aseprite/src/raster/algofill.cpp
2014-12-21 15:22:41 +01:00

401 lines
10 KiB
C++

// The floodfill routine.
// By Shawn Hargreaves.
// Adapted to Aseprite by David Capello
// Added non-contiguous mode by David Capello
//
// This file is released under the terms of the MIT license.
// Read LICENSE.txt for more information.
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "raster/algo.h"
#include "raster/image.h"
#include "raster/primitives.h"
#include <climits>
#include <cmath>
#include <vector>
namespace raster {
struct FLOODED_LINE { // store segments which have been flooded
short flags; // status of the segment
short lpos, rpos; // left and right ends of segment
short y; // y coordinate of the segment
int next; // linked list if several per line
};
/* Note: a 'short' is not sufficient for 'next' above in some corner cases. */
static std::vector<FLOODED_LINE> flood_buf;
static int flood_count; /* number of flooded segments */
#define FLOOD_IN_USE 1
#define FLOOD_TODO_ABOVE 2
#define FLOOD_TODO_BELOW 4
#define FLOOD_LINE(c) (&flood_buf[c])
static inline bool color_equal_32(color_t c1, color_t c2, int tolerance)
{
if (tolerance == 0)
return (c1 == c2) || (rgba_geta(c1) == 0 && rgba_geta(c2) == 0);
else {
int r1 = rgba_getr(c1);
int g1 = rgba_getg(c1);
int b1 = rgba_getb(c1);
int a1 = rgba_geta(c1);
int r2 = rgba_getr(c2);
int g2 = rgba_getg(c2);
int b2 = rgba_getb(c2);
int a2 = rgba_geta(c2);
if (a1 == 0 && a2 == 0)
return true;
return ((ABS(r1-r2) <= tolerance) &&
(ABS(g1-g2) <= tolerance) &&
(ABS(b1-b2) <= tolerance) &&
(ABS(a1-a2) <= tolerance));
}
}
static inline bool color_equal_16(color_t c1, color_t c2, int tolerance)
{
if (tolerance == 0)
return (c1 == c2) || (graya_geta(c1) == 0 && graya_geta(c2) == 0);
else {
int k1 = graya_getv(c1);
int a1 = graya_geta(c1);
int k2 = graya_getv(c2);
int a2 = graya_geta(c2);
if (a1 == 0 && a2 == 0)
return true;
return ((ABS(k1-k2) <= tolerance) &&
(ABS(a1-a2) <= tolerance));
}
}
static inline bool color_equal_8(color_t c1, color_t c2, int tolerance)
{
if (tolerance == 0)
return (c1 == c2);
else
return ABS((int)c1 - (int)c2) <= tolerance;
}
template<typename ImageTraits>
static inline bool color_equal(color_t c1, color_t c2, int tolerance)
{
static_assert(false && sizeof(ImageTraits), "Invalid color comparison");
return false;
}
template<>
inline bool color_equal<RgbTraits>(color_t c1, color_t c2, int tolerance)
{
return color_equal_32(c1, c2, tolerance);
}
template<>
inline bool color_equal<GrayscaleTraits>(color_t c1, color_t c2, int tolerance)
{
return color_equal_16(c1, c2, tolerance);
}
template<>
inline bool color_equal<IndexedTraits>(color_t c1, color_t c2, int tolerance)
{
return color_equal_8(c1, c2, tolerance);
}
/* flooder:
* Fills a horizontal line around the specified position, and adds it
* to the list of drawn segments. Returns the first x coordinate after
* the part of the line which it has dealt with.
*/
static int flooder(Image *image, int x, int y,
const gfx::Rect& bounds,
color_t src_color, int tolerance, void *data, AlgoHLine proc)
{
FLOODED_LINE *p;
int left = 0, right = 0;
int c;
switch (image->pixelFormat()) {
case IMAGE_RGB:
{
uint32_t* address = reinterpret_cast<uint32_t*>(image->getPixelAddress(0, y));
// Check start pixel
if (!color_equal_32((int)*(address+x), src_color, tolerance))
return x+1;
// Work left from starting point
for (left=x-1; left>=bounds.x; left--) {
if (!color_equal_32((int)*(address+left), src_color, tolerance))
break;
}
// Work right from starting point
for (right=x+1; right<bounds.x2(); right++) {
if (!color_equal_32((int)*(address+right), src_color, tolerance))
break;
}
}
break;
case IMAGE_GRAYSCALE:
{
uint16_t* address = reinterpret_cast<uint16_t*>(image->getPixelAddress(0, y));
// Check start pixel
if (!color_equal_16((int)*(address+x), src_color, tolerance))
return x+1;
// Work left from starting point
for (left=x-1; left>=bounds.x; left--) {
if (!color_equal_16((int)*(address+left), src_color, tolerance))
break;
}
// Work right from starting point
for (right=x+1; right<bounds.x2(); right++) {
if (!color_equal_16((int)*(address+right), src_color, tolerance))
break;
}
}
break;
case IMAGE_INDEXED:
{
uint8_t* address = image->getPixelAddress(0, y);
// Check start pixel
if (!color_equal_8((int)*(address+x), src_color, tolerance))
return x+1;
// Work left from starting point
for (left=x-1; left>=bounds.x; left--) {
if (!color_equal_8((int)*(address+left), src_color, tolerance))
break;
}
// Work right from starting point
for (right=x+1; right<bounds.x2(); right++) {
if (!color_equal_8((int)*(address+right), src_color, tolerance))
break;
}
}
break;
default:
// Check start pixel
if (get_pixel(image, x, y) != src_color)
return x+1;
// Work left from starting point
for (left=x-1; left>=bounds.x; left--) {
if (get_pixel(image, left, y) != src_color)
break;
}
// Work right from starting point
for (right=x+1; right<bounds.x2(); right++) {
if (get_pixel(image, right, y) != src_color)
break;
}
break;
}
left++;
right--;
/* draw the line */
(*proc)(left, y, right, data);
/* store it in the list of flooded segments */
c = y;
p = FLOOD_LINE(c);
if (p->flags) {
while (p->next) {
c = p->next;
p = FLOOD_LINE(c);
}
p->next = c = flood_count++;
flood_buf.resize(flood_count);
p = FLOOD_LINE(c);
}
p->flags = FLOOD_IN_USE;
p->lpos = left;
p->rpos = right;
p->y = y;
p->next = 0;
if (y > bounds.y)
p->flags |= FLOOD_TODO_ABOVE;
if (y+1 < bounds.y2())
p->flags |= FLOOD_TODO_BELOW;
return right+2;
}
/* check_flood_line:
* Checks a line segment, using the scratch buffer is to store a list of
* segments which have already been drawn in order to minimise the required
* number of tests.
