/* -*- Mode: C; c-basic-offset: 2; -*- */
/* GdkPixbuf library - test loaders
*
* Copyright (C) 2016 Martin Guy <martinwguy@gmail.com>
*
* 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, see <http://www.gnu.org/licenses/>.
*/
/*
* Test the two-step scaler speed optimization in gdk-pixbuf/pixops.c
* for result correctness. See https://bugzilla.gnome.org/show_bug.cgi?id=80925
*
* The two-step scaler kicks in when ceil(1/scale_x + 1) * ceil(1/scale_y + 1)
* (the number of 2KB filters created by make_filter_table()) exceeds 1000 so
* test cases wanting it have to do drastic image reductions, such as reducing
* both dimensions by a factor of more that sqrt(1000) - say by 40 both ways.
*
* There is a global boolean in the two-step-scaler allowing us to disable the
* two-step optimization to be able to compare the results with and without it.
*/
#include "config.h"
#include "gdk-pixbuf/gdk-pixbuf.h"
#include "test-common.h"
/* Size of images to be scaled */
#define SOURCE_WIDTH 400
#define SOURCE_HEIGHT 400
/* To trigger the two-step scaler, we need to reduce the total area by
* more than 1000. 40x40 is 1600. */
#define SCALE_FACTOR (1.0/40.0)
/* First, some functions to make test images */
/*
* pixdata_almost_equal(): A helper function to check whether the pixels in
* two images are almost the same: pixel color values are allowed to differ
* by at most one.
*/
/* Are two values the same or differ by one? */
#define within_one(a, b) \
((a) == (b) || (a) == (b) + 1 || (a) + 1 == (b))
static gboolean
pixdata_almost_equal (GdkPixbuf *one, GdkPixbuf *two)
{
guchar *one_row; /* Pointer to start of row of pixels in one */
guchar *one_pixel; /* Pointer to current pixel data in one */
guchar *two_row; /* Pointer to start of row of pixels in two */
guchar *two_pixel; /* Pointer to current pixel data in two */
guint x, y;
gint width_one, height_one;
width_one = gdk_pixbuf_get_width (one);
height_one = gdk_pixbuf_get_height (one);
g_assert_cmpint (height_one, >=, 0);
g_assert_cmpint (width_one, >=, 0);
g_assert_cmpint (gdk_pixbuf_get_height (two), >=, 0);
g_assert_cmpint (gdk_pixbuf_get_width (two), >=, 0);
if (width_one != gdk_pixbuf_get_width (two) ||
height_one != gdk_pixbuf_get_height (two))
{
g_test_fail();
}
for (y = 0, one_row = gdk_pixbuf_get_pixels (one),
two_row = gdk_pixbuf_get_pixels (two);
y < height_one;
y++, one_row += gdk_pixbuf_get_rowstride (one),
two_row += gdk_pixbuf_get_rowstride (two))
{
for (x = 0, one_pixel = one_row, two_pixel = two_row;
x < width_one;
x++, one_pixel += gdk_pixbuf_get_n_channels (one),
two_pixel += gdk_pixbuf_get_n_channels (two))
{
if (!(within_one(one_pixel[0], two_pixel[0]) &&
within_one(one_pixel[1], two_pixel[1]) &&
within_one(one_pixel[2], two_pixel[2])))
{
return FALSE;
}
}
}
return TRUE;
}
/* Create a checkerboard of (1,1,1) and (255,255,255) pixels and
* scale it to one fortieth of the image dimensions.
* See if the results are similar enough with and without the two-step
* optimization. */
static void
test_old_and_new (gconstpointer data)
{
GdkInterpType interp_type = *(GdkInterpType *) data;
const GdkPixbuf *source; /* Source image */
gint width = SOURCE_WIDTH; /* Size of source image */
gint height = SOURCE_HEIGHT;
GdkPixbuf *one; /* Version scaled by the old code */
GdkPixbuf *two; /* Version scaled in two steps */
/* Use an extreme source image, checkerboard, to exacerbate any artifacts */
source = make_checkerboard (width, height);
/* Scale it without and with the two-step optimization */
g_setenv ("GDK_PIXBUF_DISABLE_TWO_STEP_SCALER", "1", TRUE);
one = gdk_pixbuf_scale_simple (source,
(int) (width * SCALE_FACTOR + 0.5),
(int) (height * SCALE_FACTOR + 0.5),
interp_type);
g_unsetenv("GDK_PIXBUF_DISABLE_TWO_STEP_SCALER");
two = gdk_pixbuf_scale_simple (source,
(int) (width * SCALE_FACTOR + 0.5),
(int) (height * SCALE_FACTOR + 0.5),
interp_type);
/* Check that the results are almost the same. An error of one color value
* is admissible because the intermediate image's color values are stored
* in 8-bit color values. In practice, with the checkerboard pattern all
* pixels are (129,129,129) with the two-step scaler instead of (128,128,128)
* while the rg pattern gives identical results.
