diff options
Diffstat (limited to 'src/3rdparty/autotrace/pxl-outline.c')
| -rw-r--r-- | src/3rdparty/autotrace/pxl-outline.c | 887 |
1 files changed, 887 insertions, 0 deletions
diff --git a/src/3rdparty/autotrace/pxl-outline.c b/src/3rdparty/autotrace/pxl-outline.c new file mode 100644 index 0000000..6bc5a56 --- /dev/null +++ b/src/3rdparty/autotrace/pxl-outline.c @@ -0,0 +1,887 @@ +/* pxl-outline.c: find the outlines of a bitmap image; each outline is made up of one or more pixels; + and each pixel participates via one or more edges. */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif /* Def: HAVE_CONFIG_H */ + +#include "logreport.h" +#include "types.h" +#include "bitmap.h" +#include "color.h" +#include "bitmap.h" +#include "xstd.h" +#include "pxl-outline.h" +#include <assert.h> + +/* We consider each pixel to consist of four edges, and we travel along + edges, instead of through pixel centers. This is necessary for those + unfortunate times when a single pixel is on both an inside and an + outside outline. + + The numbers chosen here are not arbitrary; the code that figures out + which edge to move to depends on particular values. See the + `TRY_PIXEL' macro in `edge.c'. To emphasize this, I've written in the + numbers we need for each edge value. */ + +typedef enum { + TOP = 1, LEFT = 2, BOTTOM = 3, RIGHT = 0, NO_EDGE = 4 +} edge_type; + +/* This choice is also not arbitrary: starting at the top edge makes the + code find outside outlines before inside ones, which is certainly + what we want. */ +#define START_EDGE top + +typedef enum { + NORTH = 0, NORTHWEST = 1, WEST = 2, SOUTHWEST = 3, SOUTH = 4, + SOUTHEAST = 5, EAST = 6, NORTHEAST = 7 +} direction_type; + +#define NUM_EDGES NO_EDGE + +#define COMPUTE_DELTA(axis, dir) \ + ((dir) % 2 != 0 \ + ? COMPUTE_##axis##_DELTA ((dir) - 1) \ + + COMPUTE_##axis##_DELTA (((dir) + 1) % 8) \ + : COMPUTE_##axis##_DELTA (dir) \ + ) + +#define COMPUTE_ROW_DELTA(dir) \ + ((dir) == NORTH ? -1 : (dir) == SOUTH ? +1 : 0) + +#define COMPUTE_COL_DELTA(dir) \ + ((dir) == WEST ? -1 : (dir) == EAST ? +1 : 0) + +static pixel_outline_type find_one_outline(at_bitmap *, edge_type, unsigned short, unsigned short, at_bitmap *, gboolean, gboolean, at_exception_type *); +static pixel_outline_type find_one_centerline(at_bitmap *, direction_type, unsigned short, unsigned short, at_bitmap *); +static void append_pixel_outline(pixel_outline_list_type *, pixel_outline_type); +static pixel_outline_type new_pixel_outline(void); +static void free_pixel_outline(pixel_outline_type *); +static void concat_pixel_outline(pixel_outline_type *, const pixel_outline_type *); +static void append_outline_pixel(pixel_outline_type *, at_coord); +static gboolean is_marked_edge(edge_type, unsigned short, unsigned short, at_bitmap *); +static gboolean is_outline_edge(edge_type, at_bitmap *, unsigned short, unsigned short, at_color, at_exception_type *); +static gboolean is_unmarked_outline_edge(unsigned short, unsigned short, edge_type, at_bitmap *, at_bitmap *, at_color, at_exception_type *); + +static void mark_edge(edge_type e, unsigned short, unsigned short, at_bitmap *); +/* static edge_type opposite_edge(edge_type); */ + +static gboolean is_marked_dir(unsigned short, unsigned short, direction_type, at_bitmap *); +static gboolean is_other_dir_marked(unsigned short, unsigned short, direction_type, at_bitmap *); +static void mark_dir(unsigned short, unsigned short, direction_type, at_bitmap *); +static gboolean next_unmarked_pixel(unsigned short *, unsigned short *, direction_type *, at_bitmap *, at_bitmap *); + +gboolean is_valid_dir(unsigned short, unsigned short, direction_type, at_bitmap *, at_bitmap *); + +static at_coord next_point(at_bitmap *, edge_type *, unsigned short *, unsigned short *, at_color, gboolean, at_bitmap *, at_exception_type *); +static unsigned num_neighbors(unsigned short, unsigned short, at_bitmap *); + +#define CHECK_FATAL() if (at_exception_got_fatal(exp)) goto