PNG reading support, much thanks to DrSpliff

include/QF/Makefile.am

@@ -5,7 +5,7 @@ include_HEADERS = bspfile.h cbuf.h cdaudio.h checksum.h clip_hull.h cmd.h \
 	console.h crc.h csqc.h cvar.h dstring.h draw.h gib.h hash.h hl.h \
 	idparse.h in_event.h info.h input.h joystick.h keys.h link.h llist.h \
 	locs.h mathlib.h mdfour.h model.h modelgen.h msg.h pak.h pakfile.h \
-	pcx.h plugin.h pr_comp.h pr_debug.h pr_obj.h progs.h qargs.h qdefs.h \
-	qendian.h qfplist.h qtypes.h quakefs.h quakeio.h render.h riff.h \
+	pcx.h png.h plugin.h pr_comp.h pr_debug.h pr_obj.h progs.h qargs.h \
+	qdefs.h qendian.h qfplist.h qtypes.h quakefs.h quakeio.h render.h riff.h \
 	screen.h sizebuf.h skin.h sound.h spritegn.h sys.h teamplay.h texture.h \
 	tga.h uint32.h va.h ver_check.h vid.h view.h wad.h zone.h

include/QF/png.h

@@ -0,0 +1,3 @@
+#include "QF/quakefs.h"
+
+tex_t *LoadPNG (QFile *infile);

libs/image/Makefile.am

@@ -5,9 +5,9 @@ INCLUDES= -I$(top_srcdir)/include
 lib_LTLIBRARIES= libQFimage.la
 
 libQFimage_la_LDFLAGS=		-version-info 1:0:0
-libQFimage_la_LIBADD=		
+libQFimage_la_LIBADD=		-lpng
 libQFimage_la_DEPENDENCIES=
 libQFimage_la_SOURCES= \
-	pcx.c tga.c
+	pcx.c png.c tga.c
 
 EXTRA_DIST=

libs/image/png.c

@@ -0,0 +1,182 @@
+/*
+	png.c
+
+	PNG image handling
+
+	Copyright (C) 2003 Harry Roberts
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation; either version 2
+	of the License, or (at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+	See the GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to:
+
+		Free Software Foundation, Inc.
+		59 Temple Place - Suite 330
+		Boston, MA  02111-1307, USA
+
+*/
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+static __attribute__ ((unused)) const char rcsid[] = 
+	"$Id$";
+
+#ifdef HAVE_STRING_H
+# include <string.h>
+#endif
+#ifdef HAVE_STRINGS_H
+# include <strings.h>
+#endif
+
+#include "png.h"
+
+#include "QF/qendian.h"
+#include "QF/qtypes.h"
+#include "QF/quakefs.h"
+#include "QF/sys.h"
+#include "QF/texture.h"
+#include "QF/zone.h"
+
+#include "compat.h"
+#include "QF/png.h"
+
+typedef unsigned char	uch;
+typedef unsigned short	ush;
+typedef unsigned long	ulg;
+
+static png_structp png_ptr = NULL;
+static png_infop info_ptr = NULL;
+static QFile *pngfile = NULL;
+
+char tmpBuffer[8192];
+
+/* Qread wrapper for libpng */
+static void 
+user_read_data (png_structp png_ptr, png_bytep data, png_size_t length) {
+	Qread (pngfile, data, length);
+}
+
+/* Basicly taken from the libpng example rpng-x */
+static int
+readpng_init (QFile *infile)
+{
+	uch sig[8];
+
+	/* Check the signiture */
+	Qread (infile, sig, 8);
+	if (!png_check_sig(sig, 8)) {
+		Sys_Printf ("Bad png file\n");
+		return (1);
+	}
+
+	png_ptr = png_create_read_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	if (!png_ptr)
+		return (2); /* Out of memory! */
+
+	info_ptr = png_create_info_struct (png_ptr);
+	if (!info_ptr) {
+		png_destroy_read_struct (&png_ptr, NULL, NULL);
+		return (3); /* Out of memory! */
+	}
+
+	/* setjmp() must be called in every function that calls a PNG-reading
+	 * libpng function */
+
+	if (setjmp(png_jmpbuf(png_ptr))) {
+		png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+		return (4);
+	}
+	
+	pngfile = infile;
+	png_set_read_fn (png_ptr, tmpBuffer, user_read_data);
+	
+	/* Is png_set_sig_bytes needed? */
+	png_set_sig_bytes (png_ptr, 8); /* We allready read the 8 signiture bytes */
+
+	png_read_info (png_ptr, info_ptr); /* read all png info upto the image data */
+
+	return (0);
+}
+
+/* Load the png file and return a texture */
+tex_t *
+LoadPNG (QFile *infile)
+{
+	double gamma;
+	png_uint_32  i, rowbytes;
+	png_bytepp  row_pointers = NULL;
+	png_uint_32 width, height;
+	int bit_depth, color_type;
+	tex_t *tex;
+	
+	if (readpng_init(infile) != 0)
+		return (NULL);
+		
+	png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, NULL, NULL, NULL);
+	
+	if (color_type == PNG_COLOR_TYPE_PALETTE)
+		png_set_expand (png_ptr);
+	
+	if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
+		png_set_expand (png_ptr);
+		
+	if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
+		png_set_expand (png_ptr);
+		
+	if (bit_depth == 16)
+		png_set_strip_16 (png_ptr);
+	
+	if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
+		png_set_gray_to_rgb (png_ptr);
+	
+	/* NOTE: gamma support? */
+	/* unlike the example in the libpng documentation, we have *no* idea where
+	 * this file may have come from--so if it doesn't have a file gamma, don't
+	 * do any correction ("do no harm")
+	 */
+	if (png_get_gAMA(png_ptr, info_ptr, &gamma))
+		png_set_gamma (png_ptr, 1.0, gamma);
+
+	/* All transformations have been registered, now update the info_ptr structure */		
+	png_read_update_info (png_ptr, info_ptr);
+	
+	/* Allocate tex_t structure */
+	rowbytes = png_get_rowbytes(png_ptr, info_ptr);
+	tex = Hunk_TempAlloc (field_offset (tex_t, data[height * rowbytes]));	
+	
+	tex->width = width;
+	tex->height = height;
+	if (color_type & PNG_COLOR_MASK_ALPHA)
+		tex->format = tex_rgba;
+	else
+		tex->format = tex_rgb;
+	tex->palette = NULL;
+	
+	if ((row_pointers = (png_bytepp)malloc(height * sizeof(png_bytep))) == NULL) {
+		png_destroy_read_struct (&png_ptr, &info_ptr, NULL);
+		return (NULL); /* Out of memory */
+	}
+	
+	for (i = 0; i < height; ++i)
+		row_pointers[i] = tex->data + (i * rowbytes);
+		
+	/* Now we can go ahead and read the whole image */
+	png_read_image(png_ptr, row_pointers);
+	
+	free(row_pointers);
+	row_pointers = NULL;
+
+	png_read_end(png_ptr, NULL);
+		
+	return (tex);
+}