From b78becde4c6a8994e3ccbce84f97ba4a3d650c6e Mon Sep 17 00:00:00 2001
From: Daniel Gibson <metalcaedes@gmail.com>
Date: Mon, 3 Mar 2025 05:49:16 +0100
Subject: [PATCH] Fix loading ridiculously large non-POT-textures

After loading a texture, Doom3 calculates an MD4-sum of it.. this is
mostly pointless and only used for the "reportImageDuplication" console
command, but whatever.
The problem here was that the image was 32000x2000 pixels (due to some
error when creating it) which dhewm3 wanted to convert to the next
bigger power-of-two values with R_ResampleTexture(), but that function
clamps to 4096x4096, so the actually used pixeldata was for 2048x4096.
However, R_ResampleTexture() didn't communicate this to its caller,
and thus a too big size was used for calculating the MD4-sum and it
crashed.

That's fixed now and also a warning is printed about this.
---
 neo/renderer/Image.h           |  2 +-
 neo/renderer/Image_files.cpp   | 12 +++++++++---
 neo/renderer/Image_process.cpp | 12 +++++++-----
 3 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/neo/renderer/Image.h b/neo/renderer/Image.h
index 34515a37..5eac4531 100644
--- a/neo/renderer/Image.h
+++ b/neo/renderer/Image.h
@@ -468,7 +468,7 @@ FIXME: make an "imageBlock" type to hold byte*,width,height?
 byte *R_Dropsample( const byte *in, int inwidth, int inheight,
 							int outwidth, int outheight );
 byte *R_ResampleTexture( const byte *in, int inwidth, int inheight,
-							int outwidth, int outheight );
+							int& outwidth, int& outheight );
 byte *R_MipMapWithAlphaSpecularity( const byte *in, int width, int height );
 byte *R_MipMap( const byte *in, int width, int height, bool preserveBorder );
 byte *R_MipMap3D( const byte *in, int width, int height, int depth, bool preserveBorder );
diff --git a/neo/renderer/Image_files.cpp b/neo/renderer/Image_files.cpp
index 174d544d..7871bc58 100644
--- a/neo/renderer/Image_files.cpp
+++ b/neo/renderer/Image_files.cpp
@@ -902,12 +902,18 @@ void R_LoadImage( const char *cname, byte **pic, int *width, int *height, ID_TIM
 			if ( globalImages->image_roundDown.GetBool() && scaled_height > h ) {
 				scaled_height >>= 1;
 			}
+			int outWidth = scaled_width;
+			int outHeight = scaled_height;
+			resampledBuffer = R_ResampleTexture( *pic, w, h, outWidth, outHeight );
+			if ( outWidth != scaled_width || outHeight != scaled_height ) {
+				common->Warning( "Texture '%s' didn't have power-of-two size *and* was too big, scaled from %dx%d to %dx%d",
+				                 name.c_str(), w, h, outWidth, outHeight );
+			}
 
-			resampledBuffer = R_ResampleTexture( *pic, w, h, scaled_width, scaled_height );
 			R_StaticFree( *pic );
 			*pic = resampledBuffer;
-			*width = scaled_width;
-			*height = scaled_height;
+			*width = outWidth;
+			*height = outHeight;
 		}
 	}
 }
diff --git a/neo/renderer/Image_process.cpp b/neo/renderer/Image_process.cpp
index 920aad18..6027d930 100644
--- a/neo/renderer/Image_process.cpp
+++ b/neo/renderer/Image_process.cpp
@@ -46,7 +46,7 @@ after resampling to the next lower power of two.
 */
 #define	MAX_DIMENSION	4096
 byte *R_ResampleTexture( const byte *in, int inwidth, int inheight,
-							int outwidth, int outheight ) {
+							int& _outwidth, int& _outheight ) {
 	int		i, j;
 	const byte	*inrow, *inrow2;
 	unsigned int	frac, fracstep;
@@ -54,12 +54,14 @@ byte *R_ResampleTexture( const byte *in, int inwidth, int inheight,
 	const byte		*pix1, *pix2, *pix3, *pix4;
 	byte		*out, *out_p;
 
-	if ( outwidth > MAX_DIMENSION ) {
-		outwidth = MAX_DIMENSION;
+	if ( _outwidth > MAX_DIMENSION ) {
+		_outwidth = MAX_DIMENSION;
 	}
-	if ( outheight > MAX_DIMENSION ) {
-		outheight = MAX_DIMENSION;
+	if ( _outheight > MAX_DIMENSION ) {
+		_outheight = MAX_DIMENSION;
 	}
+	int outwidth = _outwidth;
+	int outheight = _outheight;
 
 	out = (byte *)R_StaticAlloc( outwidth * outheight * 4 );
 	out_p = out;