/* 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.
*/
/* Render a sorted vector path into an RGB buffer. */
#include "config.h"
#include "art_rgb_svp.h"
#include "art_svp.h"
#include "art_svp_render_aa.h"
#include "art_rgb.h"
typedef struct _ArtRgbSVPData ArtRgbSVPData;
typedef struct _ArtRgbSVPAlphaData ArtRgbSVPAlphaData;
struct _ArtRgbSVPData {
art_u32 rgbtab[256];
art_u8 *buf;
gint rowstride;
gint x0, x1;
};
struct _ArtRgbSVPAlphaData {
gint alphatab[256];
art_u8 r, g, b, alpha;
art_u8 *buf;
gint rowstride;
gint x0, x1;
};
static void
art_rgb_svp_callback (gpointer callback_data, gint y,
gint start, ArtSVPRenderAAStep *steps, gint n_steps)
{
ArtRgbSVPData *data = (ArtRgbSVPData *)callback_data;
art_u8 *linebuf;
gint run_x0, run_x1;
art_u32 running_sum = start;
art_u32 rgb;
gint x0, x1;
gint k;
linebuf = data->buf;
x0 = data->x0;
x1 = data->x1;
if (n_steps > 0)
{
run_x1 = steps[0].x;
if (run_x1 > x0)
{
rgb = data->rgbtab[(running_sum >> 16) & 0xff];
art_rgb_fill_run (linebuf,
rgb >> 16, (rgb >> 8) & 0xff, rgb & 0xff,
run_x1 - x0);
}
for (k = 0; k < n_steps - 1; k++)
{
running_sum += steps[k].delta;
run_x0 = run_x1;
run_x1 = steps[k + 1].x;
if (run_x1 > run_x0)
{
rgb = data->rgbtab[(running_sum >> 16) & 0xff];
art_rgb_fill_run (linebuf + (run_x0 - x0) * 3,
rgb >> 16, (rgb >> 8) & 0xff, rgb & 0xff,
run_x1 - run_x0);
}
}
running_sum += steps[k].delta;
if (x1 > run_x1)
{
rgb = data->rgbtab[(running_sum >> 16) & 0xff];
art_rgb_fill_run (linebuf + (run_x1 - x0) * 3,
rgb >> 16, (rgb >> 8) & 0xff, rgb & 0xff,
x1 - run_x1);
}
}
else
{
rgb = data->rgbtab[(running_sum >> 16) & 0xff];
art_rgb_fill_run (linebuf,
rgb >> 16, (rgb >> 8) & 0xff, rgb & 0xff,
x1 - x0);
}
data->buf += data->rowstride;
}
/* Render the vector path into the RGB buffer. */
/**
* art_rgb_svp_aa: Render sorted vector path into RGB buffer.
* @svp: The source sorted vector path.
* @x0: Left coordinate of destination rectangle.
* @y0: Top coordinate of destination rectangle.
* @x1: Right coordinate of destination rectangle.
* @y1: Bottom coordinate of destination rectangle.
* @fg_color: Foreground color in 0xRRGGBB format.
* @bg_color: Background color in 0xRRGGBB format.
* @buf: Destination RGB buffer.
* @rowstride: Rowstride of @buf buffer.
* @alphagamma: #ArtAlphaGamma for gamma-correcting the rendering.
*
* Renders the shape specified with @svp into the @buf RGB buffer.
* @x1 - @x0 specifies the width, and @y1 - @y0 specifies the height,
* of the rectangle rendered. The new pixels are stored starting at
* the first byte of @buf. Thus, the @x0 and @y0 parameters specify
* an offset within @svp, and may be tweaked as a way of doing
* integer-pixel translations without fiddling with @svp itself.
*
* The @fg_color and @bg_color arguments specify the opaque colors to
* be used for rendering. For pixels of entirely 0 winding-number,
* @bg_color is used. For pixels of entirely 1 winding number,
* @fg_color is used. In between, the color is interpolated based on
* the fraction of the pixel with a winding number of 1. If
* @alphagamma is NULL, then linear interpolation (in pixel counts) is
* the default. Otherwise, the interpolation is as specified by
* @alphagamma.
