test: Remove custom read/write-png code in favor of using cairo surfaces

Also combine image_diff and image_diff_flattened into a single function

This was manually taken from 95475218858792ccb20ac6ad28db22e233c783d7
(It would have been a cherry-pick, but that doesn't yet handle file
renames.)

9 files changed, 117 insertions, 535 deletions

diff --git a/test/Makefile.am b/test/Makefile.am
index 32c43295a..9d4ea8b09 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -389,10 +389,6 @@ buffer-diff.c		\
 buffer-diff.h		\
 cairo-test.c		\
 cairo-test.h		\
-read-png.c		\
-read-png.h		\
-write-png.c		\
-write-png.h		\
 xmalloc.c		\
 xmalloc.h
 
diff --git a/test/buffer-diff.c b/test/buffer-diff.c
index ade0cc800..b59b5e898 100644
--- a/test/buffer-diff.c
+++ b/test/buffer-diff.c
@@ -39,8 +39,6 @@
 #include "cairo-test.h"
 
 #include "buffer-diff.h"
-#include "read-png.h"
-#include "write-png.h"
 #include "xmalloc.h"
 
 static void
@@ -143,71 +141,128 @@ buffer_diff_noalpha (unsigned char *buf_a,
 			    width, height, stride_a, stride_b, stride_diff, 0x00ffffff);
 }
 
+static cairo_status_t
+stdio_write_func (void *closure, const unsigned char *data, unsigned int length)
+{
+    FILE *file = closure;
+
+    if (fwrite (data, 1, length, file) != length)
+	return CAIRO_STATUS_WRITE_ERROR;
+
+    return CAIRO_STATUS_SUCCESS;
+}
+
+/* Flatten an ARGB surface by blending it over white. The resulting
+ * surface, (still in ARGB32 format, but with only alpha==1.0
+ * everywhere) is returned in the same surface pointer.
+ *
+ * The original surface will be destroyed.
+ *
+ * The (x,y) value specify an origin of interest for the original
+ * image. The flattened image will be generated only from the box
+ * extending from (x,y) to (width,height).
+ */
+static void
+flatten_surface (cairo_surface_t **surface, int x, int y)
+{
+    cairo_surface_t *flat;
+    cairo_t *cr;
+
+    flat = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+				       cairo_image_surface_get_width (*surface) - x,
+				       cairo_image_surface_get_height (*surface) - y);
+    cairo_surface_set_device_offset (flat, -x, -y);
+
+    cr = cairo_create (flat);
+    cairo_set_source_rgb (cr, 1, 1, 1);
+    cairo_paint (cr);
+    cairo_set_source_surface (cr, *surface, 0, 0);
+    cairo_paint (cr);
+    cairo_destroy (cr);
+
+    cairo_surface_destroy (*surface);
+    *surface = flat;
+}
+
 /* Image comparison code courtesy of Richard Worth <richard@theworths.org>
  * Returns number of pixels changed, (or -1 on error).
  * Also saves a "diff" image intended to visually show where the
  * images differ.
  */
-int
-image_diff (const char *filename_a,
-	    const char *filename_b,
-	    const char *filename_diff,
-	    int		ax,
-	    int		ay,
-	    int		bx,
-	    int		by)
+static int
+image_diff_core (const char *filename_a,
+		 const char *filename_b,
+		 const char *filename_diff,
+		 int		ax,
+		 int		ay,
+		 int		bx,
+		 int		by,
+		 cairo_bool_t	flatten)
 {
     int pixels_changed;
     unsigned int width_a, height_a, stride_a;
     unsigned int width_b, height_b, stride_b;
-    unsigned int stride_diff;
-    unsigned char *buf_a, *buf_b, *buf_diff;
-    read_png_status_t status;
+    cairo_surface_t *surface_a, *surface_b, *surface_diff;
 
-    status = read_png_argb32 (filename_a, &buf_a, &width_a, &height_a, &stride_a);
-    if (status)
+    surface_a = cairo_image_surface_create_from_png (filename_a);
+    if (cairo_surface_status (surface_a))
 	return -1;
 
