Clean up RE_GenerateTexture

Fixes #271.

Author: slipher

src/engine/client/cl_cgame.cpp

@@ -1358,6 +1358,12 @@ void CGameVM::QVMSyscall(int syscallNum, Util::Reader& reader, IPC::Channel& cha
 
 		case CG_R_GENERATETEXTURE:
 			IPC::HandleMsg<Render::GenerateTextureMsg>(channel, std::move(reader), [this] (std::vector<byte> data, int x, int y, qhandle_t& handle) {
+				// Limit max size to avoid int overflow issues
+				if (x <= 0 || y <= 0 || x > 16384 || y > 16384 || size_t(x * y * 4) != data.size()) {
+					Log::Warn("GenerateTextureMsg: bad dimensions or size: %dx%d / %d bytes", x, y, data.size());
+					handle = 0;
+					return;
+				}
 				handle = re.GenerateTexture(data.data(), x, y);
 			});
 			break;

src/engine/renderer/tr_image.cpp

@@ -3184,26 +3184,18 @@ void RE_GetTextureSize( int textureID, int *width, int *height )
 	}
 }
 
-// This code is used to upload images produced by the game (like GUI elements produced by libRocket in Unvanquished)
-int numTextures = 0;
-
+// This code is used to upload images produced by the game (like glyphs produced by RMLUI in Unvanquished)
 qhandle_t RE_GenerateTexture( const byte *pic, int width, int height )
 {
-	size_t size = width * height;
-
-	if ( !size ) {
-		Log::Warn("RE_GenerateTexture: image size %dx%d is 0", width, height );
-		return 0;
-	}
-
 	R_SyncRenderThread();
 
-	const char *name = va( "rocket%d", numTextures++ );
+	std::string name = Str::Format( "$generatedTexture%d", tr.numGeneratedTextures++ );
 
 	imageParams_t imageParams = {};
 	imageParams.bits = IF_NOPICMIP;
 	imageParams.filterType = filterType_t::FT_LINEAR;
 	imageParams.wrapType = wrapTypeEnum_t::WT_CLAMP;
 
-	return RE_RegisterShaderFromImage( name, R_CreateImage( name, &pic, width, height, 1, imageParams ) );
+	return RE_RegisterShaderFromImage(
+		name.c_str(), R_CreateImage( name.c_str(), &pic, width, height, 1, imageParams ) );
 }

src/engine/renderer/tr_local.h

@@ -2849,6 +2849,8 @@ enum class ssaoMode {
 
 		std::vector<image_t *> images;
 
+		unsigned numGeneratedTextures;
+
 		int             numFBOs;
 		FBO_t           *fbos[ MAX_FBOS ];