/*
* Copyright © 2002 Keith Packard, member of The XFree86 Project, Inc.
* 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 <stdio.h>
#include <stdlib.h>
#include "pixman-private.h"
/*
* Compute the smallest value greater than or equal to y which is on a
* grid row.
*/
PIXMAN_EXPORT pixman_fixed_t
pixman_sample_ceil_y (pixman_fixed_t y, int n)
{
pixman_fixed_t f = pixman_fixed_frac (y);
pixman_fixed_t i = pixman_fixed_floor (y);
f = DIV (f - Y_FRAC_FIRST (n) + (STEP_Y_SMALL (n) - pixman_fixed_e), STEP_Y_SMALL (n)) * STEP_Y_SMALL (n) +
Y_FRAC_FIRST (n);
if (f > Y_FRAC_LAST (n))
{
if (pixman_fixed_to_int (i) == 0x7fff)
{
f = 0xffff; /* saturate */
}
else
{
f = Y_FRAC_FIRST (n);
i += pixman_fixed_1;
}
}
return (i | f);
}
/*
* Compute the largest value strictly less than y which is on a
* grid row.
*/
PIXMAN_EXPORT pixman_fixed_t
pixman_sample_floor_y (pixman_fixed_t y,
int n)
{
pixman_fixed_t f = pixman_fixed_frac (y);
pixman_fixed_t i = pixman_fixed_floor (y);
f = DIV (f - pixman_fixed_e - Y_FRAC_FIRST (n), STEP_Y_SMALL (n)) * STEP_Y_SMALL (n) +
Y_FRAC_FIRST (n);
if (f < Y_FRAC_FIRST (n))
{
if (pixman_fixed_to_int (i) == 0x8000)
{
f = 0; /* saturate */
}
else
{
f = Y_FRAC_LAST (n);
i -= pixman_fixed_1;
}
}
return (i | f);
}
/*
* Step an edge by any amount (including negative values)
*/
PIXMAN_EXPORT void
pixman_edge_step (pixman_edge_t *e,
int n)
{
pixman_fixed_48_16_t ne;
e->x += n * e->stepx;
ne = e->e + n * (pixman_fixed_48_16_t) e->dx;
if (n >= 0)
{
if (ne > 0)
{
int nx = (ne + e->dy - 1) / e->dy;
e->e = ne - nx * (pixman_fixed_48_16_t) e->dy;
e->x += nx * e->signdx;
}
}
else
{
if (ne <= -e->dy)
{
int nx = (-ne) / e->dy;
e->e = ne + nx * (pixman_fixed_48_16_t) e->dy;
e->x -= nx * e->signdx;
}
}
}
/*
* A private routine to initialize the multi-step
* elements of an edge structure
*/
static void
_pixman_edge_multi_init (pixman_edge_t * e,
int n,
pixman_fixed_t *stepx_p,
pixman_fixed_t *dx_p)
{
pixman_fixed_t stepx;
pixman_fixed_48_16_t ne;
ne = n * (pixman_fixed_48_16_t) e->dx;
stepx = n * e->stepx;
if (ne > 0)
{
int nx = ne / e->dy;
ne -= nx * (pixman_fixed_48_16_t)e->dy;
stepx += nx * e->signdx;
}
*dx_p = ne;
*stepx_p = stepx;
}
/*
* Initialize one edge structure given the line endpoints and a
* starting y value
*/
PIXMAN_EXPORT void
pixman_edge_init (pixman_edge_t *e,
int n,
pixman_fixed_t y_start,
pixman_fixed_t x_top,
pixman_fixed_t y_top,
pixman_fixed_t x_bot,
pixman_fixed_t y_bot)
{
pixman_fixed_t dx, dy;
e->x = x_top;
e->e = 0;
dx = x_bot - x_top;
dy = y_bot - y_top;
e->dy = dy;
e->dx = 0;
if (dy)
{
if (dx >= 0)
{
e->signdx = 1;
e->stepx = dx / dy;
e->dx = dx % dy;
e->e = -dy;
}
else
{
e->signdx = -1;
e->stepx = -(-dx / dy);
e->dx = -dx % dy;
e->e = 0;
}
_pixman_edge_multi_init (e, STEP_Y_SMALL (n),
&e->stepx_small, &e->dx_small);
_pixman_edge_multi_init (e, STEP_Y_BIG (n),