cleanup; + +/* We go through a bitmap TOP to BOTTOM, LEFT to RIGHT, looking for each pixel with an unmarked edge + that we consider a starting point of an outline. */ + +pixel_outline_list_type find_outline_pixels(at_bitmap * bitmap, at_color * bg_color, at_progress_func notify_progress, gpointer progress_data, at_testcancel_func test_cancel, gpointer testcancel_data, at_exception_type * exp) +{ + pixel_outline_list_type outline_list; + unsigned short row, col; + at_bitmap *marked = at_bitmap_new(AT_BITMAP_WIDTH(bitmap), AT_BITMAP_HEIGHT(bitmap), 1); + unsigned int max_progress = AT_BITMAP_HEIGHT(bitmap) * AT_BITMAP_WIDTH(bitmap); + + O_LIST_LENGTH(outline_list) = 0; + outline_list.data = NULL; + + for (row = 0; row < AT_BITMAP_HEIGHT(bitmap); row++) { + for (col = 0; col < AT_BITMAP_WIDTH(bitmap); col++) { + edge_type edge; + at_color color; + gboolean is_background; + + if (notify_progress) + notify_progress((gfloat) (row * AT_BITMAP_WIDTH(bitmap) + col) / ((gfloat) max_progress * (gfloat) 3.0), progress_data); + + /* A valid edge can be TOP for an outside outline. + Outside outlines are traced counterclockwise */ + at_bitmap_get_color(bitmap, row, col, &color); + if (!(is_background = (gboolean) (bg_color && at_color_equal(&color, bg_color))) + && is_unmarked_outline_edge(row, col, edge = TOP, bitmap, marked, color, exp)) { + pixel_outline_type outline; + + CHECK_FATAL(); /* FREE(DONE) outline_list */ + + LOG("#%u: (counterclockwise)", O_LIST_LENGTH(outline_list)); + + outline = find_one_outline(bitmap, edge, row, col, marked, FALSE, FALSE, exp); + CHECK_FATAL(); /* FREE(DONE) outline_list */ + + O_CLOCKWISE(outline) = FALSE; + append_pixel_outline(&outline_list, outline); + + LOG(" [%u].\n", O_LENGTH(outline)); + } else + CHECK_FATAL(); /* FREE(DONE) outline_list */ + + /* A valid edge can be BOTTOM for an inside outline. + Inside outlines are traced clockwise */ + if (row != 0) { + at_bitmap_get_color(bitmap, row - 1, col, &color); + if (!(bg_color && at_color_equal(&color, bg_color)) + && is_unmarked_outline_edge(row - 1, col, edge = BOTTOM, bitmap, marked, color, exp)) { + pixel_outline_type outline; + + CHECK_FATAL(); /* FREE(DONE) outline_list */ + + /* This lines are for debugging only: */ + if (is_background) { + LOG("#%u: (clockwise)", O_LIST_LENGTH(outline_list)); + + outline = find_one_outline(bitmap, edge, row - 1, col, marked, TRUE, FALSE, exp); + CHECK_FATAL(); /* FREE(DONE) outline_list */ + + O_CLOCKWISE(outline) = TRUE; + append_pixel_outline(&outline_list, outline); + + LOG(" [%u].\n", O_LENGTH(outline)); + } else { + outline = find_one_outline(bitmap, edge, row - 1, col, marked, TRUE, TRUE, exp); + CHECK_FATAL(); /* FREE(DONE) outline_list */ + } + } else + CHECK_FATAL(); /* FREE(DONE) outline_list */ + } + if (test_cancel && test_cancel(testcancel_data)) { + free_pixel_outline_list(&outline_list); + goto cleanup; + } + } + } +cleanup: + at_bitmap_free(marked); + if (at_exception_got_fatal(exp)) + free_pixel_outline_list(&outline_list); + return outline_list; +} + +/* We calculate one single outline here. We pass the position of the starting pixel and the + starting edge. All edges we track along will be marked and the outline pixels are appended + to the coordinate list. */ + +static pixel_outline_type find_one_outline(at_bitmap * bitmap, edge_type original_edge, unsigned short original_row, unsigned short original_col, at_bitmap * marked, gboolean clockwise, gboolean ignore, at_exception_type * exp) +{ + pixel_outline_type outline; + unsigned short row = original_row, col = original_col; + edge_type edge = original_edge; + at_coord pos; + + pos.x = col + ((edge == RIGHT) || (edge == BOTTOM) ? 1 : 0); + pos.y = AT_BITMAP_HEIGHT(bitmap) - row - 1 + ((edge == TOP) || (edge == RIGHT) ? 