gl2shim: add glsl100 support

ref/gl/gl2_shim/fragment.glsl.inc

@@ -6,9 +6,14 @@
 "#define in varying\n"
 "#define texture texture2D\n"
 "#endif\n"
-"#if VER >= 130\n"
+"#if VER >= 130 || VER == 100\n"
 "precision mediump float;\n"
 "#endif\n"
+"#if VER == 100\n"
+"#define PREC mediump\n"
+"#else\n"
+"#define PREC\n"
+"#endif\n"
 "#if ATTR_TEXCOORD0\n"
 "uniform sampler2D uTex0;\n"
 "#endif\n"
@@ -19,20 +24,20 @@
 "uniform float uAlphaTest;\n"
 "#endif\n"
 "#if FEAT_FOG\n"
-"uniform vec4 uFog;\n"
+"uniform PREC vec4 uFog;\n"
 "#endif\n"
-"uniform vec4 uColor;\n"
+"uniform PREC vec4 uColor;\n"
 "#if ATTR_COLOR\n"
-"in vec4 vColor;\n"
+"in PREC vec4 vColor;\n"
 "#endif\n"
 "#if ATTR_TEXCOORD0\n"
-"in vec2 vTexCoord0;\n"
+"in PREC vec2 vTexCoord0;\n"
 "#endif\n"
 "#if ATTR_TEXCOORD1\n"
-"in vec2 vTexCoord1;\n"
+"in PREC vec2 vTexCoord1;\n"
 "#endif\n"
 "#if ATTR_NORMAL\n"
-"in vec2 vNormal;\n"
+"in PREC vec2 vNormal;\n"
 "#endif\n"
 "#if VER >= 300\n"
 "out vec4 oFragColor;\n"
@@ -42,9 +47,9 @@
 "void main()\n"
 "{\n"
 "#if ATTR_COLOR\n"
-"vec4 c = vColor;\n"
+"PREC vec4 c = vColor;\n"
 "#else\n"
-"vec4 c = uColor;\n"
+"PREC vec4 c = uColor;\n"
 "#endif\n"
 "#if ATTR_TEXCOORD0\n"
 "c = c * texture(uTex0, vTexCoord0);\n"

ref/gl/gl2_shim/gl2_shim.c

@@ -583,7 +583,7 @@ int GL2_ShimInit( void )
 
 	gl2wrap_config.version = 310;
 	if( gEngfuncs.Sys_CheckParm("-minshaders") )
-		gl2wrap_config.version = 110;
+		gl2wrap_config.version = 100;
 	if(gl2wrap_config.buf_storage)
 		gl2wrap_config.incremental = true, gl2wrap_config.vao_mandatory = true;
 	if(!pglBindVertexArray || !gl2wrap_config.vao_mandatory)
@@ -658,7 +658,11 @@ int GL2_ShimInit( void )
 		{
 			gl2wrap_config.version = 110;
 			if(!GL2_InitProgs())
-				gEngfuncs.Host_Error("Failed to compile shaders!\n");
+			{
+				gl2wrap_config.version = 100;
+				if(!GL2_InitProgs())
+					gEngfuncs.Host_Error("Failed to compile shaders!\n");
+			}
 		}
 	}