&e->stepx_big, &e->dx_big);
}
pixman_edge_step (e, y_start - y_top);
}
/*
* Initialize one edge structure given a line, starting y value
* and a pixel offset for the line
*/
PIXMAN_EXPORT void
pixman_line_fixed_edge_init (pixman_edge_t * e,
int n,
pixman_fixed_t y,
const pixman_line_fixed_t *line,
int x_off,
int y_off)
{
pixman_fixed_t x_off_fixed = pixman_int_to_fixed (x_off);
pixman_fixed_t y_off_fixed = pixman_int_to_fixed (y_off);
const pixman_point_fixed_t *top, *bot;
if (line->p1.y <= line->p2.y)
{
top = &line->p1;
bot = &line->p2;
}
else
{
top = &line->p2;
bot = &line->p1;
}
pixman_edge_init (e, n, y,
top->x + x_off_fixed,
top->y + y_off_fixed,
bot->x + x_off_fixed,
bot->y + y_off_fixed);
}
PIXMAN_EXPORT void
pixman_add_traps (pixman_image_t * image,
int16_t x_off,
int16_t y_off,
int ntrap,
const pixman_trap_t *traps)
{
int bpp;
int height;
pixman_fixed_t x_off_fixed;
pixman_fixed_t y_off_fixed;
pixman_edge_t l, r;
pixman_fixed_t t, b;
_pixman_image_validate (image);
height = image->bits.height;
bpp = PIXMAN_FORMAT_BPP (image->bits.format);
x_off_fixed = pixman_int_to_fixed (x_off);
y_off_fixed = pixman_int_to_fixed (y_off);
while (ntrap--)
{
t = traps->top.y + y_off_fixed;
if (t < 0)
t = 0;
t = pixman_sample_ceil_y (t, bpp);
b = traps->bot.y + y_off_fixed;
if (pixman_fixed_to_int (b) >= height)
b = pixman_int_to_fixed (height) - 1;
b = pixman_sample_floor_y (b, bpp);
if (b >= t)
{
/* initialize edge walkers */
pixman_edge_init (&l, bpp, t,
traps->top.l + x_off_fixed,
traps->top.y + y_off_fixed,
traps->bot.l + x_off_fixed,
traps->bot.y + y_off_fixed);
pixman_edge_init (&r, bpp, t,
traps->top.r + x_off_fixed,
traps->top.y + y_off_fixed,
traps->bot.r + x_off_fixed,
traps->bot.y + y_off_fixed);
pixman_rasterize_edges (image, &l, &r, t, b);
}
traps++;
}
}
#if 0
static void
dump_image (pixman_image_t *image,
const char * title)
{
int i, j;
if (!image->type == BITS)
printf ("%s is not a regular image\n", title);
if (!image->bits.format == PIXMAN_a8)
printf ("%s is not an alpha mask\n", title);
printf ("\n\n\n%s: \n", title);
for (i = 0; i < image->bits.height; ++i)
{
uint8_t *line =
(uint8_t *)&(image->bits.bits[i * image->bits.rowstride]);
for (j = 0; j < image->bits.width; ++j)
printf ("%c", line[j] ? '#' : ' ');
printf ("\n");
}
}
#endif
PIXMAN_EXPORT void
pixman_add_trapezoids (pixman_image_t * image,
int16_t x_off,
int y_off,
int ntraps,
const pixman_trapezoid_t *traps)
{
int i;
#if 0
dump_image (image, "before");
#endif
for (i = 0; i < ntraps; ++i)
{
const pixman_trapezoid_t *trap = &(traps[i]);
if (!pixman_trapezoid_valid (trap))
continue;
pixman_rasterize_trapezoid (image, trap, x_off, y_off);
}
#if 0
dump_image (image, "after");
#endif
}
PIXMAN_EXPORT void
pixman_rasterize_trapezoid (pixman_image_t * image,
const pixman_trapezoid_t *trap,
int x_off,
int y_off)
{
int bpp;
