From 9e217b256bd668298370d18645d23d4019c3968c Mon Sep 17 00:00:00 2001
From: Bradley Bell <btb@icculus.org>
Date: Sat, 22 May 2004 23:41:29 +0000
Subject: [PATCH] add opengl replacement texture support (requires libpng and
 zlib) (d1x r1.42, r1.1, r1.10, r1.4, r1.1)

---
 include/pngfile.h | 21 +++++++++++
 misc/Makefile.am  |  2 +
 misc/pngfile.c    | 94 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 117 insertions(+)
 create mode 100644 include/pngfile.h
 create mode 100644 misc/pngfile.c

diff --git a/include/pngfile.h b/include/pngfile.h
new file mode 100644
index 00000000..b457991e
--- /dev/null
+++ b/include/pngfile.h
@@ -0,0 +1,21 @@
+/* $Id: pngfile.h,v 1.1 2004-05-22 23:41:29 btb Exp $ */
+#ifndef PNGFILE_H
+#define PNGFILE_H
+
+typedef struct _png_data {
+	unsigned int width;
+	unsigned int height;
+	unsigned int depth;
+	unsigned int channels;
+	unsigned paletted:1;
+	unsigned color:1;
+	unsigned alpha:1;
+
+	unsigned char *data;
+	unsigned char *palette;
+	unsigned int num_palette;
+} png_data;
+
+extern int read_png(char *filename, png_data *pdata);
+
+#endif
diff --git a/misc/Makefile.am b/misc/Makefile.am
index d408cae1..4bda6d54 100644
--- a/misc/Makefile.am
+++ b/misc/Makefile.am
@@ -9,6 +9,8 @@ libmisc_a_SOURCES = ${PNG_SRCS} \
 args.c      error.c    strio.c \
 d_io.c      hash.c     strutil.c
 
+EXTRA_libmisc_a_SOURCES = pngfile.c
+
 # checker.c
 
 #checker.o: checker.c
diff --git a/misc/pngfile.c b/misc/pngfile.c
new file mode 100644
index 00000000..472d913e
--- /dev/null
+++ b/misc/pngfile.c
@@ -0,0 +1,94 @@
+/* $Id: pngfile.c,v 1.1 2004-05-22 23:41:29 btb Exp $ */
+#include <stdio.h>
+#include <png.h>
+
+#include "pngfile.h"
+#include "u_mem.h"
+#include "pstypes.h"
+
+int read_png(char *filename, png_data *pdata)
+{
+	ubyte header[8];
+	png_structp png_ptr = NULL;
+	png_infop info_ptr = NULL;
+	png_bytepp row_pointers = NULL;
+	png_uint_32 width, height;
+	int depth, color_type;
+	int i;
+	FILE *fp = NULL;
+
+	if (!filename || !pdata)
+		return 0;
+
+	if ((fp = fopen(filename, "rb")) == NULL)
+		return 0;
+
+	fread(header, 1, 8, fp);
+	if (!png_check_sig(header, 8))
+		return 0;
+
+	png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	info_ptr = png_create_info_struct(png_ptr);
+
+	pdata->data = pdata->palette = NULL;
+	pdata->num_palette = 0;
+	if (setjmp(png_ptr->jmpbuf))
+	{
+		png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
+		if (pdata->data)
+			free(pdata->data);
+		if (pdata->palette)
+			free(pdata->palette);
+		if (row_pointers)
+			free(row_pointers);
+		fclose(fp);
+		return 0;
+	}
+
+	png_init_io(png_ptr, fp);
+	png_set_sig_bytes(png_ptr, 8);
+	png_read_info(png_ptr, info_ptr);
+	png_get_IHDR(png_ptr, info_ptr, &width, &height, &depth, &color_type, NULL, NULL, NULL);
+
+	pdata->width = width;
+	pdata->height = height;
+	pdata->depth = depth;
+
+	pdata->data = (ubyte*)malloc(png_get_rowbytes(png_ptr, info_ptr) * height);
+	row_pointers = (png_bytep *)malloc(sizeof(png_bytep) * height);
+	for (i = 0; i < height; i++)
+		row_pointers[i] = &pdata->data[png_get_rowbytes(png_ptr, info_ptr) * i];
+
+	png_read_image(png_ptr, row_pointers);
+	free(row_pointers);
+	row_pointers=NULL;
+	png_read_end(png_ptr, info_ptr);
+
+	if (color_type == PNG_COLOR_TYPE_PALETTE)
+	{
+		png_colorp palette;
+
+		if (png_get_PLTE(png_ptr, info_ptr, &palette, &pdata->num_palette))
+		{
+			pdata->palette = (ubyte*)malloc(pdata->num_palette * 3);
+			memcpy(pdata->palette, palette, pdata->num_palette * 3);
+		}
+	}
+
+	pdata->paletted = (color_type & PNG_COLOR_MASK_PALETTE) > 0;
+	pdata->color = (color_type & PNG_COLOR_MASK_COLOR) > 0;
+	pdata->alpha = (color_type & PNG_COLOR_MASK_ALPHA) > 0;
+	if (pdata->color && pdata->alpha)
+		pdata->channels = 4;
+	else if (pdata->color && !pdata->alpha)
+		pdata->channels = 3;
+	else if (!pdata->color && pdata->alpha)
+		pdata->channels = 2;
+	else //if (!pdata->color && !pdata->alpha)
+		pdata->channels = 1;
+
+	png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
+	fclose(fp);
+
+	return 1;
+}
-- 
2.39.2