-    status = read_png_argb32 (filename_b, &buf_b, &width_b, &height_b, &stride_b);
-    if (status) {
-	free (buf_a);
+    surface_b = cairo_image_surface_create_from_png (filename_b);
+    if (cairo_surface_status (surface_b)) {
+	cairo_surface_destroy (surface_a);
 	return -1;
     }
 
-    width_a -= ax;
-    height_a -= ay;
-    width_b -= bx;
-    height_b -= by;
+    width_a = cairo_image_surface_get_width (surface_a) - ax;
+    height_a = cairo_image_surface_get_height (surface_a) - ay;
+    width_b = cairo_image_surface_get_width (surface_b) - bx;
+    height_b = cairo_image_surface_get_height (surface_b) - by;
 
     if (width_a  != width_b  ||
 	height_a != height_b)
     {
-	cairo_test_log ("Error: Image size mismatch: (%dx%d@%d) vs. (%dx%d@%d)\n"
+	cairo_test_log ("Error: Image size mismatch: (%dx%d) vs. (%dx%d)\n"
 			"       for %s vs. %s\n",
-			width_a, height_a, stride_a,
-			width_b, height_b, stride_b,
+			width_a, height_a,
+			width_b, height_b,
 			filename_a, filename_b);
-	free (buf_a);
-	free (buf_b);
+	cairo_surface_destroy (surface_a);
+	cairo_surface_destroy (surface_b);
 	return -1;
     }
 
-    stride_diff = 4 * width_a;
-    buf_diff = xcalloc (stride_diff * height_a, 1);
+    if (flatten) {
+	flatten_surface (&surface_a, ax, ay);
+	flatten_surface (&surface_b, bx, by);
+	ax = ay = bx = by = 0;
+    }
+
+    surface_diff = cairo_image_surface_create (CAIRO_FORMAT_ARGB32,
+					       width_a, height_a);
 
-    pixels_changed = buffer_diff (buf_a + (ay * stride_a) + ax * 4,
-                                  buf_b + (by * stride_b) + by * 4,
-                                  buf_diff,
+    stride_a = cairo_image_surface_get_stride (surface_a);
+    stride_b = cairo_image_surface_get_stride (surface_b);
+
+    pixels_changed = buffer_diff (cairo_image_surface_get_data (surface_a)
+				  + (ay * stride_a) + ax * 4,
+                                  cairo_image_surface_get_data (surface_b)
+				  + (by * stride_b) + by * 4,
+                                  cairo_image_surface_get_data (surface_diff),
                                   width_a, height_a,
-				  stride_a, stride_b, stride_diff);
+				  stride_a, stride_b,
+				  cairo_image_surface_get_stride (surface_diff));
 
     if (pixels_changed) {
 	FILE *png_file;
+
 	if (filename_diff)
 	    png_file = fopen (filename_diff, "wb");
 	else
 	    png_file = stdout;
-	write_png_argb32 (buf_diff, png_file, width_a, height_a, stride_diff);
+
+	cairo_surface_write_to_png_stream (surface_diff, stdio_write_func, png_file);
+
 	if (png_file != stdout)
 	    fclose (png_file);
     } else {
@@ -215,25 +270,27 @@ image_diff (const char *filename_a,
 	    xunlink (filename_diff);
     }
 
-    free (buf_a);
-    free (buf_b);
-    free (buf_diff);
+    cairo_surface_destroy (surface_a);
+    cairo_surface_destroy (surface_b);
+    cairo_surface_destroy (surface_diff);
 