1 : 0); + + if (!ignore) + outline = new_pixel_outline(); + at_bitmap_get_color(bitmap, row, col, &outline.color); + + do { + /* Put this edge into the output list */ + if (!ignore) { + LOG(" (%d,%d)", pos.x, pos.y); + append_outline_pixel(&outline, pos); + } + + mark_edge(edge, row, col, marked); + pos = next_point(bitmap, &edge, &row, &col, outline.color, clockwise, marked, exp); + CHECK_FATAL(); + } + while (edge != NO_EDGE); + +cleanup: + if (at_exception_got_fatal(exp)) + free_pixel_outline(&outline); + return outline; +} + +gboolean is_valid_dir(unsigned short row, unsigned short col, direction_type dir, at_bitmap * bitmap, at_bitmap * marked) +{ + + at_color c; + + if ((COMPUTE_DELTA(ROW, dir) + row < 0) || (COMPUTE_DELTA(COL, dir) + col < 0)) + return FALSE; // Must not call at_bitmap_get_color() with negative row or col. + + at_bitmap_get_color(bitmap, COMPUTE_DELTA(ROW, dir) + row, COMPUTE_DELTA(COL, dir) + col, &c); + return ((gboolean) (!is_marked_dir(row, col, dir, marked) + && COMPUTE_DELTA(ROW, dir) + row > 0 && COMPUTE_DELTA(COL, dir) + col > 0 && AT_BITMAP_VALID_PIXEL(bitmap, COMPUTE_DELTA(ROW, dir) + row, COMPUTE_DELTA(COL, dir) + col) + && at_bitmap_equal_color(bitmap, row, col, &c))); +} + +pixel_outline_list_type find_centerline_pixels(at_bitmap * bitmap, at_color bg_color, at_progress_func notify_progress, gpointer progress_data, at_testcancel_func test_cancel, gpointer testcancel_data, at_exception_type * exp) +{ + pixel_outline_list_type outline_list; + signed short row, col; + at_bitmap *marked = at_bitmap_new(AT_BITMAP_WIDTH(bitmap), AT_BITMAP_HEIGHT(bitmap), 1); + unsigned int max_progress = AT_BITMAP_HEIGHT(bitmap) * AT_BITMAP_WIDTH(bitmap); + + O_LIST_LENGTH(outline_list) = 0; + outline_list.data = NULL; + + for (row = 0; row < AT_BITMAP_HEIGHT(bitmap); row++) { + for (col = 0; col < AT_BITMAP_WIDTH(bitmap);) { + direction_type dir = EAST; + pixel_outline_type outline; + gboolean clockwise = FALSE; + + if (notify_progress) + notify_progress((gfloat) (row * AT_BITMAP_WIDTH(bitmap) + col) / ((gfloat) max_progress * (gfloat) 3.0), progress_data); + + if (at_bitmap_equal_color(bitmap, row, col, &bg_color)) { + col++; + continue; + } + + if (!is_valid_dir(row, col, dir, bitmap, marked) + || (!is_valid_dir(COMPUTE_DELTA(ROW, dir) + row, COMPUTE_DELTA(COL, dir) + col, dir, bitmap, marked) + && num_neighbors(row, col, bitmap) > 2) + || num_neighbors(row, col, bitmap) > 4 || num_neighbors(COMPUTE_DELTA(ROW, dir) + row, COMPUTE_DELTA(COL, dir) + col, bitmap) > 4 || (is_other_dir_marked(row, col, dir, marked) + && is_other_dir_marked(row + COMPUTE_DELTA(ROW, dir), col + COMPUTE_DELTA(COL, dir), dir, marked))) { + dir = SOUTHEAST; + if (!is_valid_dir(row, col, dir, bitmap, marked) + || (!is_valid_dir(COMPUTE_DELTA(ROW, dir) + row, COMPUTE_DELTA(COL, dir) + col, dir, bitmap, marked) + && num_neighbors(row, col, bitmap) > 2) + || num_neighbors(row, col, bitmap) > 4 || num_neighbors(COMPUTE_DELTA(ROW, dir) + row, COMPUTE_DELTA(COL, dir) + col, bitmap) > 4 || (is_other_dir_marked(row, col, dir, marked) + && is_other_dir_marked(row + COMPUTE_DELTA(ROW, dir), col + COMPUTE_DELTA(COL, dir), dir, marked))) { + dir = SOUTH; + if (!is_valid_dir(row, col, dir, bitmap, marked) + || (!is_valid_dir(COMPUTE_DELTA(ROW, dir) + row, COMPUTE_DELTA(COL, dir) + col, dir, bitmap, marked) + && num_neighbors(row, col, bitmap) > 2) + || num_neighbors(row, col, bitmap) > 4 || num_neighbors(COMPUTE_DELTA(ROW, dir) + row, COMPUTE_DELTA(COL, dir) + col, bitmap) > 4 || (is_other_dir_marked(row, col, dir, marked) + && is_other_dir_marked(row + COMPUTE_DELTA(ROW, dir), col + COMPUTE_DELTA(COL, dir), dir, marked))) { + dir = SOUTHWEST; + if (!is_valid_dir(row, col, dir, bitmap, marked) + || (!is_valid_dir(COMPUTE_DELTA(ROW, dir) + row, COMPUTE_DELTA(COL, dir) + col, dir, bitmap, marked) + && num_neighbors(row, col, bitmap) > 2) + || num_neighbors(row, col, bitmap) > 4 || num_neighbors(COMPUTE_DELTA(ROW, dir) + row, COMPUTE_DELTA(COL, dir) + col, bitmap) > 4 || (is_other_dir_marked(row, col, dir, marked) + && is_other_dir_marked(row + COMPUTE_DELTA(ROW, dir), col + COMPUTE_DELTA(COL, dir), dir, marked))) { + col++; + continue; + } + } + } + } + + LOG("#%u: (%sclockwise) ", O_LIST_LENGTH(outline_list), clockwise ? "" : "counter"); + + outline = find_one_centerline(bitmap, dir, row, col, marked); + + /* If the outline is open (i.e., we didn't return to the + starting pixel), search from the starting pixel in the + opposite direction and concatenate the two outlines. */ + + if (outline.open) { + pixel_outline_type partial_outline; + gboolean okay = FALSE; + + if (dir == EAST) { + dir = SOUTH; + if (!