+++ /dev/null
-/* Libart_LGPL - library of basic graphic primitives
- * Copyright (C) 1998 Raph Levien
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library 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
- * Library General Public License for more details.
- *
- * You should have received a copy of the GNU Library 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 <math.h>
-#include "art_misc.h"
-#include "art_point.h"
-#include "art_affine.h"
-#include "art_rgb_affine_private.h"
-#include "art_rgb_a_affine.h"
-
-/* This module handles compositing of affine-transformed alpha only images
- over rgb pixel buffers. */
-
-/* Composite the source image over the destination image, applying the
- affine transform. */
-
-/**
- * art_rgb_a_affine: Affine transform source Alpha image and composite.
- * @dst: Destination image RGB buffer.
- * @x0: Left coordinate of destination rectangle.
- * @y0: Top coordinate of destination rectangle.
- * @x1: Right coordinate of destination rectangle.
- * @y1: Bottom coordinate of destination rectangle.
- * @dst_rowstride: Rowstride of @dst buffer.
- * @src: Source image alpha buffer.
- * @src_width: Width of source image.
- * @src_height: Height of source image.
- * @src_rowstride: Rowstride of @src buffer.
- * @rgb: RGB foreground color, in 0xRRGGBB.
- * @affine: Affine transform.
- * @level: Filter level.
- * @alphagamma: #ArtAlphaGamma for gamma-correcting the compositing.
- *
- * Affine transform the solid color rgb with alpha specified by the
- * source image stored in @src, compositing over the area of destination
- * image @dst specified by the rectangle (@x0, @y0) - (@x1, @y1).
- * As usual in libart, the left and top edges of this rectangle are
- * included, and the right and bottom edges are excluded.
- *
- * The @alphagamma parameter specifies that the alpha compositing be
- * done in a gamma-corrected color space. In the current
- * implementation, it is ignored.
- *
- * The @level parameter specifies the speed/quality tradeoff of the
- * image interpolation. Currently, only ART_FILTER_NEAREST is
- * implemented.
- **/
-void
-art_rgb_a_affine (art_u8 *dst,
- int x0, int y0, int x1, int y1, int dst_rowstride,
- const art_u8 *src,
- int src_width, int src_height, int src_rowstride,
- art_u32 rgb,
- const double affine[6],
- ArtFilterLevel level,
- ArtAlphaGamma *alphagamma)
-{
- /* Note: this is a slow implementation, and is missing all filter
- levels other than NEAREST. It is here for clarity of presentation
- and to establish the interface. */
- int x, y;
- double inv[6];
- art_u8 *dst_p, *dst_linestart;
- const art_u8 *src_p;
- ArtPoint pt, src_pt;
- int src_x, src_y;
- int alpha;
- art_u8 bg_r, bg_g, bg_b;
- art_u8 fg_r, fg_g, fg_b;
- int tmp;
- int run_x0, run_x1;
- art_u8 r, g, b;
-
- r = (rgb>>16)&0xff;
- g = (rgb>>8)&0xff;
- b = (rgb)&0xff;
-
- dst_linestart = dst;
- art_affine_invert (inv, affine);
- for (y = y0; y < y1; y++)
- {
- pt.y = y + 0.5;
- run_x0 = x0;
- run_x1 = x1;
- art_rgb_affine_run (&run_x0, &run_x1, y, src_width, src_height,
- inv);
- dst_p = dst_linestart + (run_x0 - x0) * 3;
- for (x = run_x0; x < run_x1; x++)
- {
- pt.x = x + 0.5;
- art_affine_point (&src_pt, &pt, inv);
- src_x = floor (src_pt.x);
- src_y = floor (src_pt.y);
- src_p = src + (src_y * src_rowstride) + src_x;
- if (src_x >= 0 && src_x < src_width &&
- src_y >= 0 && src_y < src_height)
- {
-
- alpha = *src_p;
- if (alpha)
- {
- if (alpha == 255)
- {
- dst_p[0] = r;
- dst_p[1] = g;
- dst_p[2] = b;
- }
- else
- {
- bg_r = dst_p[0];
- bg_g = dst_p[1];
- bg_b = dst_p[2];
-
- tmp = (r - bg_r) * alpha;
- fg_r = bg_r + ((tmp + (tmp >> 8) + 0x80) >> 8);
- tmp = (g - bg_g) * alpha;
- fg_g = bg_g + ((tmp + (tmp >> 8) + 0x80) >> 8);
- tmp = (b - bg_b) * alpha;
- fg_b = bg_b + ((tmp + (tmp >> 8) + 0x80) >> 8);
-
- dst_p[0] = fg_r;
- dst_p[1] = fg_g;
- dst_p[2] = fg_b;
- }
- }
- } else { dst_p[0] = 255; dst_p[1] = 0; dst_p[2] = 0; }
- dst_p += 3;
- }
- dst_linestart += dst_rowstride;
- }
-}
projects / rrdtool.git / blobdiff