renderer: introduce and use IF_NOALPHA

Author: illwieckz

src/engine/renderer/tr_bsp.cpp

@@ -483,8 +483,8 @@ static void R_LoadLightmaps( lump_t *l, const char *bspName )
 		return;
 	}
 
-	int lightMapBits = IF_LIGHTMAP | IF_NOPICMIP;
-	int deluxeMapBits = IF_NORMALMAP | IF_NOPICMIP;
+	int lightMapBits = IF_LIGHTMAP | IF_NOALPHA | IF_NOPICMIP;
+	int deluxeMapBits = IF_NORMALMAP | IF_NOALPHA | IF_NOPICMIP;
 
 	if ( tr.worldLinearizeLightMap )
 	{

src/engine/renderer/tr_image.cpp

@@ -1054,17 +1054,14 @@ void R_UploadImage( const char *name, const byte **dataArray, int numLayers, int
 	}
 	else
 	{
-		// lightmap does not have alpha channel
-		if ( image->bits & IF_LIGHTMAP )
-		{
-			internalFormat = GL_RGB8;
-		}
-		else
-		{
-			internalFormat = GL_RGBA8;
-		}
+		internalFormat = GL_RGBA8;
 	}
 
+	if ( internalFormat == GL_RGBA8 && image->bits & IF_NOALPHA )
+	{
+		internalFormat = GL_RGB8;
+	}
+
 	if ( internalFormat == GL_RGB8 )
 	{
 		c = image->width * image->height;
@@ -2776,13 +2773,13 @@ void R_CreateBuiltinImages()
 	memset( data, 255, sizeof( data ) );
 
 	imageParams_t imageParams = {};
-	imageParams.bits = IF_NOPICMIP;
+	imageParams.bits = IF_NOPICMIP | IF_NOALPHA;
 	imageParams.filterType = filterType_t::FT_LINEAR;
 	imageParams.wrapType = wrapTypeEnum_t::WT_REPEAT;
 
 	tr.whiteImage = R_CreateImage( "_white", ( const byte ** ) &dataPtr, DIMENSION, DIMENSION, 1, imageParams );
 
-	imageParams.bits = IF_NOPICMIP | IF_RED;
+	imageParams.bits = IF_NOPICMIP | IF_NOALPHA | IF_RED;
 
 	// we use a solid black image instead of disabling texturing
 	memset( data, 0, sizeof( data ) );
@@ -2804,7 +2801,7 @@ void R_CreateBuiltinImages()
 		out[ 1 ] = out[ 3 ] = 255;
 	}
 
-	imageParams.bits = IF_NOPICMIP;
+	imageParams.bits = IF_NOPICMIP | IF_NOALPHA;
 
 	tr.greenImage = R_CreateImage( "_green", ( const byte ** ) &dataPtr, DIMENSION, DIMENSION, 1, imageParams );
 
@@ -2825,11 +2822,11 @@ void R_CreateBuiltinImages()
 		out[ 3 ] = 255;
 	}
 
-	imageParams.bits = IF_NOPICMIP | IF_NORMALMAP;
+	imageParams.bits = IF_NOPICMIP | IF_NOALPHA | IF_NORMALMAP;
 
 	tr.flatImage = R_CreateImage( "_flat", ( const byte ** ) &dataPtr, DIMENSION, DIMENSION, 1, imageParams );
 
-	imageParams.bits = IF_NOPICMIP;
+	imageParams.bits = IF_NOPICMIP | IF_NOALPHA;
 	imageParams.wrapType = wrapTypeEnum_t::WT_CLAMP;
 
 	for ( image_t * &image : tr.cinematicImage )

src/engine/renderer/tr_local.h

@@ -484,7 +484,8 @@ enum class ssaoMode {
 	  IF_BC4 = BIT( 22 ),
 	  IF_BC5 = BIT( 23 ),
 	  IF_RGBA32UI = BIT( 24 ),
-	  IF_HOMEPATH = BIT( 25 )
+	  IF_HOMEPATH = BIT( 25 ),
+	  IF_NOALPHA = BIT( 26 )
 	};
 
 	enum class filterType_t