     return pixels_changed;
 }
 
-/* Like image_diff, but first "flatten" the contents of filename_b by
- * blending over white.
- *
- * Yes, this is an ugly copy-and-paste of another function. I'm doing
- * this for two reasons:
- *
- * 1) I want to rewrite all of the image_diff interfaces anyway
- *    (should use cairo_image_surface_create_from_png, should save
- *    loaded buffers for re-use).
- *
- * 2) There is a second reason no more.
- */
+int
+image_diff (const char *filename_a,
+	    const char *filename_b,
+	    const char *filename_diff,
+	    int		ax,
+	    int		ay,
+	    int		bx,
+	    int		by)
+{
+    return image_diff_core (filename_a, filename_b, filename_diff,
+			    ax, ay, bx, by,
+			    FALSE);
+}
+
 int
 image_diff_flattened (const char *filename_a,
 		      const char *filename_b,
@@ -243,106 +300,7 @@ image_diff_flattened (const char *filename_a,
 		      int	  bx,
 		      int	  by)
 {
-    int pixels_changed;
-    unsigned int width_a, height_a, stride_a;
-    unsigned int width_b, height_b, stride_b;
-    unsigned char *buf_a, *buf_b, *buf_diff;
-    unsigned char *a_flat, *b_flat;
-    cairo_surface_t *buf_a_surface, *a_flat_surface;
-    cairo_surface_t *buf_b_surface, *b_flat_surface;
-    cairo_t *cr;
-    read_png_status_t status;
-
-    status = read_png_argb32 (filename_a, &buf_a, &width_a, &height_a, &stride_a);
-    if (status)
-	return -1;
-
-    status = read_png_argb32 (filename_b, &buf_b, &width_b, &height_b, &stride_b);
-    if (status) {
-	free (buf_a);
-	return -1;
-    }
-
-    width_a -= ax;
-    height_a -= ay;
-    width_b -= bx;
-    height_b -= by;
-
-    if (width_a  != width_b  ||
-	height_a != height_b)
-    {
-	cairo_test_log ("Error: Image size mismatch: (%dx%d@%d) vs. (%dx%d@%d)\n"
-			"       for %s vs. %s\n",
-			width_a, height_a, stride_a,
-			width_b, height_b, stride_b,
-			filename_a, filename_b);
-	free (buf_a);
-	free (buf_b);
-	return -1;
-    }
-
-    buf_a_surface =  cairo_image_surface_create_for_data (buf_a,
-							  CAIRO_FORMAT_ARGB32,
-							  width_a + ax, height_a + ay,
-							  stride_a);
-    buf_b_surface =  cairo_image_surface_create_for_data (buf_b,
-							  CAIRO_FORMAT_ARGB32,
-							  width_b + bx, height_b + by,
-							  stride_b);
-
-    buf_diff = xcalloc (stride_a * height_a, 1);
-
-    a_flat = xcalloc (stride_a * height_a, 1);
-    b_flat = xcalloc (stride_b * height_b, 1);
-
-    a_flat_surface = cairo_image_surface_create_for_data (a_flat,
-							  CAIRO_FORMAT_ARGB32,
-							  width_a, height_a,
-							  stride_a);
-    cairo_surface_set_device_offset (a_flat_surface, -ax, -ay);
-    b_flat_surface = cairo_image_surface_create_for_data (b_flat,
-							  CAIRO_FORMAT_ARGB32,
-							  width_b, height_b,
-							  stride_b);
-    cairo_surface_set_device_offset (b_flat_surface, -bx, -by);
-
-    cr = cairo_create (a_flat_surface);
-    cairo_set_source_rgb (cr, 1, 1, 1);
-    cairo_paint (cr);
-    cairo_set_source_surface (cr, buf_a_surface, 0, 0);
-    cairo_paint (cr);
-    cairo_destroy (cr);
-    cairo_surface_destroy (a_flat_surface);
-    cairo_surface_destroy (buf_a_surface);
-
-    cr = cairo_create (b_flat_surface);
-    cairo_set_source_rgb (cr, 1, 1, 1);
-    cairo_paint (cr);
-    cairo_set_source_surface (cr, buf_b_surface, 0, 0);
-    cairo_paint (cr);
-    cairo_destroy (cr);
-    cairo_surface_destroy (b_flat_surface);
-    cairo_surface_destroy (buf_b_surface);
-
-    pixels_changed = buffer_diff (a_flat,
-                                  b_flat,
-                                  buf_diff,
-				  width_a, height_a,
-                                  stride_a, stride_b, stride_a);
-
-    if (pixels_changed) {
-	FILE *png_file = fopen (filename_diff, "wb");
-	write_png_argb32 (buf_diff, png_file, width_a, height_a, stride_a);
-	fclose (png_file);
-    } else {
-	xunlink (filename_diff);
-    }
-
-    free (buf_a);
-    free (buf_b);
-    free (a_flat);
-    free (b_flat);
-    free (buf_diff);
-
-    return pixels_changed;
+    return image_diff_core (filename_a, filename_b, filename_diff,
+			    ax, ay, bx, by,
+			    TRUE);
 }
diff --git a/test/cairo-test.c b/test/cairo-test.c
index bf52f8af3..3eb554511 100644
--- a/test/cairo-test.c
+++ b/test/cairo-test.c
@@ -1,5 +1,5 @@
 /*
- * Copyright © 2004 Red Hat, Inc.
+ * Copyright © 2004,2006 Red Hat, Inc.
  *
  * Permission to use, copy, modify, distribute, and sell this software
  * and its documentation for any purpose is hereby granted without
@@ -48,8 +48,6 @@
 #include "cairo-test.h"
 
