Treat UV gen mode 3 as GE_TEXMAP_TEXTURE_COORDS.

Fixes Riviera, #2214.

GPU/GLES/TransformPipeline.cpp

@@ -670,13 +670,14 @@ void TransformDrawEngine::SoftwareTransformAndDraw(
 			// Perform texture coordinate generation after the transform and lighting - one style of UV depends on lights.
 			switch (gstate.getUVGenMode())
 			{
-			case 0:	// UV mapping
+			case GE_TEXMAP_TEXTURE_COORDS:	// UV mapping
+			case GE_TEXMAP_UNKNOWN: // Seen in Riviera.  Unsure of meaning, but this works.
 				// Texture scale/offset is only performed in this mode.
 				uv[0] = uscale * (ruv[0]*gstate_c.uv.uScale + gstate_c.uv.uOff);
 				uv[1] = vscale * (ruv[1]*gstate_c.uv.vScale + gstate_c.uv.vOff);
 				uv[2] = 1.0f;
 				break;
-			case 1:
+			case GE_TEXMAP_TEXTURE_MATRIX:
 				{
 					// Projection mapping
 					Vec3f source;
@@ -713,7 +714,7 @@ void TransformDrawEngine::SoftwareTransformAndDraw(
 					uv[2] = uvw[2];
 				}
 				break;
-			case 2:
+			case GE_TEXMAP_ENVIRONMENT_MAP:
 				// Shade mapping - use two light sources to generate U and V.
 				{
 					Vec3f lightpos0 = Vec3f(gstate_c.lightpos[gstate.getUVLS0()]).Normalized();
@@ -726,6 +727,7 @@ void TransformDrawEngine::SoftwareTransformAndDraw(
 				break;
 			default:
 				// Illegal
+				ERROR_LOG_REPORT(G3D, "Impossible UV gen mode? %d", gstate.getUVGenMode());
 				break;
 			}
 			uv[0] = uv[0] * widthFactor;

GPU/ge_constants.h

@@ -459,9 +459,10 @@ enum GEStencilOp
 
 enum GETexMapMode
 {
-	GE_TEXMAP_TEXTURE_COORDS=0,
-	GE_TEXMAP_TEXTURE_MATRIX=1,
-	GE_TEXMAP_ENVIRONMENT_MAP=2,
+	GE_TEXMAP_TEXTURE_COORDS = 0,
+	GE_TEXMAP_TEXTURE_MATRIX = 1,
+	GE_TEXMAP_ENVIRONMENT_MAP = 2,
+	GE_TEXMAP_UNKNOWN = 3,
 };
 
 enum GETexProjMapMode