/* 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 "config.h"
#include "art_rgb_bitmap_affine.h"
#include <math.h>
#include "art_misc.h"
#include "art_point.h"
#include "art_affine.h"
#include "art_rgb_affine_private.h"
/* This module handles compositing of affine-transformed bitmap images
over rgb pixel buffers. */
/* Composite the source image over the destination image, applying the
affine transform. Foreground color is given and assumed to be
opaque, background color is assumed to be fully transparent. */
static void
art_rgb_bitmap_affine_opaque (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;
art_u8 r, g, b;
int run_x0, run_x1;
r = rgb >> 16;
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 >> 3);
if (*src_p & (128 >> (src_x & 7)))
{
dst_p[0] = r;
dst_p[1] = g;
dst_p[2] = b;
}
dst_p += 3;
}
dst_linestart += dst_rowstride;
}
}
/* Composite the source image over the destination image, applying the
affine transform. Foreground color is given, background color is
assumed to be fully transparent. */
/**
* art_rgb_bitmap_affine: Affine transform source bitmap 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 bitmap buffer.
* @src_width: Width of source image.
* @src_height: Height of source image.
* @src_rowstride: Rowstride of @src buffer.
* @rgba: RGBA foreground color, in 0xRRGGBBAA.
* @affine: Affine transform.
* @level: Filter level.
* @alphagamma: #ArtAlphaGamma for gamma-correcting the compositing.
*
* Affine transform the source image stored in @src, compositing over
* the area of destination image @dst specified by the rectangle
* (@x0, @y0) - (@x1, @y1).
*
* The source bitmap stored with MSB as the leftmost pixel. Source 1
* bits correspond to the semitransparent color @rgba, while source 0
* bits are transparent.
*
* See art_rgb_affine() for a description of additional parameters.
**/
void
art_rgb_bitmap_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 rgba,
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;
art_u8 r, g, b;
int run_x0, run_x1;
alpha = rgba & 0xff;
if (alpha == 0xff)
{
art_rgb_bitmap_affine_opaque (dst, x0, y0, x1, y1, dst_rowstride,
src,
src_width, src_height, src_rowstride,
rgba >> 8,
affine,
level,
alphagamma);
return;
}
/* alpha = (65536 * alpha) / 255; */
alpha = (alpha << 8) + alpha + (alpha >> 7);
r = rgba >> 24;
g = (rgba >> 16) & 0xff;
b = (rgba >> 8) & 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 >> 3);
if (*src_p & (128 >> (src_x & 7)))
{
bg_r = dst_p[0];
bg_g = dst_p[1];
bg_b = dst_p[2];
fg_r = bg_r + (((r - bg_r) * alpha + 0x8000) >> 16);
fg_g = bg_g + (((g - bg_g) * alpha + 0x8000) >> 16);
fg_b = bg_b + (((b - bg_b) * alpha + 0x8000) >> 16);
dst_p[0] = fg_r;
dst_p[1] = fg_g;
dst_p[2] = fg_b;
}
dst_p += 3;
}
dst_linestart += dst_rowstride;
}
}
