Remove the remaining bits of deprecated GL usage

The drawing is now completely shader based, which makes away
with all usage of the depracted matrix stack. This also allows
us to do things like simple translations and texture coordinate
translation directly instead of doing everything indirectly
through matrices.

Fixed vertex attributes ('vertexPointer()' etc) are also
replaced with user defined attribute arrays.

shader/sprite.frag

@@ -5,19 +5,18 @@ uniform vec4 tone;
 
 uniform float opacity;
 uniform vec4 color;
-uniform vec4 flash;
 
 uniform float bushDepth;
-uniform float bushOpacity;
-
+uniform float bushOpacity;
+
+varying vec2 v_texCoord;
+
 const vec3 lumaF = { .299, .587, .114 };
 
 void main()
 {
-	vec2 coor = gl_TexCoord[0].xy;
-
 	/* Sample source color */
-	vec4 frag = texture2D(texture, coor);
+	vec4 frag = texture2D(texture, v_texCoord);
 	
 	/* Apply gray */
 	const float luma = dot(frag.rgb, lumaF);
@@ -32,11 +31,8 @@ void main()
 	/* Apply color */
 	frag.rgb = mix(frag.rgb, color.rgb, color.a);
 
-	/* Apply flash */
-	frag.rgb = mix(frag.rgb, flash.rgb, flash.a);
-
 	/* Apply bush alpha by mathematical if */
-	float underBush = float(coor.y < bushDepth);
+	float underBush = float(v_texCoord.y < bushDepth);
 	frag.a *= clamp(bushOpacity + underBush, 0, 1);
 	
 	gl_FragColor = frag;