(okay = is_valid_dir(row, col, dir, bitmap, marked))) { + dir = SOUTHWEST; + if (!(okay = is_valid_dir(row, col, dir, bitmap, marked))) { + dir = SOUTHEAST; + okay = is_valid_dir(row, col, dir, bitmap, marked); + } + } + } else if (dir == SOUTHEAST) { + dir = SOUTHWEST; + if (!(okay = is_valid_dir(row, col, dir, bitmap, marked))) { + dir = EAST; + if (!(okay = is_valid_dir(row, col, dir, bitmap, marked))) { + dir = SOUTH; + okay = is_valid_dir(row, col, dir, bitmap, marked); + } + } + } else if (dir == SOUTH) { + dir = EAST; + if (!(okay = is_valid_dir(row, col, dir, bitmap, marked))) { + dir = SOUTHEAST; + if (!(okay = is_valid_dir(row, col, dir, bitmap, marked))) { + dir = SOUTHWEST; + okay = is_valid_dir(row, col, dir, bitmap, marked); + } + } + } else if (dir == SOUTHWEST) { + dir = SOUTHEAST; + if (!(okay = is_valid_dir(row, col, dir, bitmap, marked))) { + dir = EAST; + if (!(okay = is_valid_dir(row, col, dir, bitmap, marked))) { + dir = SOUTH; + okay = is_valid_dir(row, col, dir, bitmap, marked); + } + } + } + if (okay) { + partial_outline = find_one_centerline(bitmap, dir, row, col, marked); + concat_pixel_outline(&outline, &partial_outline); + if (partial_outline.data) + free(partial_outline.data); + } else + col++; + } + + /* Outside outlines will start at a top edge, and move + counterclockwise, and inside outlines will start at a + bottom edge, and move clockwise. This happens because of + the order in which we look at the edges. */ + O_CLOCKWISE(outline) = clockwise; + if (O_LENGTH(outline) > 1) + append_pixel_outline(&outline_list, outline); + LOG("(%s)", (outline.open ? " open" : " closed")); + LOG(" [%u].\n", O_LENGTH(outline)); + if (O_LENGTH(outline) == 1) + free_pixel_outline(&outline); + } + } + if (test_cancel && test_cancel(testcancel_data)) { + if (O_LIST_LENGTH(outline_list) != 0) + free_pixel_outline_list(&outline_list); + goto cleanup; + } +cleanup: + at_bitmap_free(marked); + return outline_list; +} + +static pixel_outline_type find_one_centerline(at_bitmap * bitmap, direction_type search_dir, unsigned short original_row, unsigned short original_col, at_bitmap * marked) +{ + pixel_outline_type outline = new_pixel_outline(); + direction_type original_dir = search_dir; + unsigned short row = original_row, col = original_col; + unsigned short prev_row, prev_col; + at_coord pos; + + outline.open = FALSE; + at_bitmap_get_color(bitmap, row, col, &outline.color); + + /* Add the starting pixel to the output list, changing from bitmap + to Cartesian coordinates and specifying the left edge so that + the coordinates won't be adjusted. */ + pos.x = col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - row - 1; + LOG(" (%d,%d)", pos.x, pos.y); + append_outline_pixel(&outline, pos); + + for (;;) { + prev_row = row; + prev_col = col; + + /* If there is no adjacent, unmarked pixel, we can't proceed + any further, so return an open outline. */ + if (!next_unmarked_pixel(&row, &col, &search_dir, bitmap, marked)) { + outline.open = TRUE; + break; + } + + /* If we've moved to a new pixel, mark all edges of the previous + pixel so that it won't be revisited. */ + if (!