 #include "buffer-diff.h"
-#include "read-png.h"
-#include "write-png.h"
 #include "xmalloc.h"
 
 /* This is copied from cairoint.h. That makes it painful to keep in
diff --git a/test/cairo-test.h b/test/cairo-test.h
index 4f430acdb..83b43d073 100644
--- a/test/cairo-test.h
+++ b/test/cairo-test.h
@@ -143,6 +143,13 @@ cairo_test_paint_checkered (cairo_t *cr);
 void
 xasprintf (char **strp, const char *fmt, ...) CAIRO_PRINTF_FORMAT(2, 3);
 
+#ifndef FALSE
+#define FALSE 0
+#endif
+#ifndef TRUE
+#define TRUE !FALSE
+#endif
+
 CAIRO_END_DECLS
 
 #endif
diff --git a/test/imagediff.c b/test/imagediff.c
index d030e76e9..903087745 100644
--- a/test/imagediff.c
+++ b/test/imagediff.c
@@ -27,8 +27,6 @@
 #include <stdlib.h>
 
 #include "buffer-diff.h"
-#include "read-png.h"
-#include "write-png.h"
 #include "xmalloc.h"
 
 int
diff --git a/test/read-png.c b/test/read-png.c
deleted file mode 100644
index bb02e50b9..000000000
--- a/test/read-png.c
+++ /dev/null
@@ -1,196 +0,0 @@
-/*
- * Copyright © 2003 USC, Information Sciences Institute
- *
- * Permission to use, copy, modify, distribute, and sell this software
- * and its documentation for any purpose is hereby granted without
- * fee, provided that the above copyright notice appear in all copies
- * and that both that copyright notice and this permission notice
- * appear in supporting documentation, and that the name of the
- * University of Southern California not be used in advertising or
- * publicity pertaining to distribution of the software without
- * specific, written prior permission. The University of Southern
- * California makes no representations about the suitability of this
- * software for any purpose.  It is provided "as is" without express
- * or implied warranty.
- *
- * THE UNIVERSITY OF SOUTHERN CALIFORNIA DISCLAIMS ALL WARRANTIES WITH
- * REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL THE UNIVERSITY OF
- * SOUTHERN CALIFORNIA BE LIABLE FOR ANY SPECIAL, INDIRECT OR
- * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
- * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
- * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- *
- * Author: Carl D. Worth <cworth@isi.edu>
- */
-
-#if HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#if   HAVE_STDINT_H
-# include <stdint.h>
-#elif HAVE_INTTYPES_H
-# include <inttypes.h>
-#elif HAVE_SYS_INT_TYPES_H
-# include <sys/int_types.h>
-#elif defined(_MSC_VER)
-  typedef __int8 int8_t;
-  typedef unsigned __int8 uint8_t;
-  typedef __int16 int16_t;
-  typedef unsigned __int16 uint16_t;
-  typedef __int32 int32_t;
-  typedef unsigned __int32 uint32_t;
-  typedef __int64 int64_t;
-  typedef unsigned __int64 uint64_t;
-# ifndef HAVE_UINT64_T
-#  define HAVE_UINT64_T 1
-# endif
-#else
-#error Cannot find definitions for fixed-width integral types (uint8_t, uint32_t, etc.)
-#endif
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <png.h>
-
-#include "cairo-test.h"
-#include "read-png.h"
-#include "xmalloc.h"
-
-static void
-premultiply_data (png_structp   png,
-                  png_row_infop row_info,
-                  png_bytep     data)
-{
-    size_t i;
-
-    for (i = 0; i < row_info->rowbytes; i += 4) {
-	uint8_t *base = &data[i];
-	uint8_t  blue = base[0];
-	uint8_t  green = base[1];
-	uint8_t  red = base[2];
-	uint8_t  alpha = base[3];
-	uint32_t p;
-
