseLight * max(dot(normal, LightDirection), 0.0);
 	fragColor = vec4(intensity * color.rgb, color.a);
+	#endif
 }

glsl/model.vert

@@ -3,12 +3,21 @@
 uniform mat4 View;
 uniform mat4 TransformMatrix;
 
+#if __VERSION__ == 120
+attribute vec4 aVertexPosition;
+attribute vec4 aVertexTexCoord;
+attribute vec2 aVertexTexMetadata;
+varying vec4 vTexCoord;
+varying vec4 vChannelMask;
+varying vec4 vNormalsMask;
+#else
 in vec4 aVertexPosition;
 in vec4 aVertexTexCoord;
 in vec2 aVertexTexMetadata;
 out vec4 vTexCoord;
 out vec4 vChannelMask;
 out vec4 vNormalsMask;
+#endif
 
 vec4 DecodeMask(float x)
 {