/* GdkPixbuf library - Utilities and miscellaneous convenience functions * * Copyright (C) 1999 The Free Software Foundation * * Authors: Federico Mena-Quintero * Cody Russell * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #include #include "gdk-pixbuf-private.h" #include /** * gdk_pixbuf_add_alpha: * @pixbuf: A #GdkPixbuf. * @substitute_color: Whether to set a color to zero opacity. If this * is %FALSE, then the (@r, @g, @b) arguments will be ignored. * @r: Red value to substitute. * @g: Green value to substitute. * @b: Blue value to substitute. * * Takes an existing pixbuf and adds an alpha channel to it. * If the existing pixbuf already had an alpha channel, the channel * values are copied from the original; otherwise, the alpha channel * is initialized to 255 (full opacity). * * If @substitute_color is %TRUE, then the color specified by (@r, @g, @b) will be * assigned zero opacity. That is, if you pass (255, 255, 255) for the * substitute color, all white pixels will become fully transparent. * * Return value: A newly-created pixbuf with a reference count of 1. **/ GdkPixbuf * gdk_pixbuf_add_alpha (const GdkPixbuf *pixbuf, gboolean substitute_color, guchar r, guchar g, guchar b) { GdkPixbuf *new_pixbuf; int x, y; g_return_val_if_fail (pixbuf != NULL, NULL); g_return_val_if_fail (pixbuf->colorspace == GDK_COLORSPACE_RGB, NULL); g_return_val_if_fail (pixbuf->n_channels == 3 || pixbuf->n_channels == 4, NULL); g_return_val_if_fail (pixbuf->bits_per_sample == 8, NULL); if (pixbuf->has_alpha) { new_pixbuf = gdk_pixbuf_copy (pixbuf); if (!new_pixbuf) return NULL; if (!substitute_color) return new_pixbuf; } else { new_pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8, pixbuf->width, pixbuf->height); } if (!new_pixbuf) return NULL; for (y = 0; y < pixbuf->height; y++) { guchar *src, *dest; guchar tr, tg, tb; src = pixbuf->pixels + y * pixbuf->rowstride; dest = new_pixbuf->pixels + y * new_pixbuf->rowstride; if (pixbuf->has_alpha) { /* Just subst color, we already copied everything else */ for (x = 0; x < pixbuf->width; x++) { if (src[0] == r && src[1] == g && src[2] == b) dest[3] = 0; src += 4; dest += 4; } } else { for (x = 0; x < pixbuf->width; x++) { tr = *dest++ = *src++; tg = *dest++ = *src++; tb = *dest++ = *src++; if (substitute_color && tr == r && tg == g && tb == b) *dest++ = 0; else *dest++ = 255; } } } return new_pixbuf; } /** * gdk_pixbuf_copy_area: * @src_pixbuf: Source pixbuf. * @src_x: Source X coordinate within @src_pixbuf. * @src_y: Source Y coordinate within @src_pixbuf. * @width: Width of the area to copy. * @height: Height of the area to copy. * @dest_pixbuf: Destination pixbuf. * @dest_x: X coordinate within @dest_pixbuf. * @dest_y: Y coordinate within @dest_pixbuf. * * Copies a rectangular area from @src_pixbuf to @dest_pixbuf. Conversion of * pixbuf formats is done automatically. **/ void gdk_pixbuf_copy_area (const GdkPixbuf *src_pixbuf, int src_x, int src_y, int width, int height, GdkPixbuf *dest_pixbuf, int dest_x, int dest_y) { g_return_if_fail (src_pixbuf != NULL); g_return_if_fail (dest_pixbuf != NULL); g_return_if_fail (src_x >= 0 && src_x + width <= src_pixbuf->width); g_return_if_fail (src_y >= 0 && src_y + height <= src_pixbuf->height); g_return_if_fail (dest_x >= 0 && dest_x + width <= dest_pixbuf->width); g_return_if_fail (dest_y >= 0 && dest_y + height <= dest_pixbuf->height); g_return_if_fail (!