-	red = ((unsigned) red * (unsigned) alpha + 127) / 255;
-	green = ((unsigned) green * (unsigned) alpha + 127) / 255;
-	blue = ((unsigned) blue * (unsigned) alpha + 127) / 255;
-	p = (alpha << 24) | (red << 16) | (green << 8) | (blue << 0);
-	memcpy (base, &p, sizeof (uint32_t));
-    }
-}
-
-read_png_status_t
-read_png_argb32 (const char         *filename,
-		 unsigned char      **data,
-		 unsigned int       *width,
-		 unsigned int       *height,
-		 unsigned int	    *stride)
-{
-    size_t i;
-    FILE *file;
-#define PNG_SIG_SIZE 8
-    unsigned char png_sig[PNG_SIG_SIZE];
-    int sig_bytes;
-    png_struct *png;
-    png_info *info;
-    png_uint_32 png_width, png_height;
-    int depth, color_type, interlace;
-    unsigned int pixel_size;
-    png_byte **row_pointers;
-
-    file = fopen (filename, "rb");
-    if (file == NULL) {
-	cairo_test_log ("Error: File not found: %s\n", filename);
-	return READ_PNG_FILE_NOT_FOUND;
-    }
-
-    sig_bytes = fread (png_sig, 1, PNG_SIG_SIZE, file);
-    if (png_check_sig (png_sig, sig_bytes) == 0) {
-        fclose (file);
-	cairo_test_log ("Error: File is not a PNG image: %s\n", filename);
-	return READ_PNG_FILE_NOT_PNG;
-    }
-
-    /* XXX: Perhaps we'll want some other error handlers? */
-    png = png_create_read_struct (PNG_LIBPNG_VER_STRING,
-                                  NULL,
-                                  NULL,
-                                  NULL);
-    if (png == NULL) {
-        fclose (file);
-	cairo_test_log ("Error: Out of memory while reading %s\n", filename);
-	return READ_PNG_NO_MEMORY;
-    }
-
-    info = png_create_info_struct (png);
-    if (info == NULL) {
-        fclose (file);
-        png_destroy_read_struct (&png, NULL, NULL);
-	cairo_test_log ("Error: Out of memory while reading %s\n", filename);
-	return READ_PNG_NO_MEMORY;
-    }
-
-    png_init_io (png, file);
-    png_set_sig_bytes (png, sig_bytes);
-
-    png_read_info (png, info);
-
-    png_get_IHDR (png, info,
-                  &png_width, &png_height, &depth,
-                  &color_type, &interlace, NULL, NULL);
-    *width = png_width;
-    *height = png_height;
-    *stride = 4 * png_width;
-
-    /* convert palette/gray image to rgb */
-    if (color_type == PNG_COLOR_TYPE_PALETTE)
-        png_set_palette_to_rgb (png);
-
-    /* expand gray bit depth if needed */
-    if (color_type == PNG_COLOR_TYPE_GRAY && depth < 8)
-        png_set_gray_1_2_4_to_8 (png);
-    /* transform transparency to alpha */
-    if (png_get_valid(png, info, PNG_INFO_tRNS))
-        png_set_tRNS_to_alpha (png);
-
-    if (depth == 16)
-        png_set_strip_16 (png);
-
-    if (depth < 8)
-        png_set_packing (png);
-
-    /* convert grayscale to RGB */
-    if (color_type == PNG_COLOR_TYPE_GRAY
-        || color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
-        png_set_gray_to_rgb (png);
-
-    if (interlace != PNG_INTERLACE_NONE)
-        png_set_interlace_handling (png);
-
-    png_set_bgr (png);
-    png_set_filler (png, 0xff, PNG_FILLER_AFTER);
-
-    png_set_read_user_transform_fn (png, premultiply_data);
-
-    png_read_update_info (png, info);
-
-    pixel_size = 4;
-    *data = xmalloc (png_width * png_height * pixel_size);
-
-    row_pointers = malloc (png_height * sizeof(char *));
-    for (i=0; i < png_height; i++)
-        row_pointers[i] = (png_byte *) (*data + i * png_width * pixel_size);