int height;
pixman_fixed_t y_off_fixed;
pixman_edge_t l, r;
pixman_fixed_t t, b;
return_if_fail (image->type == BITS);
_pixman_image_validate (image);
if (!pixman_trapezoid_valid (trap))
return;
height = image->bits.height;
bpp = PIXMAN_FORMAT_BPP (image->bits.format);
y_off_fixed = pixman_int_to_fixed (y_off);
t = trap->top + y_off_fixed;
if (t < 0)
t = 0;
t = pixman_sample_ceil_y (t, bpp);
b = trap->bottom + y_off_fixed;
if (pixman_fixed_to_int (b) >= height)
b = pixman_int_to_fixed (height) - 1;
b = pixman_sample_floor_y (b, bpp);
if (b >= t)
{
/* initialize edge walkers */
pixman_line_fixed_edge_init (&l, bpp, t, &trap->left, x_off, y_off);
pixman_line_fixed_edge_init (&r, bpp, t, &trap->right, x_off, y_off);
pixman_rasterize_edges (image, &l, &r, t, b);
}
}
static const pixman_bool_t zero_src_has_no_effect[PIXMAN_N_OPERATORS] =
{
FALSE, /* Clear 0 0 */
FALSE, /* Src 1 0 */
TRUE, /* Dst 0 1 */
TRUE, /* Over 1 1-Aa */
TRUE, /* OverReverse 1-Ab 1 */
FALSE, /* In Ab 0 */
FALSE, /* InReverse 0 Aa */
FALSE, /* Out 1-Ab 0 */
TRUE, /* OutReverse 0 1-Aa */
TRUE, /* Atop Ab 1-Aa */
FALSE, /* AtopReverse 1-Ab Aa */
TRUE, /* Xor 1-Ab 1-Aa */
TRUE, /* Add 1 1 */
};
static pixman_bool_t
get_trap_extents (pixman_op_t op, pixman_image_t *dest,
const pixman_trapezoid_t *traps, int n_traps,
pixman_box32_t *box)
{
int i;
/* When the operator is such that a zero source has an
* effect on the underlying image, we have to
* composite across the entire destination
*/
if (!zero_src_has_no_effect [op])
{
box->x1 = 0;
box->y1 = 0;
box->x2 = dest->bits.width;
box->y2 = dest->bits.height;
return TRUE;
}
box->x1 = INT32_MAX;
box->y1 = INT32_MAX;
box->x2 = INT32_MIN;
box->y2 = INT32_MIN;
for (i = 0; i < n_traps; ++i)
{
const pixman_trapezoid_t *trap = &(traps[i]);
int y1, y2;
if (!pixman_trapezoid_valid (trap))
continue;
y1 = pixman_fixed_to_int (trap->top);
if (y1 < box->y1)
box->y1 = y1;
y2 = pixman_fixed_to_int (pixman_fixed_ceil (trap->bottom));
if (y2 > box->y2)
box->y2 = y2;
#define EXTEND_MIN(x) \
if (pixman_fixed_to_int ((x)) < box->x1) \
box->x1 = pixman_fixed_to_int ((x));
#define EXTEND_MAX(x) \
if (pixman_fixed_to_int (pixman_fixed_ceil ((x))) > box->x2) \
box->x2 = pixman_fixed_to_int (pixman_fixed_ceil ((x)));
#define EXTEND(x) \
EXTEND_MIN(x); \
EXTEND_MAX(x);
EXTEND(trap->left.p1.x);
EXTEND(trap->left.p2.x);
EXTEND(trap->right.p1.x);
EXTEND(trap->right.p2.x);
}
if (box->x1 >= box->x2 || box->y1 >= box->y2)
return FALSE;
return TRUE;
}
/*
* pixman_composite_trapezoids()
*
* All the trapezoids are conceptually rendered to an infinitely big image.
* The (0, 0) coordinates of this image are then aligned with the (x, y)
* coordinates of the source image, and then both images are aligned with
* the (x, y) coordinates of the destination. Then these three images are
* composited across the entire destination.