*/
static int check_flood_line(Image* image, int y, int left, int right,
const gfx::Rect& bounds,
int src_color, int tolerance, void *data, AlgoHLine proc)
{
int c;
FLOODED_LINE *p;
int ret = false;
while (left <= right) {
c = y;
for (;;) {
p = FLOOD_LINE(c);
if ((left >= p->lpos) && (left <= p->rpos)) {
left = p->rpos+2;
break;
}
c = p->next;
if (!c) {
left = flooder(image, left, y, bounds, src_color, tolerance, data, proc);
ret = true;
break;
}
}
}
return ret;
}
template<typename ImageTraits>
static void replace_color(Image* image, const gfx::Rect& bounds, int src_color, int tolerance, void *data, AlgoHLine proc)
{
typename ImageTraits::address_t address;
for (int y=bounds.y; y<bounds.y2(); ++y) {
address = reinterpret_cast<typename ImageTraits::address_t>(image->getPixelAddress(bounds.x, y));
for (int x=bounds.x; x<bounds.x2(); ++x, ++address) {
int right = -1;
if (color_equal<ImageTraits>((int)(*address), src_color, tolerance)) {
++address;
for (right=x+1; right<bounds.x2(); ++right, ++address) {
if (!color_equal<ImageTraits>((int)(*address), src_color, tolerance))
break;
}
(*proc)(x, y, right-1, data);
x = right;
}
}
}
}
/* floodfill:
* Fills an enclosed area (starting at point x, y) with the specified color.
*/
void algo_floodfill(Image* image, int x, int y,
const gfx::Rect& bounds,
int tolerance, bool contiguous,
void* data, AlgoHLine proc)
{
// Make sure we have a valid starting point
if ((x < 0) || (x >= image->width()) ||
(y < 0) || (y >= image->height()))
return;
// What color to replace?
color_t src_color = get_pixel(image, x, y);
// Non-contiguous case, we replace colors in the whole image.
if (!contiguous) {
switch (image->pixelFormat()) {
case IMAGE_RGB:
replace_color<RgbTraits>(image, bounds, src_color, tolerance, data, proc);
break;
case IMAGE_GRAYSCALE:
replace_color<GrayscaleTraits>(image, bounds, src_color, tolerance, data, proc);
break;
case IMAGE_INDEXED:
replace_color<IndexedTraits>(image, bounds, src_color, tolerance, data, proc);
break;
}
return;
}
/* set up the list of flooded segments */
flood_buf.resize(image->height());
flood_count = image->height();
FLOODED_LINE* p = (FLOODED_LINE*)&flood_buf[0];
for (int c=0; c<flood_count; c++) {
p[c].flags = 0;
p[c].lpos = SHRT_MAX;
p[c].rpos = SHRT_MIN;
p[c].y = y;
p[c].next = 0;
}
// Start up the flood algorithm
flooder(image, x, y, bounds, src_color, tolerance, data, proc);
// Continue as long as there are some segments still to test
bool done;
do {
done = true;
// For each line on the screen
for (int c=0; c<flood_count; c++) {
p = FLOOD_LINE(c);
// Check below the segment?
if (p->flags & FLOOD_TODO_BELOW) {
p->flags &= ~FLOOD_TODO_BELOW;
if (check_flood_line(image, p->y+1, p->lpos, p->rpos, bounds,
src_color, tolerance, data, proc)) {
done = false;
p = FLOOD_LINE(c);
}
}
// Check above the segment?
if (p->flags & FLOOD_TODO_ABOVE) {
p->flags &= ~FLOOD_TODO_ABOVE;
if (check_flood_line(image, p->y-1, p->lpos, p->rpos, bounds,
src_color, tolerance, data, proc)) {
done = false;
// Special case shortcut for going backwards
if ((c > bounds.y) && (c < bounds.y2()))
c -= 2;
}
}
}
} while (!done);
}
} // namespace raster