-
-    png_read_image (png, row_pointers);
-    png_read_end (png, info);
-
-    free (row_pointers);
-    fclose (file);
-
-    png_destroy_read_struct (&png, &info, NULL);
-
-    return READ_PNG_SUCCESS;
-}
diff --git a/test/read-png.h b/test/read-png.h
deleted file mode 100644
index 9c9ba433d..000000000
--- a/test/read-png.h
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- * Copyright © 2003 USC, Information Sciences Institute
- *
- * Permission to use, copy, modify, distribute, and sell this software
- * and its documentation for any purpose is hereby granted without
- * fee, provided that the above copyright notice appear in all copies
- * and that both that copyright notice and this permission notice
- * appear in supporting documentation, and that the name of the
- * University of Southern California not be used in advertising or
- * publicity pertaining to distribution of the software without
- * specific, written prior permission. The University of Southern
- * California makes no representations about the suitability of this
- * software for any purpose.  It is provided "as is" without express
- * or implied warranty.
- *
- * THE UNIVERSITY OF SOUTHERN CALIFORNIA DISCLAIMS ALL WARRANTIES WITH
- * REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL THE UNIVERSITY OF
- * SOUTHERN CALIFORNIA BE LIABLE FOR ANY SPECIAL, INDIRECT OR
- * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
- * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
- * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- *
- * Author: Carl D. Worth <cworth@isi.edu>
- */
-
-#ifndef READ_PNG_H
-#define READ_PNG_H
-
-typedef enum {
-    READ_PNG_SUCCESS = 0,
-    READ_PNG_FILE_NOT_FOUND,
-    READ_PNG_FILE_NOT_PNG,
-    READ_PNG_NO_MEMORY
-} read_png_status_t;
-
-read_png_status_t
-read_png_argb32 (const char         *filename,
-		 unsigned char      **data,
-		 unsigned int       *width,
-		 unsigned int       *height,
-		 unsigned int	    *stride);
-
-#endif
diff --git a/test/write-png.c b/test/write-png.c
deleted file mode 100644
index c906df5fa..000000000
--- a/test/write-png.c
+++ /dev/null
@@ -1,99 +0,0 @@
-/*
- * Copyright © 2003 USC, Information Sciences Institute
- *
- * Permission to use, copy, modify, distribute, and sell this software
- * and its documentation for any purpose is hereby granted without
- * fee, provided that the above copyright notice appear in all copies
- * and that both that copyright notice and this permission notice
- * appear in supporting documentation, and that the name of the
- * University of Southern California not be used in advertising or
- * publicity pertaining to distribution of the software without
- * specific, written prior permission. The University of Southern
- * California makes no representations about the suitability of this
- * software for any purpose.  It is provided "as is" without express
- * or implied warranty.
- *
- * THE UNIVERSITY OF SOUTHERN CALIFORNIA DISCLAIMS ALL WARRANTIES WITH
- * REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL THE UNIVERSITY OF
- * SOUTHERN CALIFORNIA BE LIABLE FOR ANY SPECIAL, INDIRECT OR
- * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
- * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
- * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- *