(gdk_pixbuf_get_has_alpha (src_pixbuf) && !gdk_pixbuf_get_has_alpha (dest_pixbuf))); /* This will perform format conversions automatically */ gdk_pixbuf_scale (src_pixbuf, dest_pixbuf, dest_x, dest_y, width, height, (double) (dest_x - src_x), (double) (dest_y - src_y), 1.0, 1.0, GDK_INTERP_NEAREST); } #define INTENSITY(r, g, b) ((r) * 0.30 + (g) * 0.59 + (b) * 0.11) /** * gdk_pixbuf_saturate_and_pixelate: * @src: source image * @dest: place to write modified version of @src * @saturation: saturation factor * @pixelate: whether to pixelate * * Modifies saturation and optionally pixelates @src, placing the * result in @dest. @src and @dest may be the same pixbuf with no ill * effects. If @saturation is 1.0 then saturation is not changed. If * it's less than 1.0, saturation is reduced (the image is darkened); * if greater than 1.0, saturation is increased (the image is * brightened). If @pixelate is %TRUE, then pixels are faded in a * checkerboard pattern to create a pixelated image. @src and @dest * must have the same image format, size, and rowstride. * **/ void gdk_pixbuf_saturate_and_pixelate(const GdkPixbuf *src, GdkPixbuf *dest, gfloat saturation, gboolean pixelate) { /* NOTE that src and dest MAY be the same pixbuf! */ g_return_if_fail (GDK_IS_PIXBUF (src)); g_return_if_fail (GDK_IS_PIXBUF (dest)); g_return_if_fail (gdk_pixbuf_get_height (src) == gdk_pixbuf_get_height (dest)); g_return_if_fail (gdk_pixbuf_get_width (src) == gdk_pixbuf_get_width (dest)); g_return_if_fail (gdk_pixbuf_get_rowstride (src) == gdk_pixbuf_get_rowstride (dest)); g_return_if_fail (gdk_pixbuf_get_colorspace (src) == gdk_pixbuf_get_colorspace (dest)); if (saturation == 1.0 && !pixelate) { if (dest != src) memcpy (gdk_pixbuf_get_pixels (dest), gdk_pixbuf_get_pixels (src), gdk_pixbuf_get_height (src) * gdk_pixbuf_get_rowstride (src)); return; } else { gint i, j; gint width, height, has_alpha, rowstride; guchar *target_pixels; guchar *original_pixels; guchar *current_pixel; guchar intensity; has_alpha = gdk_pixbuf_get_has_alpha (src); width = gdk_pixbuf_get_width (src); height = gdk_pixbuf_get_height (src); rowstride = gdk_pixbuf_get_rowstride (src); target_pixels = gdk_pixbuf_get_pixels (dest); original_pixels = gdk_pixbuf_get_pixels (src); for (i = 0; i < height; i++) { for (j = 0; j < width; j++) { current_pixel = original_pixels + i*rowstride + j*(has_alpha?4:3); intensity = INTENSITY (*(current_pixel), *(current_pixel + 1), *(current_pixel + 2)); if (pixelate && (i+j)%2 == 0) { *(target_pixels + i*rowstride + j*(has_alpha?4:3)) = intensity/2 + 127; *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 1) = intensity/2 + 127; *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 2) = intensity/2 + 127; } else if (pixelate) { #define DARK_FACTOR 0.7 *(target_pixels + i*rowstride + j*(has_alpha?4:3)) = (guchar) (((1.0 - saturation) * intensity + saturation * (*(current_pixel)))) * DARK_FACTOR; *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 1) = (guchar) (((1.0 - saturation) * intensity + saturation * (*(current_pixel + 1)))) * DARK_FACTOR; *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 2) = (guchar) (((1.0 - saturation) * intensity + saturation * (*(current_pixel + 2)))) * DARK_FACTOR; } else { *(target_pixels + i*rowstride + j*(has_alpha?4:3)) = (guchar) ((1.0 - saturation) * intensity + saturation * (*(current_pixel))); *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 1) = (guchar) ((1.0 - saturation) * intensity + saturation * (*(current_pixel + 1))); *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 2) = (guchar) ((1.0 - saturation) * intensity + saturation * (*(current_pixel + 2))); } if (has_alpha) *(target_pixels + i*rowstride + j*(has_alpha?4:3) + 3) = *(current_pixel + 3); } } return; } }