1 #define __NR_PIXBLOCK_LINE_C__
3 /*
4 * Pixel buffer rendering library
5 *
6 * Authors:
7 * Lauris Kaplinski <lauris@kaplinski.com>
8 *
9 * This code is in public domain
10 */
12 #include <libnr/nr-pixops.h>
13 #include <libnr/nr-pixblock-pixel.h>
15 void
16 nr_pixblock_draw_line_rgba32 (NRPixBlock *d, long x0, long y0, long x1, long y1, short first, unsigned long rgba)
17 {
18 long deltax, deltay, xinc1, xinc2, yinc1, yinc2;
19 long den, num, numadd, numpixels;
20 long x, y, curpixel;
21 /* Pixblock */
22 int dbpp;
23 NRPixBlock spb;
24 unsigned char *spx;
26 if (x1 >= x0) {
27 deltax = x1 - x0;
28 xinc1 = 1;
29 xinc2 = 1;
30 } else {
31 deltax = x0 - x1;
32 xinc1 = -1;
33 xinc2 = -1;
34 }
36 if (y1 >= y0) {
37 deltay = y1 - y0;
38 yinc1 = 1;
39 yinc2 = 1;
40 } else {
41 deltay = y0 - y1;
42 yinc1 = -1;
43 yinc2 = -1;
44 }
46 if (deltax >= deltay) {
47 xinc1 = 0;
48 yinc2 = 0;
49 den = deltax;
50 num = deltax / 2;
51 numadd = deltay;
52 numpixels = deltax;
53 } else {
54 xinc2 = 0;
55 yinc1 = 0;
56 den = deltay;
57 num = deltay / 2;
58 numadd = deltax;
59 numpixels = deltay;
60 }
62 /* We can be quite sure 1x1 pixblock is TINY */
63 nr_pixblock_setup_fast (&spb, NR_PIXBLOCK_MODE_R8G8B8A8N, 0, 0, 1, 1, 0);
64 spb.empty = 0;
65 spx = NR_PIXBLOCK_PX (&spb);
66 spx[0] = NR_RGBA32_R (rgba);
67 spx[1] = NR_RGBA32_G (rgba);
68 spx[2] = NR_RGBA32_B (rgba);
69 spx[3] = NR_RGBA32_A (rgba);
71 dbpp = NR_PIXBLOCK_BPP (d);
73 x = x0;
74 y = y0;
76 for (curpixel = 0; curpixel <= numpixels; curpixel++) {
77 if ((x >= d->area.x0) && (y >= d->area.y0) && (x < d->area.x1) && (y < d->area.y1)) {
78 nr_compose_pixblock_pixblock_pixel (d, NR_PIXBLOCK_PX (d) + (y - d->area.y0) * d->rs + (x - d->area.x0) * dbpp, &spb, spx);
79 }
80 num += numadd;
81 if (num >= den) {
82 num -= den;
83 x += xinc1;
84 y += yinc1;
85 }
86 x += xinc2;
87 y += yinc2;
88 }
90 nr_pixblock_release (&spb);
91 }