- * Author: Carl D. Worth <cworth@cworth.org>
- */
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <png.h>
-
-#include "write-png.h"
-
-static void
-unpremultiply_data (png_structp png, png_row_infop row_info, png_bytep data)
-{
-    size_t i;
-
-    for (i = 0; i < row_info->rowbytes; i += 4) {
-        unsigned char *b = &data[i];
-        unsigned int pixel;
-        unsigned char alpha;
-
-	memcpy (&pixel, b, sizeof (unsigned int));
-	alpha = (pixel & 0xff000000) >> 24;
-        if (alpha == 0) {
-	    b[0] = b[1] = b[2] = b[3] = 0;
-	} else {
-            b[0] = (((pixel & 0x0000ff) >>  0) * 255 + alpha / 2) / alpha;
-            b[1] = (((pixel & 0x00ff00) >>  8) * 255 + alpha / 2) / alpha;
-            b[2] = (((pixel & 0xff0000) >> 16) * 255 + alpha / 2) / alpha;
-	    b[3] = alpha;
-	}
-    }
-}
-
-void
-write_png_argb32 (unsigned char *buffer, FILE *file,
-		  int width, int height, int stride)
-{
-    int i;
-    png_struct *png;
-    png_info *info;
-    png_byte **rows;
-    png_color_16 white;
-
-    rows = malloc (height * sizeof(png_byte*));
-
-    for (i = 0; i < height; i++) {
-	rows[i] = buffer + i * stride;
-    }
-
-    png = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
-    info = png_create_info_struct (png);
-
-    png_init_io (png, file);
-    png_set_IHDR (png, info,
-		  width, height, 8,
-		  PNG_COLOR_TYPE_RGB_ALPHA,
-		  PNG_INTERLACE_NONE,
-		  PNG_COMPRESSION_TYPE_DEFAULT,
-		  PNG_FILTER_TYPE_DEFAULT);
-
-    white.red = 0xff;
-    white.blue = 0xff;
-    white.green = 0xff;
-    png_set_bKGD (png, info, &white);
-
-    png_set_write_user_transform_fn (png, unpremultiply_data);
-    png_set_bgr (png);
-
-    png_write_info (png, info);
-    png_write_image (png, rows);
-    png_write_end (png, info);
-
-    png_destroy_write_struct (&png, &info);
-
-    free (rows);
-}
diff --git a/test/write-png.h b/test/write-png.h
deleted file mode 100644
index 8074666a3..000000000
--- a/test/write-png.h
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright © 2003 USC, Information Sciences Institute
- *
- * Permission to use, copy, modify, distribute, and sell this software
- * and its documentation for any purpose is hereby granted without
- * fee, provided that the above copyright notice appear in all copies
- * and that both that copyright notice and this permission notice
- * appear in supporting documentation, and that the name of the
- * University of Southern California not be used in advertising or
- * publicity pertaining to distribution of the software without
- * specific, written prior permission. The University of Southern
- * California makes no representations about the suitability of this
- * software for any purpose.  It is provided "as is" without express
- * or implied warranty.
- *
- * THE UNIVERSITY OF SOUTHERN CALIFORNIA DISCLAIMS ALL WARRANTIES WITH
- * REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL THE UNIVERSITY OF
- * SOUTHERN CALIFORNIA BE LIABLE FOR ANY SPECIAL, INDIRECT OR
- * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
- * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
- * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- *
- * Author: Carl D. Worth <cworth@isi.edu>
- */
-
-#ifndef WRITE_PNG_H
-#define WRITE_PNG_H
-
-void
-write_png_argb32 (unsigned char *buffer, FILE * file,
-		  int width, int height, int stride);
-
-#endif