(prev_row == original_row && prev_col == original_col)) + mark_dir(prev_row, prev_col, search_dir, marked); + mark_dir(row, col, (direction_type) ((search_dir + 4) % 8), marked); + + /* If we've returned to the starting pixel, we're done. */ + if (row == original_row && col == original_col) + break; + + /* Add the new pixel to the output list. */ + pos.x = col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - row - 1; + LOG(" (%d,%d)", pos.x, pos.y); + append_outline_pixel(&outline, pos); + } + mark_dir(original_row, original_col, original_dir, marked); + return outline; +} + +/* Add an outline to an outline list. */ + +static void append_pixel_outline(pixel_outline_list_type * outline_list, pixel_outline_type outline) +{ + O_LIST_LENGTH(*outline_list)++; + XREALLOC(outline_list->data, outline_list->length * sizeof(pixel_outline_type)); + O_LIST_OUTLINE(*outline_list, O_LIST_LENGTH(*outline_list) - 1) = outline; +} + +/* Free the list of outline lists. */ + +void free_pixel_outline_list(pixel_outline_list_type * outline_list) +{ + unsigned this_outline; + + for (this_outline = 0; this_outline < outline_list->length; this_outline++) { + pixel_outline_type o = outline_list->data[this_outline]; + free_pixel_outline(&o); + } + free(outline_list->data); + outline_list->data = NULL; + outline_list->length = 0; +} + +/* Return an empty list of pixels. */ + +static pixel_outline_type new_pixel_outline(void) +{ + pixel_outline_type pixel_outline; + + O_LENGTH(pixel_outline) = 0; + pixel_outline.data = NULL; + pixel_outline.open = FALSE; + + return pixel_outline; +} + +static void free_pixel_outline(pixel_outline_type * outline) +{ + free(outline->data); + outline->data = NULL; + outline->length = 0; +} + +/* Concatenate two pixel lists. The two lists are assumed to have the + same starting pixel and to proceed in opposite directions therefrom. */ + +static void concat_pixel_outline(pixel_outline_type * o1, const pixel_outline_type * o2) +{ + int src, dst; + unsigned o1_length, o2_length; + if (!o1 || !o2 || O_LENGTH(*o2) <= 1) + return; + + o1_length = O_LENGTH(*o1); + o2_length = O_LENGTH(*o2); + O_LENGTH(*o1) += o2_length - 1; + /* Resize o1 to the sum of the lengths of o1 and o2 minus one (because + the two lists are assumed to share the same starting pixel). */ + XREALLOC(o1->data, O_LENGTH(*o1) * sizeof(at_coord)); + /* Shift the contents of o1 to the end of the new array to make room + to prepend o2. */ + for (src = o1_length - 1, dst = O_LENGTH(*o1) - 1; src >= 0; src--, dst--) + O_COORDINATE(*o1, dst) = O_COORDINATE(*o1, src); + /* Prepend the contents of o2 (in reverse order) to o1. */ + for (src = o2_length - 1, dst = 0; src > 0; src--, dst++) + O_COORDINATE(*o1, dst) = O_COORDINATE(*o2, src); +} + +/* Add a point to the pixel list. */ + +static void append_outline_pixel(pixel_outline_type * o, at_coord c) +{ + O_LENGTH(*o)++; + XREALLOC(o->data, O_LENGTH(*o) * sizeof(at_coord)); + O_COORDINATE(*o, O_LENGTH(*o) - 1) = c; +} + +/* Is this really an edge and is it still unmarked? */ + +static gboolean is_unmarked_outline_edge(unsigned short row, unsigned short col, edge_type edge, at_bitmap * bitmap, at_bitmap * marked, at_color color, at_exception_type * exp) +{ + return (gboolean) (!is_marked_edge(edge, row, col, marked) + && is_outline_edge(edge, bitmap, row, col, color, exp)); +} + +/* We check to see if the edge of the pixel at position ROW and COL + is an outline edge */ + +static gboolean is_outline_edge(edge_type edge, at_bitmap * bitmap, unsigned short row, unsigned short col, at_color color, at_exception_type * exp) +{ + /* If this pixel isn't of the same color, it's not part of the outline. */ + if (!at_bitmap_equal_color(bitmap, row, col, &color)) + return FALSE; + + switch (edge) { + case LEFT: + return (gboolean) (col == 0 || !at_bitmap_equal_color(bitmap, row, col - 1, &color)); + case TOP: + return (gboolean) (row == 0 || !at_bitmap_equal_color(bitmap, row - 1, col, &color)); + + case RIGHT: + return (gboolean) (col == AT_BITMAP_WIDTH(bitmap) - 1 || !at_bitmap_equal_color(bitmap, row, col + 1, &color)); + + case BOTTOM: + return (gboolean) (row == AT_BITMAP_HEIGHT(bitmap) - 1 || !at_bitmap_equal_color(bitmap, row + 1, col, &color)); + + case NO_EDGE: + g_assert_not_reached(); + default: + g_assert_not_reached(); + } + return