**/
void
art_rgb_svp_aa (const ArtSVP *svp,
gint x0, gint y0, gint x1, gint y1,
art_u32 fg_color, art_u32 bg_color,
art_u8 *buf, gint rowstride,
ArtAlphaGamma *alphagamma)
{
ArtRgbSVPData data;
gint r_fg, g_fg, b_fg;
gint r_bg, g_bg, b_bg;
gint r, g, b;
gint dr, dg, db;
gint i;
if (alphagamma == NULL)
{
r_fg = fg_color >> 16;
g_fg = (fg_color >> 8) & 0xff;
b_fg = fg_color & 0xff;
r_bg = bg_color >> 16;
g_bg = (bg_color >> 8) & 0xff;
b_bg = bg_color & 0xff;
r = (r_bg << 16) + 0x8000;
g = (g_bg << 16) + 0x8000;
b = (b_bg << 16) + 0x8000;
dr = ((r_fg - r_bg) << 16) / 255;
dg = ((g_fg - g_bg) << 16) / 255;
db = ((b_fg - b_bg) << 16) / 255;
for (i = 0; i < 256; i++)
{
data.rgbtab[i] = (r & 0xff0000) | ((g & 0xff0000) >> 8) | (b >> 16);
r += dr;
g += dg;
b += db;
}
}
else
{
gint *table;
art_u8 *invtab;
table = alphagamma->table;
r_fg = table[fg_color >> 16];
g_fg = table[(fg_color >> 8) & 0xff];
b_fg = table[fg_color & 0xff];
r_bg = table[bg_color >> 16];
g_bg = table[(bg_color >> 8) & 0xff];
b_bg = table[bg_color & 0xff];
r = (r_bg << 16) + 0x8000;
g = (g_bg << 16) + 0x8000;
b = (b_bg << 16) + 0x8000;
dr = ((r_fg - r_bg) << 16) / 255;
dg = ((g_fg - g_bg) << 16) / 255;
db = ((b_fg - b_bg) << 16) / 255;
invtab = alphagamma->invtable;
for (i = 0; i < 256; i++)
{
data.rgbtab[i] = (invtab[r >> 16] << 16) |
(invtab[g >> 16] << 8) |
invtab[b >> 16];
r += dr;
g += dg;
b += db;
}
}
data.buf = buf;
data.rowstride = rowstride;
data.x0 = x0;
data.x1 = x1;
art_svp_render_aa (svp, x0, y0, x1, y1, art_rgb_svp_callback, &data);
}
static void
art_rgb_svp_alpha_callback (gpointer callback_data, gint y,
gint start, ArtSVPRenderAAStep *steps, gint n_steps)
{
ArtRgbSVPAlphaData *data = (ArtRgbSVPAlphaData *)callback_data;
art_u8 *linebuf;
gint run_x0, run_x1;
art_u32 running_sum = start;
gint x0, x1;
gint k;
art_u8 r, g, b;
gint *alphatab;
gint alpha;
linebuf = data->buf;
x0 = data->x0;
x1 = data->x1;
r = data->r;
g = data->g;
b = data->b;
alphatab = data->alphatab;
if (n_steps > 0)
{
run_x1 = steps[0].x;
if (run_x1 > x0)
{
alpha = (running_sum >> 16) & 0xff;
if (alpha)
art_rgb_run_alpha (linebuf,
r, g, b, alphatab[alpha],
run_x1 - x0);
}
for (k = 0; k < n_steps - 1; k++)
{
running_sum += steps[k].delta;
run_x0 = run_x1;
run_x1 = steps[k + 1].x;
if (run_x1 > run_x0)
{
alpha = (running_sum >> 16) & 0xff;
if (alpha)
art_rgb_run_alpha (linebuf + (run_x0 - x0) * 3,
r, g, b, alphatab[alpha],
run_x1 - run_x0);
}
}
running_sum += steps[k].delta;
if (x1 > run_x1)
{
alpha = (running_sum >> 16) & 0xff;
if (alpha)
art_rgb_run_alpha (linebuf + (run_x1 - x0) * 3,
r, g, b, alphatab[alpha],
x1 - run_x1);
}
}
else
{
alpha = (running_sum >> 16) & 0xff;
if (alpha)
art_rgb_run_alpha (linebuf,
r, g, b, alphatab[alpha],
x1 - x0);
}
data->buf += data->rowstride;
}
static void
art_rgb_svp_alpha_opaque_callback (gpointer callback_data, gint y,
gint start,
ArtSVPRenderAAStep *steps, gint n_steps)
{
ArtRgbSVPAlphaData *data = (ArtRgbSVPAlphaData *)callback_data;
art_u8 *linebuf;
gint run_x0, run_x1;
art_u32 running_sum = start;
gint x0, x1;
gint k;
art_u8 r, g, b;
gint *alphatab;
gint alpha;
linebuf = data->buf;
x0 = data->x0;
x1 = data->x1;
r = data->r;
g = data->g;
b = data->b;
alphatab = data->alphatab;
