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/*
* Copyright © 2004 Keith Packard
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that
* copyright notice and this permission notice appear in supporting
* documentation, and that the name of Keith Packard not be used in
* advertising or publicity pertaining to distribution of the software without
* specific, written prior permission. Keith Packard makes no
* representations about the suitability of this software for any purpose. It
* is provided "as is" without express or implied warranty.
*
* KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <string.h>
#include "pixman-private.h"
#include "pixman-accessor.h"
/*
* Step across a small sample grid gap
*/
#define RENDER_EDGE_STEP_SMALL(edge) \
{ \
edge->x += edge->stepx_small; \
edge->e += edge->dx_small; \
if (edge->e > 0) \
{ \
edge->e -= edge->dy; \
edge->x += edge->signdx; \
} \
}
/*
* Step across a large sample grid gap
*/
#define RENDER_EDGE_STEP_BIG(edge) \
{ \
edge->x += edge->stepx_big; \
edge->e += edge->dx_big; \
if (edge->e > 0) \
{ \
edge->e -= edge->dy; \
edge->x += edge->signdx; \
} \
}
#ifdef PIXMAN_FB_ACCESSORS
#define PIXMAN_RASTERIZE_EDGES pixman_rasterize_edges_accessors
#else
#define PIXMAN_RASTERIZE_EDGES pixman_rasterize_edges_no_accessors
#endif
/*
* 4 bit alpha
*/
#define N_BITS 4
#define RASTERIZE_EDGES rasterize_edges_4
#ifndef WORDS_BIGENDIAN
#define SHIFT_4(o) ((o) << 2)
#else
#define SHIFT_4(o) ((1 - (o)) << 2)
#endif
#define GET_4(x, o) (((x) >> SHIFT_4 (o)) & 0xf)
#define PUT_4(x, o, v) \
(((x) & ~(0xf << SHIFT_4 (o))) | (((v) & 0xf) << SHIFT_4 (o)))
#define DEFINE_ALPHA(line, x) \
uint8_t *__ap = (uint8_t *) line + ((x) >> 1); \
int __ao = (x) & 1
#define STEP_ALPHA ((__ap += __ao), (__ao ^= 1))
#define ADD_ALPHA(a) \
{ \
uint8_t __o = READ (image, __ap); \
uint8_t __a = (a) + GET_4 (__o, __ao); \
WRITE (image, __ap, PUT_4 (__o, __ao, __a | (0 - ((__a) >> 4)))); \
}
#include "pixman-edge-imp.h"
#undef ADD_ALPHA
#undef STEP_ALPHA
#undef DEFINE_ALPHA
#undef RASTERIZE_EDGES
#undef N_BITS
/*
* 1 bit alpha
*/
#define N_BITS 1
#define RASTERIZE_EDGES rasterize_edges_1
#include "pixman-edge-imp.h"
#undef RASTERIZE_EDGES
#undef N_BITS
/*
* 8 bit alpha
*/
static force_inline uint8_t
clip255 (int x)
{
if (x > 255)
return 255;
return x;
}
#define ADD_SATURATE_8(buf, val, length) \
do \
{ \
int i__ = (length); \
uint8_t *buf__ = (buf); \
int val__ = (val); \
\
while (i__--) \
{ \
WRITE (image, (buf__), clip255 (READ (image, (buf__)) + (val__))); \
(buf__)++; \
} \
} while (0)
/*
* We want to detect the case where we add the same value to a long
* span of pixels. The triangles on the end are filled in while we
* count how many sub-pixel scanlines contribute to the middle section.
*
* +--------------------------+
* fill_height =| \ /
* +------------------+
* |================|
* fill_start fill_end
*/
static void
rasterize_edges_8 (pixman_image_t *image,
pixman_edge_t * l,
pixman_edge_t * r,
pixman_fixed_t t,
pixman_fixed_t b)
{
pixman_fixed_t y = t;
uint32_t *line;
int fill_start = -1, fill_end = -1;
int fill_size = 0;
uint32_t *buf = (image)->bits.bits;
int stride = (image)->bits.rowstride;
int width = (image)->bits.width;
line = buf + pixman_fixed_to_int (y) * stride;
for (;;)
{
uint8_t *ap = (uint8_t *) line;
pixman_fixed_t lx, rx;
int lxi, rxi;
/* clip X */
lx = l->x;
if (lx < 0)
lx = 0;
rx = r->x;
if (pixman_fixed_to_int (rx) >= width)
{
/* Use the last pixel of the scanline, covered 100%.
* We can't use the first pixel following the scanline,
* because accessing it could result in a buffer overrun.
