version 2.8
zline.c
1 #include <stdlib.h>
2 #include "zbuffer.h"
3 
4 #define ZCMP(z,zpix) ((z) >= (zpix))
5 
6 void ZB_plot(ZBuffer * zb, ZBufferPoint * p)
7 {
8  unsigned short *pz;
9  PIXEL *pp;
10  int zz;
11 
12  pz = zb->zbuf + (p->y * zb->xsize + p->x);
13  pp = (PIXEL *) ((char *) zb->pbuf + zb->linesize * p->y + p->x * PSZB);
14  zz = p->z >> ZB_POINT_Z_FRAC_BITS;
15  if (ZCMP(zz, *pz)) {
16 #if TGL_FEATURE_RENDER_BITS == 24
17  pp[0]=p->r>>8;
18  pp[1]=p->g>>8;
19  pp[2]=p->b>>8;
20 #else
21  *pp = RGB_TO_PIXEL(p->r, p->g, p->b);
22 #endif
23  *pz = zz;
24  }
25 }
26 
27 #define INTERP_Z
28 static void ZB_line_flat_z(ZBuffer * zb, ZBufferPoint * p1, ZBufferPoint * p2,
29  int color)
30 {
31 #include "zline.h"
32 }
33 
34 /* line with color interpolation */
35 #define INTERP_Z
36 #define INTERP_RGB
37 static void ZB_line_interp_z(ZBuffer * zb, ZBufferPoint * p1, ZBufferPoint * p2)
38 {
39 #include "zline.h"
40 }
41 
42 /* no Z interpolation */
43 
44 static void ZB_line_flat(ZBuffer * zb, ZBufferPoint * p1, ZBufferPoint * p2,
45  int color)
46 {
47 #include "zline.h"
48 }
49 
50 #define INTERP_RGB
51 static void ZB_line_interp(ZBuffer * zb, ZBufferPoint * p1, ZBufferPoint * p2)
52 {
53 #include "zline.h"
54 }
55 
56 void ZB_line_z(ZBuffer * zb, ZBufferPoint * p1, ZBufferPoint * p2)
57 {
58  int color1, color2;
59 
60  color1 = RGB_TO_PIXEL(p1->r, p1->g, p1->b);
61  color2 = RGB_TO_PIXEL(p2->r, p2->g, p2->b);
62 
63  /* choose if the line should have its color interpolated or not */
64  if (color1 == color2) {
65  ZB_line_flat_z(zb, p1, p2, color1);
66  } else {
67  ZB_line_interp_z(zb, p1, p2);
68  }
69 }
70 
71 void ZB_line(ZBuffer * zb, ZBufferPoint * p1, ZBufferPoint * p2)
72 {
73  int color1, color2;
74 
75  color1 = RGB_TO_PIXEL(p1->r, p1->g, p1->b);
76  color2 = RGB_TO_PIXEL(p2->r, p2->g, p2->b);
77 
78  /* choose if the line should have its color interpolated or not */
79  if (color1 == color2) {
80  ZB_line_flat(zb, p1, p2, color1);
81  } else {
82  ZB_line_interp(zb, p1, p2);
83  }
84 }