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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 <stdio.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 * 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, |
| pixman_trap_t * traps) |
| { |
| int bpp; |
| int width; |
| 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); |
| |
| width = image->bits.width; |
| 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 width; |
| int height; |
| |
| pixman_fixed_t x_off_fixed; |
| 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; |
| |
| width = image->bits.width; |
| 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); |
| |
| 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); |
| } |
| } |