FALSE; /* NOT REACHED */ +} + +/* If EDGE is not already marked, we mark it; otherwise, it's a fatal error. + The position ROW and COL should be inside the bitmap MARKED. EDGE can be + NO_EDGE. */ + +static void mark_edge(edge_type edge, unsigned short row, unsigned short col, at_bitmap * marked) +{ + *AT_BITMAP_PIXEL(marked, row, col) |= 1 << edge; +} + +/* Mark the direction of the pixel ROW/COL in MARKED. */ + +static void mark_dir(unsigned short row, unsigned short col, direction_type dir, at_bitmap * marked) +{ + *AT_BITMAP_PIXEL(marked, row, col) |= 1 << dir; +} + +/* Test if the direction of pixel at ROW/COL in MARKED is marked. */ + +static gboolean is_marked_dir(unsigned short row, unsigned short col, direction_type dir, at_bitmap * marked) +{ + return (gboolean) ((*AT_BITMAP_PIXEL(marked, row, col) & 1 << dir) != 0); +} + +static gboolean is_other_dir_marked(unsigned short row, unsigned short col, direction_type dir, at_bitmap * marked) +{ + return (gboolean) ((*AT_BITMAP_PIXEL(marked, row, col) & (255 - (1 << dir) - (1 << ((dir + 4) % 8)))) != 0); +} + +static gboolean next_unmarked_pixel(unsigned short *row, unsigned short *col, direction_type * dir, at_bitmap * bitmap, at_bitmap * marked) +{ + unsigned short orig_row = *row, orig_col = *col; + direction_type orig_dir = *dir, test_dir = *dir; + + do { + if (is_valid_dir(orig_row, orig_col, test_dir, bitmap, marked)) { + *row = orig_row + COMPUTE_DELTA(ROW, test_dir); + *col = orig_col + COMPUTE_DELTA(COL, test_dir); + *dir = test_dir; + break; + } + + if (orig_dir == test_dir) + test_dir = (direction_type) ((orig_dir + 2) % 8); + else if ((orig_dir + 2) % 8 == test_dir) + test_dir = (direction_type) ((orig_dir + 6) % 8); + else if ((orig_dir + 6) % 8 == test_dir) + test_dir = (direction_type) ((orig_dir + 1) % 8); + else if ((orig_dir + 1) % 8 == test_dir) + test_dir = (direction_type) ((orig_dir + 7) % 8); + else if ((orig_dir + 7) % 8 == test_dir) + test_dir = (direction_type) ((orig_dir + 3) % 8); + else if ((orig_dir + 3) % 8 == test_dir) + test_dir = (direction_type) ((orig_dir + 5) % 8); + else if ((orig_dir + 5) % 8 == test_dir) + break; + } + while (1); + if ((*row != orig_row || *col != orig_col) && (!(is_other_dir_marked(orig_row, orig_col, test_dir, marked) + && is_other_dir_marked(orig_row + COMPUTE_DELTA(ROW, test_dir), orig_col + COMPUTE_DELTA(COL, test_dir), test_dir, marked)))) + return TRUE; + else + return FALSE; +} + +/* Return the number of pixels adjacent to pixel ROW/COL that are black. */ + +static unsigned num_neighbors(unsigned short row, unsigned short col, at_bitmap * bitmap) +{ + unsigned dir, count = 0; + at_color color; + + at_bitmap_get_color(bitmap, row, col, &color); + for (dir = NORTH; dir <= NORTHEAST; dir++) { + int delta_r = COMPUTE_DELTA(ROW, dir); + int delta_c = COMPUTE_DELTA(COL, dir); + unsigned int test_row = row + delta_r; + unsigned int test_col = col + delta_c; + if (AT_BITMAP_VALID_PIXEL(bitmap, test_row, test_col) + && at_bitmap_equal_color(bitmap, test_row, test_col, &color)) + ++count; + } + return count; +} + +/* Test if the edge EDGE at ROW/COL in MARKED is marked. */ + +static gboolean is_marked_edge(edge_type edge, unsigned short row, unsigned short col, at_bitmap * marked) +{ + return (gboolean) (edge == NO_EDGE ? FALSE : (*AT_BITMAP_PIXEL(marked, row, col) & (1 << edge)) != 0); +} + +static at_coord next_point(at_bitmap * bitmap, edge_type * edge, unsigned short *row, unsigned short *col, at_color color, gboolean clockwise, at_bitmap * marked, at_exception_type * exp) +{ + at_coord pos = { 0, 0 }; + + if (!clockwise) + switch (*edge) { + case TOP: + /* WEST */ + if ((*col >= 1 && !is_marked_edge(TOP, *row, *col - 1, marked) + && is_outline_edge(TOP, bitmap, *row, *col - 1, color, exp))) { + /**edge = TOP;*/ + (*col)--; + pos.x = *col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row; + break; + } + CHECK_FATAL(); + /* NORTHWEST */ + if ((*col >= 1 && *row >= 1 && !is_marked_edge(RIGHT, *row - 1, *col - 1, marked) + && is_outline_edge(RIGHT, bitmap, *row - 1, *col - 1, color, exp)) && !