*/
if (!pixdata_almost_equal(one, two))
g_test_fail();
g_object_unref (G_OBJECT (one));
g_object_unref (G_OBJECT (two));
g_object_unref (G_OBJECT (source));
}
/* Crop a region out of a scaled image using gdk_pixbuf_new_subpixbuf() on a
* scaled image and by cropping it as part of the scaling, and check that the
* results are identical. */
static void
crop_n_compare(const GdkPixbuf *source, /* The source image */
double scale_factor, /* is scaled by this amount */
gint offset_x, /* and from this offset in the scaled image */
gint offset_y,
gint width, /* a region of this size is cropped out */
gint height,
GdkInterpType interp_type)
{
GdkPixbuf *whole_scaled; /* The whole image scaled but not cropped */
GdkPixbuf *cropped; /* The scaled-then-cropped result */
GdkPixbuf *scaled; /* The cropped-while-scaled result */
guint new_width, new_height; /* Size of whole scaled image */
/* First, scale the whole image and crop it */
new_width = (int) (gdk_pixbuf_get_width (source) * scale_factor + 0.5);
new_height = (int) (gdk_pixbuf_get_height (source) * scale_factor + 0.5);
g_assert_cmpint (new_width, ==, 10);
g_assert_cmpint (new_height, ==, 10);
whole_scaled = gdk_pixbuf_scale_simple (source, new_width, new_height, interp_type);
g_assert_nonnull (whole_scaled);
cropped = gdk_pixbuf_new_subpixbuf (whole_scaled, offset_x, offset_y, width, height);
g_assert_nonnull (cropped);
/* Now crop and scale it in one go */
scaled = gdk_pixbuf_new (GDK_COLORSPACE_RGB, 0, 8, width, height);
g_assert_nonnull (scaled);
gdk_pixbuf_scale (source, scaled,
0, 0, /* dest_[xy] */
width, height, /* dest_width/height */
-1.0 * offset_x, -1.0 * offset_y,
scale_factor, scale_factor,
interp_type);
/* and check that the results are the same.
* We can't use pixdata_equal() because it fails if rowstride is different
* and gdk_pixbuf_new_subpixbuf() reuses whole_scaled's image data with its
* larger rowstride. */
{
guchar *scaled_row; /* Pointer to start of row of pixels in scaled */
guchar *scaled_pixel; /* Pointer to current pixel data in scaled */
guchar *cropped_row; /* Pointer to start of row of pixels in cropped */
guchar *cropped_pixel; /* Pointer to current pixel data in cropped */
guint x, y;
gint scaled_width, scaled_height;
scaled_width = gdk_pixbuf_get_width (scaled);
scaled_height = gdk_pixbuf_get_height (scaled);
g_assert (scaled_width > 0);
g_assert (scaled_height > 0);
if (scaled_width != gdk_pixbuf_get_width (cropped) ||
scaled_height != gdk_pixbuf_get_height (cropped))
{
g_test_fail();
}
for (y = 0, scaled_row = gdk_pixbuf_get_pixels (scaled),
cropped_row = gdk_pixbuf_get_pixels (cropped);
y < scaled_height;
y++, scaled_row += gdk_pixbuf_get_rowstride (scaled),
cropped_row += gdk_pixbuf_get_rowstride (cropped))
{
for (x = 0, scaled_pixel = scaled_row, cropped_pixel = cropped_row;
x < scaled_width;
x++, scaled_pixel += gdk_pixbuf_get_n_channels (scaled),
cropped_pixel += gdk_pixbuf_get_n_channels (cropped))
{
if (!(scaled_pixel[0] == cropped_pixel[0] &&
scaled_pixel[1] == cropped_pixel[1] &&
scaled_pixel[2] == cropped_pixel[2]))
{
g_test_fail();
}
}
}
}
g_object_unref (G_OBJECT (whole_scaled));
g_object_unref (G_OBJECT (cropped));
g_object_unref (G_OBJECT (scaled));
}
/* Check that offsets work.
* We should be able to crop a region of an image using the scaler using
* negative offsets. */
static void
test_offset (gconstpointer data)
{
GdkInterpType interp_type = *(GdkInterpType *) data;
const GdkPixbuf *source; /* Source image */
gint swidth = SOURCE_WIDTH; /* Size of source image */
gint sheight = SOURCE_HEIGHT;
gint dwidth = (swidth * SCALE_FACTOR + 0.5); /* Size of scaled image */
gint dheight = (sheight * SCALE_FACTOR + 0.5);
source = make_rg (swidth, sheight);
/* Check that the scaler correctly crops out an image half the size of the
* original from each corner and from the middle */
crop_n_compare (source, SCALE_FACTOR, 0, 0, dwidth / 2, dheight / 2, interp_type);
crop_n_compare (source, SCALE_FACTOR, 0, dheight / 2, dwidth / 2, dheight / 2, interp_type);
crop_n_compare (source, SCALE_FACTOR, dwidth / 2, 0, dwidth / 2, dheight / 2, interp_type);
crop_n_compare (source, SCALE_FACTOR, dwidth / 2, dheight / 2, dwidth / 2, dheight / 2, interp_type);
crop_n_compare (source, SCALE_FACTOR, dwidth / 4, dheight / 4, dwidth / 2, dheight / 2, interp_type);
g_object_unref (G_OBJECT (source));
}
/* Test the dest_x and dest_y fields by making a copy of an image by
* scaling 1:1 and using dest to copy the four quadrants separately.