*/
rx = pixman_int_to_fixed (width) - 1;
}
/* Skip empty (or backwards) sections */
if (rx > lx)
{
int lxs, rxs;
/* Find pixel bounds for span. */
lxi = pixman_fixed_to_int (lx);
rxi = pixman_fixed_to_int (rx);
/* Sample coverage for edge pixels */
lxs = RENDER_SAMPLES_X (lx, 8);
rxs = RENDER_SAMPLES_X (rx, 8);
/* Add coverage across row */
if (lxi == rxi)
{
WRITE (image, ap + lxi,
clip255 (READ (image, ap + lxi) + rxs - lxs));
}
else
{
WRITE (image, ap + lxi,
clip255 (READ (image, ap + lxi) + N_X_FRAC (8) - lxs));
/* Move forward so that lxi/rxi is the pixel span */
lxi++;
/* Don't bother trying to optimize the fill unless
* the span is longer than 4 pixels. */
if (rxi - lxi > 4)
{
if (fill_start < 0)
{
fill_start = lxi;
fill_end = rxi;
fill_size++;
}
else
{
if (lxi >= fill_end || rxi < fill_start)
{
/* We're beyond what we saved, just fill it */
ADD_SATURATE_8 (ap + fill_start,
fill_size * N_X_FRAC (8),
fill_end - fill_start);
fill_start = lxi;
fill_end = rxi;
fill_size = 1;
}
else
{
/* Update fill_start */
if (lxi > fill_start)
{
ADD_SATURATE_8 (ap + fill_start,
fill_size * N_X_FRAC (8),
lxi - fill_start);
fill_start = lxi;
}
else if (lxi < fill_start)
{
ADD_SATURATE_8 (ap + lxi, N_X_FRAC (8),
fill_start - lxi);
}
/* Update fill_end */
if (rxi < fill_end)
{
ADD_SATURATE_8 (ap + rxi,
fill_size * N_X_FRAC (8),
fill_end - rxi);
fill_end = rxi;
}
else if (fill_end < rxi)
{
ADD_SATURATE_8 (ap + fill_end,
N_X_FRAC (8),
rxi - fill_end);
}
fill_size++;
}
}
}
else
{
ADD_SATURATE_8 (ap + lxi, N_X_FRAC (8), rxi - lxi);
}
WRITE (image, ap + rxi, clip255 (READ (image, ap + rxi) + rxs));
}
}
if (y == b)
{
/* We're done, make sure we clean up any remaining fill. */
if (fill_start != fill_end)
{
if (fill_size == N_Y_FRAC (8))
{
MEMSET_WRAPPED (image, ap + fill_start,
0xff, fill_end - fill_start);
}
else
{
ADD_SATURATE_8 (ap + fill_start, fill_size * N_X_FRAC (8),
fill_end - fill_start);
}
}
break;
}
if (pixman_fixed_frac (y) != Y_FRAC_LAST (8))
{
RENDER_EDGE_STEP_SMALL (l);
RENDER_EDGE_STEP_SMALL (r);
y += STEP_Y_SMALL (8);
}
else
{
RENDER_EDGE_STEP_BIG (l);
RENDER_EDGE_STEP_BIG (r);
y += STEP_Y_BIG (8);
if (fill_start != fill_end)
{
if (fill_size == N_Y_FRAC (8))
{
MEMSET_WRAPPED (image, ap + fill_start,
0xff, fill_end - fill_start);
}
else
{
ADD_SATURATE_8 (ap + fill_start, fill_size * N_X_FRAC (8),
fill_end - fill_start);
}
fill_start = fill_end = -1;
fill_size = 0;
}
line += stride;
}
}
}
#ifndef PIXMAN_FB_ACCESSORS
static
#endif
void
PIXMAN_RASTERIZE_EDGES (pixman_image_t *image,
pixman_edge_t * l,
pixman_edge_t * r,
pixman_fixed_t t,
pixman_fixed_t b)
{
switch (PIXMAN_FORMAT_BPP (image->bits.format))
{
case 1:
rasterize_edges_1 (image, l, r, t, b);
break;
case 4:
rasterize_edges_4 (image, l, r, t, b);
break;
case 8:
rasterize_edges_8 (image, l, r, t, b);
break;
default:
break;
}
}
#ifndef PIXMAN_FB_ACCESSORS
PIXMAN_EXPORT void
pixman_rasterize_edges (pixman_image_t *image,
pixman_edge_t * l,
pixman_edge_t * r,
pixman_fixed_t t,
pixman_fixed_t b)
{
return_if_fail (image->type == BITS);
return_if_fail (PIXMAN_FORMAT_TYPE (image->bits.format) == PIXMAN_TYPE_A);
if (image->bits.read_func || image->bits.write_func)
pixman_rasterize_edges_accessors (image, l, r, t, b);
else
pixman_rasterize_edges_no_accessors (image, l, r, t, b);
}
#endif