if (n_steps > 0)
{
run_x1 = steps[0].x;
if (run_x1 > x0)
{
alpha = running_sum >> 16;
if (alpha)
{
if (alpha >= 255)
art_rgb_fill_run (linebuf,
r, g, b,
run_x1 - x0);
else
art_rgb_run_alpha (linebuf,
r, g, b, alphatab[alpha],
run_x1 - x0);
}
}
for (k = 0; k < n_steps - 1; k++)
{
running_sum += steps[k].delta;
run_x0 = run_x1;
run_x1 = steps[k + 1].x;
if (run_x1 > run_x0)
{
alpha = running_sum >> 16;
if (alpha)
{
if (alpha >= 255)
art_rgb_fill_run (linebuf + (run_x0 - x0) * 3,
r, g, b,
run_x1 - run_x0);
else
art_rgb_run_alpha (linebuf + (run_x0 - x0) * 3,
r, g, b, alphatab[alpha],
run_x1 - run_x0);
}
}
}
running_sum += steps[k].delta;
if (x1 > run_x1)
{
alpha = running_sum >> 16;
if (alpha)
{
if (alpha >= 255)
art_rgb_fill_run (linebuf + (run_x1 - x0) * 3,
r, g, b,
x1 - run_x1);
else
art_rgb_run_alpha (linebuf + (run_x1 - x0) * 3,
r, g, b, alphatab[alpha],
x1 - run_x1);
}
}
}
else
{
alpha = running_sum >> 16;
if (alpha)
{
if (alpha >= 255)
art_rgb_fill_run (linebuf,
r, g, b,
x1 - x0);
else
art_rgb_run_alpha (linebuf,
r, g, b, alphatab[alpha],
x1 - x0);
}
}
data->buf += data->rowstride;
}
/**
* art_rgb_svp_alpha: Alpha-composite sorted vector path over RGB buffer.
* @svp: The source sorted vector path.
* @x0: Left coordinate of destination rectangle.
* @y0: Top coordinate of destination rectangle.
* @x1: Right coordinate of destination rectangle.
* @y1: Bottom coordinate of destination rectangle.
* @rgba: Color in 0xRRGGBBAA format.
* @buf: Destination RGB buffer.
* @rowstride: Rowstride of @buf buffer.
* @alphagamma: #ArtAlphaGamma for gamma-correcting the compositing.
*
* Renders the shape specified with @svp over the @buf RGB buffer.
* @x1 - @x0 specifies the width, and @y1 - @y0 specifies the height,
* of the rectangle rendered. The new pixels are stored starting at
* the first byte of @buf. Thus, the @x0 and @y0 parameters specify
* an offset within @svp, and may be tweaked as a way of doing
* integer-pixel translations without fiddling with @svp itself.
*
* The @rgba argument specifies the color for the rendering. Pixels of
* entirely 0 winding number are left untouched. Pixels of entirely
* 1 winding number have the color @rgba composited over them (ie,
* are replaced by the red, green, blue components of @rgba if the alpha
* component is 0xff). Pixels of intermediate coverage are interpolated
* according to the rule in @alphagamma, or default to linear if
* @alphagamma is NULL.
**/
void
art_rgb_svp_alpha (const ArtSVP *svp,
gint x0, gint y0, gint x1, gint y1,
art_u32 rgba,
art_u8 *buf, gint rowstride,
ArtAlphaGamma *alphagamma)
{
ArtRgbSVPAlphaData data;
gint r, g, b, alpha;
gint i;
gint a, da;
r = rgba >> 24;
g = (rgba >> 16) & 0xff;
b = (rgba >> 8) & 0xff;
alpha = rgba & 0xff;
data.r = r;
data.g = g;
data.b = b;
data.alpha = alpha;
a = 0x8000;
da = (alpha * 66051 + 0x80) >> 8; /* 66051 equals 2 ^ 32 / (255 * 255) */
for (i = 0; i < 256; i++)
{
data.alphatab[i] = a >> 16;
a += da;
}
data.buf = buf;
data.rowstride = rowstride;
data.x0 = x0;
data.x1 = x1;
if (alpha == 255)
art_svp_render_aa (svp, x0, y0, x1, y1, art_rgb_svp_alpha_opaque_callback,
&data);
else
art_svp_render_aa (svp, x0, y0, x1, y1, art_rgb_svp_alpha_callback, &data);
}
