From 218fdaeaf898d1e35072256a9be7d48ae809f177 Mon Sep 17 00:00:00 2001
From: Jaime Passos <lazymyuutsu@gmail.com>
Date: Mon, 6 Jan 2020 20:39:38 -0300
Subject: [PATCH] Fix patch conversion

---
 src/r_picformats.c | 23 ++++++++++++++++-------
 src/r_plane.c      |  2 +-
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/src/r_picformats.c b/src/r_picformats.c
index a8ae01f13..ebeb35b7b 100644
--- a/src/r_picformats.c
+++ b/src/r_picformats.c
@@ -926,9 +926,15 @@ void *Picture_PNGConvert(
 	png_bytep *row_pointers = PNG_Read(png, w, h, topoffset, leftoffset, insize);
 	png_uint_32 width = *w, height = *h;
 
-	outbpp = Picture_FormatBPP(outformat);
-	if (!outbpp)
-		I_Error("Picture_PNGConvert: unknown output bits per pixel?!");
+	// Hack for patches because you'll want to preserve transparency.
+	if (Picture_IsPatchFormat(outformat))
+		outbpp = 16;
+	else
+	{
+		outbpp = Picture_FormatBPP(outformat);
+		if (!outbpp)
+			I_Error("Picture_PNGConvert: unknown output bits per pixel?!");
+	}
 
 	// Figure out the size
 	flatsize = (width * height) * (outbpp / 8);
@@ -936,7 +942,9 @@ void *Picture_PNGConvert(
 		*outsize = flatsize;
 
 	// Convert the image
-	flat = Z_Malloc(flatsize, PU_STATIC, NULL);
+	flat = Z_Calloc(flatsize, PU_STATIC, NULL);
+
+	// Set transparency
 	if (outbpp == 8)
 		memset(flat, TRANSPARENTPIXEL, (width * height));
 
@@ -980,7 +988,7 @@ void *Picture_PNGConvert(
 		}
 	}
 
-	// Free the row pointers that libpng allocated.
+	// Free the row pointers that we allocated for libpng.
 	free(row_pointers);
 
 	// But wait, there's more!
@@ -990,7 +998,7 @@ void *Picture_PNGConvert(
 		pictureformat_t informat = PICFMT_NONE;
 		INT16 patleftoffset = 0, pattopoffset = 0;
 
-		// Figure out the input format, from the bitdepth of the input format
+		// Figure out the format of the flat, from the bit depth of the output format
 		switch (outbpp)
 		{
 			case 32:
@@ -1000,7 +1008,7 @@ void *Picture_PNGConvert(
 				informat = PICFMT_FLAT16;
 				break;
 			default:
-				informat = PICFMT_FLAT; // Assumed 8bpp
+				informat = PICFMT_FLAT;
 				break;
 		}
 
@@ -1016,6 +1024,7 @@ void *Picture_PNGConvert(
 		return converted;
 	}
 
+	// Return the converted flat!
 	return flat;
 }
 
diff --git a/src/r_plane.c b/src/r_plane.c
index c11aeb138..43c097a23 100644
--- a/src/r_plane.c
+++ b/src/r_plane.c
@@ -824,7 +824,7 @@ static UINT8 *R_GetTextureFlat(levelflat_t *levelflat, boolean leveltexture, boo
 			{
 				INT32 pngwidth, pngheight;
 
-				levelflat->flatpatch = Picture_PNGConvert(ds_source, PICFMT_FLAT32, &pngwidth, &pngheight, NULL, NULL, W_LumpLength(levelflat->u.flat.lumpnum), NULL, 0);
+				levelflat->flatpatch = Picture_PNGConvert(ds_source, PICFMT_FLAT, &pngwidth, &pngheight, NULL, NULL, W_LumpLength(levelflat->u.flat.lumpnum), NULL, 0);
 				levelflat->topoffset = levelflat->leftoffset = 0;
 				levelflat->width = (UINT16)pngwidth;
 				levelflat->height = (UINT16)pngheight;