From 0750d273a6004ce73e9ce11f4b01c6eb7799b74e Mon Sep 17 00:00:00 2001
From: Jaime Passos <lazymyuutsu@gmail.com>
Date: Thu, 10 Sep 2020 03:16:21 -0300
Subject: [PATCH] Attempt to use the PNG image's palette, if it is present
---
src/r_picformats.c | 189 ++++++++++++++++++++++++++++++++++++++-------
1 file changed, 161 insertions(+), 28 deletions(-)
diff --git a/src/r_picformats.c b/src/r_picformats.c
index dbd090fc7..d48bbaaf2 100644
--- a/src/r_picformats.c
+++ b/src/r_picformats.c
@@ -798,13 +798,24 @@ static void PNG_warn(png_structp PNG, png_const_charp pngtext)
CONS_Debug(DBG_RENDER, "libpng warning at %p: %s", PNG, pngtext);
}
-static png_bytep *PNG_Read(const UINT8 *png, INT32 *w, INT32 *h, INT16 *topoffset, INT16 *leftoffset, size_t size)
+static png_bytep *PNG_Read(
+ const UINT8 *png,
+ INT32 *w, INT32 *h, INT16 *topoffset, INT16 *leftoffset,
+ boolean *use_palette, size_t size)
{
png_structp png_ptr;
png_infop png_info_ptr;
png_uint_32 width, height;
int bit_depth, color_type;
png_uint_32 y;
+
+ png_colorp palette;
+ int palette_size;
+
+ png_bytep trans;
+ int trans_num;
+ png_color_16p trans_values;
+
#ifdef PNG_SETJMP_SUPPORTED
#ifdef USE_FAR_KEYWORD
jmp_buf jmpbuf;
@@ -864,10 +875,48 @@ static png_bytep *PNG_Read(const UINT8 *png, INT32 *w, INT32 *h, INT16 *topoffse
if (bit_depth == 16)
png_set_strip_16(png_ptr);
+ palette = NULL;
+ *use_palette = false;
+
if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
png_set_gray_to_rgb(png_ptr);
else if (color_type == PNG_COLOR_TYPE_PALETTE)
- png_set_palette_to_rgb(png_ptr);
+ {
+ boolean usepal = false;
+
+ // Lactozilla: Check if the PNG has a palette, and if its color count
+ // matches the color count of SRB2's palette: 256 colors.
+ if (png_get_PLTE(png_ptr, png_info_ptr, &palette, &palette_size))
+ {
+ if (palette_size == 256)
+ usepal = true;
+ }
+
+ // If any of the tRNS colors have an alpha lower than 0xFF, and that
+ // color is present on the image, the palette flag is disabled.
+ png_get_tRNS(png_ptr, png_info_ptr, &trans, &trans_num, &trans_values);
+
+ if (trans_num == 256)
+ {
+ int i;
+ for (i = 0; i < trans_num; i++)
+ {
+ // libpng will transform this image into RGB even if
+ // the transparent index does not exist in the image,
+ // and there is no way around that.
+ if (trans[i] < 0xFF)
+ {
+ usepal = false;
+ break;
+ }
+ }
+ }
+
+ if (usepal)
+ *use_palette = true;
+ else
+ png_set_palette_to_rgb(png_ptr);
+ }
if (png_get_valid(png_ptr, png_info_ptr, PNG_INFO_tRNS))
png_set_tRNS_to_alpha(png_ptr);
@@ -908,6 +957,7 @@ static png_bytep *PNG_Read(const UINT8 *png, INT32 *w, INT32 *h, INT16 *topoffse
*w = (INT32)width;
*h = (INT32)height;
+
return row_pointers;
}
@@ -935,12 +985,17 @@ void *Picture_PNGConvert(
INT32 outbpp;
size_t flatsize;
png_uint_32 x, y;
- png_bytep *row_pointers = PNG_Read(png, w, h, topoffset, leftoffset, insize);
+ png_bytep row;
+ boolean palette = false;
+ png_bytep *row_pointers = PNG_Read(png, w, h, topoffset, leftoffset, &palette, insize);
png_uint_32 width = *w, height = *h;
if (png == NULL)
I_Error("Picture_PNGConvert: picture was NULL!");
+ if (row_pointers == NULL)
+ I_Error("Picture_PNGConvert: row_pointers was NULL!");
+
// Find the output format's bits per pixel amount
