ref: b0e4642366a76e49553afa9947715ba0cc0c07a6
dir: /src/ztriangle.c/
#include "../include/zbuffer.h"
#include "msghandling.h"
#include <stdlib.h>
#if TGL_FEATURE_RENDER_BITS == 32
#elif TGL_FEATURE_RENDER_BITS == 16
#else
#error "WRONG MODE!!!"
#endif
#if TGL_FEATURE_POLYGON_STIPPLE
#define THE_X (((GLushort)(pp - pp1)))
#define XSTIP(_a) ((THE_X + _a) & TGL_POLYGON_STIPPLE_MASK_X)
#define YSTIP (the_y & TGL_POLYGON_STIPPLE_MASK_Y)
// NOTES Divide by 8 to get the byte Get the actual bit
#define STIPBIT(_a) (zb->stipplepattern[(XSTIP(_a) | (YSTIP << TGL_POLYGON_STIPPLE_POW2_WIDTH)) >> 3] & (1 << (XSTIP(_a) & 7)))
#define STIPTEST(_a) !(zb->dostipple && !STIPBIT(_a))
#else
#define STIPTEST(_a) (1)
//#define ZCMP(z,zpix,_a) ((z) >= (zpix))
#endif
#if TGL_FEATURE_NO_DRAW_COLOR == 1
#define NODRAWTEST(c) ((c & TGL_COLOR_MASK) != TGL_NO_DRAW_COLOR)
#else
#define NODRAWTEST(c) (1)
#endif
#define ZCMP(z, zpix, _a, c) ((z) >= (zpix) && STIPTEST(_a) && NODRAWTEST(c))
void ZB_fillTriangleFlat(ZBuffer* zb, ZBufferPoint* p0, ZBufferPoint* p1, ZBufferPoint* p2) {
PIXEL color;
#define INTERP_Z
#define DRAW_INIT() \
{ color = RGB_TO_PIXEL(p2->r, p2->g, p2->b); }
#define PUT_PIXEL(_a) \
{ \
zz = z >> ZB_POINT_Z_FRAC_BITS; \
if (ZCMP(zz, pz[_a], _a, color)) { \
pp[_a] = color; \
pz[_a] = zz; \
} \
z += dzdx; \
}
#include "ztriangle.h"
}
/*
* Smooth filled triangle.
* The code below is very tricky :)
*/
void ZB_fillTriangleSmooth(ZBuffer* zb, ZBufferPoint* p0, ZBufferPoint* p1, ZBufferPoint* p2) {
#if TGL_FEATURE_NO_DRAW_COLOR == 1
PIXEL c;
#endif
// GLuint color;
#define INTERP_Z
#define INTERP_RGB
#define SAR_RND_TO_ZERO(v, n) (v / (1 << n))
#if TGL_FEATURE_RENDER_BITS == 32
#define DRAW_INIT() \
{}
#if TGL_FEATURE_NO_DRAW_COLOR != 1
#define PUT_PIXEL(_a) \
{ \
zz = z >> ZB_POINT_Z_FRAC_BITS; \
if (ZCMP(zz, pz[_a], _a, RGB_TO_PIXEL(or1, og1, ob1))) { \
pp[_a] = RGB_TO_PIXEL(or1, og1, ob1); \
pz[_a] = zz; \
} \
z += dzdx; \
og1 += dgdx; \
or1 += drdx; \
ob1 += dbdx; \
}
#else
#define PUT_PIXEL(_a) \
{ \
zz = z >> ZB_POINT_Z_FRAC_BITS; \
c = RGB_TO_PIXEL(or1, og1, ob1); \
if (ZCMP(zz, pz[_a], _a, c)) { \
pp[_a] = c; \
pz[_a] = zz; \
} \
z += dzdx; \
og1 += dgdx; \
or1 += drdx; \
ob1 += dbdx; \
}
#endif
// END OF 32 bit mode
#elif TGL_FEATURE_RENDER_BITS == 16
#define DRAW_INIT() \
{}
/*
#define PUT_PIXEL(_a) \
{ \
zz=z >> ZB_POINT_Z_FRAC_BITS; \
if (ZCMP(zz,pz[_a],_a)) { \
pp[_a] = RGB_TO_PIXEL(or1, og1, ob1);\
pz[_a]=zz; \
}\
z+=dzdx; \
og1+=dgdx; \
or1+=drdx; \
ob1+=dbdx; \
}
*/
#if TGL_FEATURE_NO_DRAW_COLOR != 1
#define PUT_PIXEL(_a) \
{ \
zz = z >> ZB_POINT_Z_FRAC_BITS; \
if (ZCMP(zz, pz[_a], _a, 0)) { \
pp[_a] = RGB_TO_PIXEL(or1, og1, ob1); \
pz[_a] = zz; \
} \
z += dzdx; \