*
* When scaled, images are:
* 1) scaled by the scale factors with respect to the top-left corner
* 2) translated by the offsets (negative to shift the image left/up in its
* frame)
* 3) a region of size dest_width x dest-height starting at (dest_x,dest_y)
* in the scaled-and-offset image is copied to (dest_x,dest_y) in the
* destination image. See the illustration at
* https://developer.gnome.org/gdk-pixbuf/2.22/gdk-pixbuf-scaling.html#gdk-pixbuf-composite */
static void
test_dest (gconstpointer data)
{
GdkInterpType interp_type = *(GdkInterpType *) data;
const GdkPixbuf *source; /* Source image */
GdkPixbuf *scaled; /* Scaled whole image */
GdkPixbuf *copy; /* Destination image */
gint swidth = SOURCE_WIDTH; /* Size of source image */
gint sheight = SOURCE_HEIGHT;
gint dwidth = swidth * SCALE_FACTOR; /* Size of scaled image */
gint dheight = sheight * SCALE_FACTOR;
source = make_checkerboard (swidth, sheight);
copy = gdk_pixbuf_new (GDK_COLORSPACE_RGB, 0, 8, dwidth, dheight);
g_assert_nonnull (copy);
/* Copy the four quadrants separately */
gdk_pixbuf_scale ((const GdkPixbuf *) source, copy,
0, 0, /* dest_[xy] */
dwidth / 2, dheight / 2, /* dest_width/height */
0.0, 0.0, /* offset_[xy] */
SCALE_FACTOR, SCALE_FACTOR,
interp_type);
gdk_pixbuf_scale ((const GdkPixbuf *) source, copy,
dwidth / 2, 0, /* dest_[xy] */
dwidth / 2, dheight / 2, /* dest_width/height */
0.0, 0.0, /* offset_[xy] */
SCALE_FACTOR, SCALE_FACTOR,
interp_type);
gdk_pixbuf_scale ((const GdkPixbuf *)source, copy,
0, dheight / 2, /* dest_[xy] */
dwidth / 2, dheight / 2, /* dest_width/height */
0.0, 0.0, /* offset_[xy] */
SCALE_FACTOR, SCALE_FACTOR,
interp_type);
gdk_pixbuf_scale ((const GdkPixbuf *)source, copy,
dwidth / 2, dheight / 2, /* dest_[xy] */
dwidth / 2, dheight / 2, /* dest_width/height */
0.0, 0.0, /* offset_[xy] */
SCALE_FACTOR, SCALE_FACTOR,
interp_type);
scaled = gdk_pixbuf_scale_simple (source, dwidth, dheight, interp_type);
g_assert_nonnull (scaled);
/* Compare the all-at-once and the composite images */
{
GError *error = NULL;
if (!pixdata_equal(scaled, copy, &error))
g_test_fail();
}
g_object_unref (G_OBJECT (source));
g_object_unref (G_OBJECT (copy));
g_object_unref (G_OBJECT (scaled));
}
int
main (int argc, char **argv)
{
GdkInterpType tiles = GDK_INTERP_TILES;
GdkInterpType bilinear = GDK_INTERP_BILINEAR;
GdkInterpType hyper = GDK_INTERP_HYPER;
g_test_init (&argc, &argv, NULL);
g_test_add_data_func ("/pixbuf/scale/two-step/tiles", &tiles, test_old_and_new);
g_test_add_data_func ("/pixbuf/scale/two-step/bilinear", &bilinear, test_old_and_new);
g_test_add_data_func ("/pixbuf/scale/two-step/hyper", &hyper, test_old_and_new);
g_test_add_data_func ("/pixbuf/scale/two-step/offset/tiles", &tiles, test_offset);
g_test_add_data_func ("/pixbuf/scale/two-step/offset/bilinear", &bilinear, test_offset);
g_test_add_data_func ("/pixbuf/scale/two-step/offset/hyper", &hyper, test_offset);
g_test_add_data_func ("/pixbuf/scale/two-step/dest/tiles", &tiles, test_dest);
g_test_add_data_func ("/pixbuf/scale/two-step/dest/bilinear", &bilinear, test_dest);
g_test_add_data_func ("/pixbuf/scale/two-step/dest/hyper", &hyper, test_dest);
return g_test_run ();
}