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#define __NR_PIXBLOCK_LINE_C__
/*
* Pixel buffer rendering library
*
* Authors:
* Lauris Kaplinski <lauris@kaplinski.com>
*
* This code is in public domain
*/
#include <libnr/nr-pixops.h>
#include <libnr/nr-pixblock-pixel.h>
void
nr_pixblock_draw_line_rgba32 (NRPixBlock *d, long x0, long y0, long x1, long y1, short /*first*/, unsigned long rgba)
{
long deltax, deltay, xinc1, xinc2, yinc1, yinc2;
long den, num, numadd, numpixels;
long x, y, curpixel;
/* Pixblock */
int dbpp;
NRPixBlock spb;
unsigned char *spx;
if (x1 >= x0) {
deltax = x1 - x0;
xinc1 = 1;
xinc2 = 1;
} else {
deltax = x0 - x1;
xinc1 = -1;
xinc2 = -1;
}
if (y1 >= y0) {
deltay = y1 - y0;
yinc1 = 1;
yinc2 = 1;
} else {
deltay = y0 - y1;
yinc1 = -1;
yinc2 = -1;
}
if (deltax >= deltay) {
xinc1 = 0;
yinc2 = 0;
den = deltax;
num = deltax / 2;
numadd = deltay;
numpixels = deltax;
} else {
xinc2 = 0;
yinc1 = 0;
den = deltay;
num = deltay / 2;
numadd = deltax;
numpixels = deltay;
}
/* We can be quite sure 1x1 pixblock is TINY */
nr_pixblock_setup_fast (&spb, NR_PIXBLOCK_MODE_R8G8B8A8N, 0, 0, 1, 1, 0);
spb.empty = 0;
spx = NR_PIXBLOCK_PX (&spb);
spx[0] = NR_RGBA32_R (rgba);
spx[1] = NR_RGBA32_G (rgba);
spx[2] = NR_RGBA32_B (rgba);
spx[3] = NR_RGBA32_A (rgba);
dbpp = NR_PIXBLOCK_BPP (d);
x = x0;
y = y0;
for (curpixel = 0; curpixel <= numpixels; curpixel++) {
if ((x >= d->area.x0) && (y >= d->area.y0) && (x < d->area.x1) && (y < d->area.y1)) {
nr_compose_pixblock_pixblock_pixel (d, NR_PIXBLOCK_PX (d) + (y - d->area.y0) * d->rs + (x - d->area.x0) * dbpp, &spb, spx);
}
num += numadd;
if (num >= den) {
num -= den;
x += xinc1;
y += yinc1;
}
x += xinc2;
y += yinc2;
}
nr_pixblock_release (&spb);
}
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