(is_marked_edge(LEFT, *row - 1, *col, marked) && is_marked_edge(TOP, *row, *col - 1, marked)) && !(is_marked_edge(BOTTOM, *row - 1, *col, marked) && is_marked_edge(RIGHT, *row, *col - 1, marked))) { + *edge = RIGHT; + (*col)--; + (*row)--; + pos.x = *col + 1; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row; + break; + } + CHECK_FATAL(); + if ((!is_marked_edge(LEFT, *row, *col, marked) + && is_outline_edge(LEFT, bitmap, *row, *col, color, exp))) { + *edge = LEFT; + pos.x = *col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row - 1; + break; + } + CHECK_FATAL(); + *edge = NO_EDGE; + break; + case RIGHT: + /* NORTH */ + if ((*row >= 1 && !is_marked_edge(RIGHT, *row - 1, *col, marked) + && is_outline_edge(RIGHT, bitmap, *row - 1, *col, color, exp))) { + /**edge = RIGHT;*/ + (*row)--; + pos.x = *col + 1; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row; + break; + } + CHECK_FATAL(); + /* NORTHEAST */ + if ((*col + 1 < AT_BITMAP_WIDTH(marked) && *row >= 1 && !is_marked_edge(BOTTOM, *row - 1, *col + 1, marked) + && is_outline_edge(BOTTOM, bitmap, *row - 1, *col + 1, color, exp)) && !(is_marked_edge(LEFT, *row, *col + 1, marked) && is_marked_edge(BOTTOM, *row - 1, *col, marked)) && !(is_marked_edge(TOP, *row, *col + 1, marked) && is_marked_edge(RIGHT, *row - 1, *col, marked))) { + *edge = BOTTOM; + (*col)++; + (*row)--; + pos.x = *col + 1; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row - 1; + break; + } + CHECK_FATAL(); + if ((!is_marked_edge(TOP, *row, *col, marked) + && is_outline_edge(TOP, bitmap, *row, *col, color, exp))) { + *edge = TOP; + pos.x = *col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row; + break; + } + CHECK_FATAL(); + *edge = NO_EDGE; + break; + case BOTTOM: + /* EAST */ + if ((*col + 1 < AT_BITMAP_WIDTH(marked) + && !is_marked_edge(BOTTOM, *row, *col + 1, marked) + && is_outline_edge(BOTTOM, bitmap, *row, *col + 1, color, exp))) { + /**edge = BOTTOM;*/ + (*col)++; + pos.x = *col + 1; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row - 1; + break; + } + CHECK_FATAL(); + /* SOUTHEAST */ + if ((*col + 1 < AT_BITMAP_WIDTH(marked) && *row + 1 < AT_BITMAP_HEIGHT(marked) + && !is_marked_edge(LEFT, *row + 1, *col + 1, marked) + && is_outline_edge(LEFT, bitmap, *row + 1, *col + 1, color, exp)) && !(is_marked_edge(TOP, *row + 1, *col, marked) && is_marked_edge(LEFT, *row, *col + 1, marked)) && !(is_marked_edge(RIGHT, *row + 1, *col, marked) && is_marked_edge(BOTTOM, *row, *col + 1, marked))) { + *edge = LEFT; + (*col)++; + (*row)++; + pos.x = *col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row - 1; + break; + } + CHECK_FATAL(); + if ((!is_marked_edge(RIGHT, *row, *col, marked) + && is_outline_edge(RIGHT, bitmap, *row, *col, color, exp))) { + *edge = RIGHT; + pos.x = *col + 1; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row; + break; + } + CHECK_FATAL(); + *edge = NO_EDGE; + break; + case LEFT: + /* SOUTH */ + if ((*row + 1 < AT_BITMAP_HEIGHT(marked) + && !is_marked_edge(LEFT, *row + 1, *col, marked) + && is_outline_edge(LEFT, bitmap, *row + 1, *col, color, exp))) { + /**edge = LEFT;*/ + (*row)++; + pos.x = *col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row - 1; + break; + } + CHECK_FATAL(); + /* SOUTHWEST */ + if ((*col >= 1 && *row + 1 < AT_BITMAP_HEIGHT(marked) + && !is_marked_edge(TOP, *row + 1, *col - 1, marked) + && is_outline_edge(TOP, bitmap, *row + 1, *col - 1, color, exp)) && !(is_marked_edge(RIGHT, *row, *col - 1, marked) && is_marked_edge(TOP, *row + 1, *col, marked)) && !