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/*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
* All rights reserved.
*
* The Original Code is: some of this file.
*
* ***** END GPL LICENSE BLOCK *****
* */
/** \file blender/blenlib/intern/bitmap_draw_2d.c
* \ingroup bli
*
* Utility functions for primitive drawing operations.
*/
#include "MEM_guardedalloc.h"
#include "BLI_bitmap_draw_2d.h"
#include "BLI_utildefines.h"
#include "BLI_strict_flags.h"
/**
* Plot a line from \a p1 to \a p2 (inclusive).
*/
void plot_line_v2v2i(
const int p1[2], const int p2[2],
bool (*callback)(int, int, void *), void *userData)
{
/* Bresenham's line algorithm. */
int x1 = p1[0];
int y1 = p1[1];
int x2 = p2[0];
int y2 = p2[1];
int ix;
int iy;
/* if x1 == x2 or y1 == y2, then it does not matter what we set here */
int delta_x = (x2 > x1 ? ((void)(ix = 1), x2 - x1) : ((void)(ix = -1), x1 - x2)) << 1;
int delta_y = (y2 > y1 ? ((void)(iy = 1), y2 - y1) : ((void)(iy = -1), y1 - y2)) << 1;
if (callback(x1, y1, userData) == 0) {
return;
}
if (delta_x >= delta_y) {
/* error may go below zero */
int error = delta_y - (delta_x >> 1);
while (x1 != x2) {
if (error >= 0) {
if (error || (ix > 0)) {
y1 += iy;
error -= delta_x;
}
/* else do nothing */
}
/* else do nothing */
x1 += ix;
error += delta_y;
if (callback(x1, y1, userData) == 0) {
return;
}
}
}
else {
/* error may go below zero */
int error = delta_x - (delta_y >> 1);
while (y1 != y2) {
if (error >= 0) {
if (error || (iy > 0)) {
x1 += ix;
error -= delta_y;
}
/* else do nothing */
}
/* else do nothing */
y1 += iy;
error += delta_x;
if (callback(x1, y1, userData) == 0) {
return;
}
}
}
}
/**
* \param callback: Takes the x, y coords and x-span (\a x_end is not inclusive),
* note that \a x_end will always be greater than \a x, so we can use:
*
* \code{.c}
* do {
* func(x, y);
* } while (++x != x_end);
* \endcode
*/
void fill_poly_v2i_n(
const int xmin, const int ymin, const int xmax, const int ymax,
const int verts[][2], const int nr,
void (*callback)(int x, int x_end, int y, void *), void *userData)
{
/* Originally by Darel Rex Finley, 2007.
*/
int nodes, pixel_y, i, j, swap;
int *node_x = MEM_mallocN(sizeof(*node_x) * (size_t)(nr + 1), __func__);
/* Loop through the rows of the image. */
for (pixel_y = ymin; pixel_y < ymax; pixel_y++) {
/* Build a list of nodes. */
nodes = 0; j = nr - 1;
for (i = 0; i < nr; i++) {
if ((verts[i][1] < pixel_y && verts[j][1] >= pixel_y) ||
(verts[j][1] < pixel_y && verts[i][1] >= pixel_y))
{
node_x[nodes++] = (int)(verts[i][0] +
((double)(pixel_y - verts[i][1]) / (verts[j][1] - verts[i][1])) *
(verts[j][0] - verts[i][0]));
}
j = i;
}
/* Sort the nodes, via a simple "Bubble" sort. */
i = 0;
while (i < nodes - 1) {
if (node_x[i] > node_x[i + 1]) {
SWAP_TVAL(swap, node_x[i], node_x[i + 1]);
if (i) i--;
}
else {
i++;
}
}
/* Fill the pixels between node pairs. */
for (i = 0; i < nodes; i += 2) {
if (node_x[i] >= xmax) break;
if (node_x[i + 1] > xmin) {
if (node_x[i ] < xmin) node_x[i ] = xmin;
if (node_x[i + 1] > xmax) node_x[i + 1] = xmax;
#if 0
/* for many x/y calls */
for (j = node_x[i]; j < node_x[i + 1]; j++) {
callback(j - xmin, pixel_y - ymin, userData);
}
#else
/* for single call per x-span */
if (node_x[i] < node_x[i + 1]) {
callback(node_x[i] - xmin, node_x[i + 1] - xmin, pixel_y - ymin, userData);
}
#endif
}
}
}
MEM_freeN(node_x);
}
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