outbpp = Picture_FormatBPP(outformat);
@@ -973,43 +1028,119 @@ void *Picture_PNGConvert(
InitColorLUT(&png_colorlookup, pMasterPalette, false);
#endif
- for (y = 0; y < height; y++)
+ if (outbpp == PICDEPTH_32BPP)
{
- png_bytep row = row_pointers[y];
- for (x = 0; x < width; x++)
+ RGBA_t out;
+ UINT32 *outflat = (UINT32 *)flat;
+
+ if (palette)
{
- png_bytep px = &(row[x * 4]);
- if ((UINT8)px[3])
+ for (y = 0; y < height; y++)
{
- UINT8 red = (UINT8)px[0];
- UINT8 green = (UINT8)px[1];
- UINT8 blue = (UINT8)px[2];
- UINT8 alpha = (UINT8)px[3];
- if (outbpp == PICDEPTH_32BPP)
+ row = row_pointers[y];
+ for (x = 0; x < width; x++)
{
- UINT32 *outflat = (UINT32 *)flat;
- RGBA_t out;
- out.s.red = red;
- out.s.green = green;
- out.s.blue = blue;
- out.s.alpha = alpha;
+ out = V_GetColor(row[x]);
outflat[((y * width) + x)] = out.rgba;
}
- else
+ }
+ }
+ else
+ {
+ for (y = 0; y < height; y++)
+ {
+ row = row_pointers[y];
+ for (x = 0; x < width; x++)
{
+ png_bytep px = &(row[x * 4]);
+ if ((UINT8)px[3])
+ {
+ out.s.red = (UINT8)px[0];
+ out.s.green = (UINT8)px[1];
+ out.s.blue = (UINT8)px[2];
+ out.s.alpha = (UINT8)px[3];
+ outflat[((y * width) + x)] = out.rgba;
+ }
+ else
+ outflat[((y * width) + x)] = 0x00000000;
+ }
+ }
+ }
+ }
+ else if (outbpp == PICDEPTH_16BPP)
+ {
+ UINT16 *outflat = (UINT16 *)flat;
+
+ if (palette)
+ {
+ for (y = 0; y < height; y++)
+ {
+ row = row_pointers[y];
+ for (x = 0; x < width; x++)
+ outflat[((y * width) + x)] = (0xFF << 8) | row[x];
+ }
+ }
+ else
+ {
+ for (y = 0; y < height; y++)
+ {
+ row = row_pointers[y];
+ for (x = 0; x < width; x++)
+ {
+ png_bytep px = &(row[x * 4]);
+ UINT8 red = (UINT8)px[0];
+ UINT8 green = (UINT8)px[1];
+ UINT8 blue = (UINT8)px[2];
+ UINT8 alpha = (UINT8)px[3];
+
+ if (alpha)
+ {
#ifdef PICTURE_PNG_USELOOKUP
- UINT8 palidx = GetColorLUT(&png_colorlookup, red, green, blue);
+ UINT8 palidx = GetColorLUT(&png_colorlookup, red, green, blue);
#else
- UINT8 palidx = NearestColor(red, green, blue);
+ UINT8 palidx = NearestColor(red, green, blue);
#endif
- if (outbpp == PICDEPTH_16BPP)
- {
- UINT16 *outflat = (UINT16 *)flat;
- outflat[((y * width) + x)] = (alpha << 8) | palidx;
+ outflat[((y * width) + x)] = (0xFF << 8) | palidx;
}
- else // 8bpp
+ else
+ outflat[((y * width) + x)] = 0x0000;
+ }
+ }
+ }
+ }
+ else // 8bpp
+ {
+ UINT8 *outflat = (UINT8 *)flat;
+
+ if (palette)
+ {
+ for (y = 0; y < height; y++)
+ {
+ row = row_pointers[y];
+ for (x = 0; x < width; x++)
+ outflat[((y * width) + x)] = row[x];
+ }
+ }
+ else
+ {
+ for (y = 0; y < height; y++)
+ {
+ row = row_pointers[y];
+ for (x = 0; x < width; x++)
+ {
+ png_bytep px = &(row[x * 4]);
+ UINT8 red = (UINT8)px[0];
+ UINT8 green = (UINT8)px[1];
+ UINT8 blue = (UINT8)px[2];
+ UINT8 alpha = (UINT8)px[3];
+
+ if (alpha)
{
- UINT8 *outflat = (UINT8 *)flat;
+#ifdef PICTURE_PNG_USELOOKUP
+ UINT8 palidx = GetColorLUT(&png_colorlookup, red, green, blue);
+#else
+ UINT8 palidx = NearestColor(red, green, blue);
+#endif
outflat[((y * width) + x)] = palidx;
}
}
@@ -1018,6 +1149,8 @@ void *Picture_PNGConvert(
}
// Free the row pointers that we allocated for libpng.
+ for (y = 0; y < height; y++)
+ free(row_pointers[y]);
free(row_pointers);
// But wait, there's more!
--
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