diff options
Diffstat (limited to 'gfx/cairo/libpixman/src/pixman-trap.c')
| -rw-r--r-- | gfx/cairo/libpixman/src/pixman-trap.c | 711 |
1 files changed, 711 insertions, 0 deletions
diff --git a/gfx/cairo/libpixman/src/pixman-trap.c b/gfx/cairo/libpixman/src/pixman-trap.c new file mode 100644 index 0000000000..7560405ee2 --- /dev/null +++ b/gfx/cairo/libpixman/src/pixman-trap.c @@ -0,0 +1,711 @@ +/* + * 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) == 0xffff8000) + { + 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); + } +} |