(is_marked_edge(BOTTOM, *row, *col - 1, marked) && is_marked_edge(LEFT, *row + 1, *col, marked))) { + *edge = TOP; + (*col)--; + (*row)++; + pos.x = *col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row; + break; + } + CHECK_FATAL(); + if ((!is_marked_edge(BOTTOM, *row, *col, marked) + && is_outline_edge(BOTTOM, bitmap, *row, *col, color, exp))) { + *edge = BOTTOM; + pos.x = *col + 1; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row - 1; + break; + } + CHECK_FATAL(); + case NO_EDGE: + default: + *edge = NO_EDGE; + break; + } else + switch (*edge) { + case TOP: + if ((!is_marked_edge(LEFT, *row, *col, marked) + && is_outline_edge(LEFT, bitmap, *row, *col, color, exp))) { + *edge = LEFT; + pos.x = *col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row - 1; + break; + } + CHECK_FATAL(); + /* WEST */ + if ((*col >= 1 && !is_marked_edge(TOP, *row, *col - 1, marked) + && is_outline_edge(TOP, bitmap, *row, *col - 1, color, exp))) { + /**edge = TOP;*/ + (*col)--; + pos.x = *col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row; + break; + } + CHECK_FATAL(); + /* NORTHWEST */ + if ((*col >= 1 && *row >= 1 && !is_marked_edge(RIGHT, *row - 1, *col - 1, marked) + && is_outline_edge(RIGHT, bitmap, *row - 1, *col - 1, color, exp))) { + *edge = RIGHT; + (*col)--; + (*row)--; + pos.x = *col + 1; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row; + break; + } + CHECK_FATAL(); + *edge = NO_EDGE; + break; + case RIGHT: + if ((!is_marked_edge(TOP, *row, *col, marked) + && is_outline_edge(TOP, bitmap, *row, *col, color, exp))) { + *edge = TOP; + pos.x = *col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row; + break; + } + CHECK_FATAL(); + /* NORTH */ + if ((*row >= 1 && !is_marked_edge(RIGHT, *row - 1, *col, marked) + && is_outline_edge(RIGHT, bitmap, *row - 1, *col, color, exp))) { + /**edge = RIGHT;*/ + (*row)--; + pos.x = *col + 1; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row; + break; + } + CHECK_FATAL(); + /* NORTHEAST */ + if ((*col + 1 < AT_BITMAP_WIDTH(marked) && *row >= 1 && !is_marked_edge(BOTTOM, *row - 1, *col + 1, marked) + && is_outline_edge(BOTTOM, bitmap, *row - 1, *col + 1, color, exp))) { + *edge = BOTTOM; + (*col)++; + (*row)--; + pos.x = *col + 1; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row - 1; + break; + } + CHECK_FATAL(); + *edge = NO_EDGE; + break; + case BOTTOM: + if ((!is_marked_edge(RIGHT, *row, *col, marked) + && is_outline_edge(RIGHT, bitmap, *row, *col, color, exp))) { + *edge = RIGHT; + pos.x = *col + 1; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row; + break; + } + CHECK_FATAL(); + /* EAST */ + if ((*col + 1 < AT_BITMAP_WIDTH(marked) + && !is_marked_edge(BOTTOM, *row, *col + 1, marked) + && is_outline_edge(BOTTOM, bitmap, *row, *col + 1, color, exp))) { + /**edge = BOTTOM;*/ + (*col)++; + pos.x = *col + 1; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row - 1; + break; + } + CHECK_FATAL(); + /* SOUTHEAST */ + if ((*col + 1 < AT_BITMAP_WIDTH(marked) && *row + 1 < AT_BITMAP_HEIGHT(marked) + && !is_marked_edge(LEFT, *row + 1, *col + 1, marked) + && is_outline_edge(LEFT, bitmap, *row + 1, *col + 1, color, exp))) { + *edge = LEFT; + (*col)++; + (*row)++; + pos.x = *col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row - 1; + break; + } + CHECK_FATAL(); + *edge = NO_EDGE; + break; + case LEFT: + if ((!is_marked_edge(BOTTOM, *row, *col, marked) + && is_outline_edge(BOTTOM, bitmap, *row, *col, color, exp))) { + *edge = BOTTOM; + pos.x = *col + 1; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row - 1; + break; + } + CHECK_FATAL(); + /* SOUTH */ + if ((*row + 1 < AT_BITMAP_HEIGHT(marked) + && !is_marked_edge(LEFT, *row + 1, *col, marked) + && is_outline_edge(LEFT, bitmap, *row + 1, *col, color, exp))) { + /**edge = LEFT;*/ + (*row)++; + pos.x = *col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row - 1; + break; + } + CHECK_FATAL(); + /* SOUTHWEST */ + if ((*col >= 1 && *row + 1 < AT_BITMAP_HEIGHT(marked) + && !is_marked_edge(TOP, *row + 1, *col - 1, marked) + && is_outline_edge(TOP, bitmap, *row + 1, *col - 1, color, exp))) { + *edge = TOP; + (*col)--; + (*row)++; + pos.x = *col; + pos.y = AT_BITMAP_HEIGHT(bitmap) - *row; + break; + } + CHECK_FATAL(); + case NO_EDGE: + default: + *edge = NO_EDGE; + break; + } +cleanup: + return (pos); +} |