*/
PIXMAN_EXPORT void
pixman_composite_trapezoids (pixman_op_t op,
pixman_image_t * src,
pixman_image_t * dst,
pixman_format_code_t mask_format,
int x_src,
int y_src,
int x_dst,
int y_dst,
int n_traps,
const pixman_trapezoid_t * traps)
{
int i;
return_if_fail (PIXMAN_FORMAT_TYPE (mask_format) == PIXMAN_TYPE_A);
if (n_traps <= 0)
return;
_pixman_image_validate (src);
_pixman_image_validate (dst);
if (op == PIXMAN_OP_ADD &&
(src->common.flags & FAST_PATH_IS_OPAQUE) &&
(mask_format == dst->common.extended_format_code) &&
!(dst->common.have_clip_region))
{
for (i = 0; i < n_traps; ++i)
{
const pixman_trapezoid_t *trap = &(traps[i]);
if (!pixman_trapezoid_valid (trap))
continue;
pixman_rasterize_trapezoid (dst, trap, x_dst, y_dst);
}
}
else
{
pixman_image_t *tmp;
pixman_box32_t box;
int i;
if (!get_trap_extents (op, dst, traps, n_traps, &box))
return;
if (!(tmp = pixman_image_create_bits (
mask_format, box.x2 - box.x1, box.y2 - box.y1, NULL, -1)))
return;
for (i = 0; i < n_traps; ++i)
{
const pixman_trapezoid_t *trap = &(traps[i]);
if (!pixman_trapezoid_valid (trap))
continue;
pixman_rasterize_trapezoid (tmp, trap, - box.x1, - box.y1);
}
pixman_image_composite (op, src, tmp, dst,
x_src + box.x1, y_src + box.y1,
0, 0,
x_dst + box.x1, y_dst + box.y1,
box.x2 - box.x1, box.y2 - box.y1);
pixman_image_unref (tmp);
}
}
static int
greater_y (const pixman_point_fixed_t *a, const pixman_point_fixed_t *b)
{
if (a->y == b->y)
return a->x > b->x;
return a->y > b->y;
}
/*
* Note that the definition of this function is a bit odd because
* of the X coordinate space (y increasing downwards).
*/
static int
clockwise (const pixman_point_fixed_t *ref,
const pixman_point_fixed_t *a,
const pixman_point_fixed_t *b)
{
pixman_point_fixed_t ad, bd;
ad.x = a->x - ref->x;
ad.y = a->y - ref->y;
bd.x = b->x - ref->x;
bd.y = b->y - ref->y;
return ((pixman_fixed_32_32_t) bd.y * ad.x -
(pixman_fixed_32_32_t) ad.y * bd.x) < 0;
}
static void
triangle_to_trapezoids (const pixman_triangle_t *tri, pixman_trapezoid_t *traps)
{
const pixman_point_fixed_t *top, *left, *right, *tmp;
top = &tri->p1;
left = &tri->p2;
right = &tri->p3;
if (greater_y (top, left))
{
tmp = left;
left = top;
top = tmp;
}
if (greater_y (top, right))
{
tmp = right;
right = top;
top = tmp;
}
if (clockwise (top, right, left))
{
tmp = right;
right = left;
left = tmp;
}
/*
* Two cases:
*
* + +
* / \ / \
* / \ / \
* / + + \
* / -- -- \
* / -- -- \
* / --- --- \
* +-- --+
*/
traps->top = top->y;
traps->left.p1 = *top;
traps->left.p2 = *left;
traps->right.p1 = *top;
traps->right.p2 = *right;
if (right->y < left->y)
traps->bottom = right->y;
else
traps->bottom = left->y;
traps++;
*traps = *(traps - 1);
if (right->y < left->y)
{
traps->top = right->y;
traps->bottom = left->y;
traps->right.p1 = *right;
traps->right.p2 = *left;
}
else
{
traps->top = left->y;
traps->bottom = right->y;
traps->left.p1 = *left;
traps->left.p2 = *right;
}
}
static pixman_trapezoid_t *
convert_triangles (int n_tris, const pixman_triangle_t *tris)
{
pixman_trapezoid_t *traps;
int i;
if (n_tris <= 0)
return NULL;
traps = pixman_malloc_ab (n_tris, 2 * sizeof (pixman_trapezoid_t));
if (!traps)
return NULL;
for (i = 0; i < n_tris; ++i)
triangle_to_trapezoids (&(tris[i]), traps + 2 * i);
return traps;
}
PIXMAN_EXPORT void
pixman_composite_triangles (pixman_op_t op,
pixman_image_t * src,
pixman_image_t * dst,
pixman_format_code_t mask_format,
int x_src,
int y_src,
int x_dst,
int y_dst,
int n_tris,
const pixman_triangle_t * tris)
{
pixman_trapezoid_t *traps;
if ((traps = convert_triangles (n_tris, tris)))
{
pixman_composite_trapezoids (op, src, dst, mask_format,
x_src, y_src, x_dst, y_dst,
n_tris * 2, traps);
free (traps);
}
}
PIXMAN_EXPORT void
pixman_add_triangles (pixman_image_t *image,
int32_t x_off,
int32_t y_off,
int n_tris,
const pixman_triangle_t *tris)
{
pixman_trapezoid_t *traps;
if ((traps = convert_triangles (n_tris, tris)))
{
pixman_add_trapezoids (image, x_off, y_off,
n_tris * 2, traps);
free (traps);
}
}