og1 += dgdx; \
or1 += drdx; \
ob1 += dbdx; \
}
#else
#define PUT_PIXEL(_a) \
{ \
zz = z >> ZB_POINT_Z_FRAC_BITS; \
c = RGB_TO_PIXEL(or1, og1, ob1); \
if (ZCMP(zz, pz[_a], _a, c)) { \
pp[_a] = c; \
pz[_a] = zz; \
} \
z += dzdx; \
og1 += dgdx; \
or1 += drdx; \
ob1 += dbdx; \
}
#endif
#endif
//^ End of 16 bit mode stuff
#include "ztriangle.h"
} // EOF smooth fill triangle
//
//
// TEXTURE MAPPED TRIANGLES
// Section_Header
//
//
//
//
void ZB_setTexture(ZBuffer* zb, PIXEL* texture) { zb->current_texture = texture; }
// Ignore this it is never used
/*
void ZB_fillTriangleMapping(ZBuffer* zb, ZBufferPoint* p0, ZBufferPoint* p1, ZBufferPoint* p2) {
PIXEL* texture;
//#if TGL_FEATURE_NO_DRAW_COLOR == 1
PIXEL c;
//#endif
//#define INTERP_Z
//#define INTERP_ST
//#define INTERP_RGB
//#define DRAW_INIT() \ { texture = zb->current_texture; }
//#if TGL_FEATURE_NO_DRAW_COLOR != 1
//#define PUT_PIXEL(_a) \
{ \
zz = z >> ZB_POINT_Z_FRAC_BITS; \
if (ZCMP(zz, pz[_a], _a, 0)) { \
pp[_a] = texture[((t & 0x3FC00000) | s) >> 14]; \
pz[_a] = zz; \
} \
z += dzdx; \
s += dsdx; \
t += dtdx; \
}
//#else
//#define PUT_PIXEL(_a) \
{ \
zz = z >> ZB_POINT_Z_FRAC_BITS; \
c = texture[((t & 0x3FC00000) | s) >> 14]; \
if (ZCMP(zz, pz[_a], _a, c)) { \
pp[_a] = c; \
pz[_a] = zz; \
} \
z += dzdx; \
s += dsdx; \
t += dtdx; \
}
//#endif
//#include "ztriangle.h"
}
*/
/*
* Texture mapping with perspective correction.
* We use the gradient method to make less divisions.
* TODO: pipeline the division
*/
#if 1 // IF 1
void ZB_fillTriangleMappingPerspective(ZBuffer* zb, ZBufferPoint* p0, ZBufferPoint* p1, ZBufferPoint* p2) {
PIXEL* texture;
GLfloat fdzdx, fndzdx, ndszdx, ndtzdx;
#if TGL_FEATURE_NO_DRAW_COLOR == 1
PIXEL c;
#endif
#define INTERP_Z
#define INTERP_STZ
#define INTERP_RGB
#define NB_INTERP 8
#define DRAW_INIT() \
{ \
texture = zb->current_texture; \
fdzdx = (GLfloat)dzdx; \
fndzdx = NB_INTERP * fdzdx; \
ndszdx = NB_INTERP * dszdx; \
ndtzdx = NB_INTERP * dtzdx; \
}
#if TGL_FEATURE_LIT_TEXTURES == 1
#define OR1OG1OB1DECL register GLuint or1, og1, ob1;or1=r1;og1=g1;ob1=b1;
#define OR1G1B1INCR og1 += dgdx;or1 += drdx;ob1 += dbdx;
#else
#define OR1OG1OB1DECL /*A comment*/
#define OR1G1B1INCR /*Another comment*/
#define or1 0xffff
#define og1 0xffff
#define ob1 0xffff
#endif
#if TGL_FEATURE_NO_DRAW_COLOR != 1
#define PUT_PIXEL(_a) \
{ \
zz = z >> ZB_POINT_Z_FRAC_BITS; \
if (ZCMP(zz, pz[_a], _a, 0)) { \
pp[_a] = RGB_MIX_FUNC(or1,og1,ob1, *(PIXEL*)((GLbyte*)texture + (((t & 0x3FC00000) | (s & 0x003FC000)) >> (17 - PSZSH)))); \
pz[_a] = zz; \
} \
z += dzdx; \
s += dsdx; \
t += dtdx; \
OR1G1B1INCR \
}
#else
#define PUT_PIXEL(_a) \
{ \
zz = z >> ZB_POINT_Z_FRAC_BITS; \
c = *(PIXEL*)((GLbyte*)texture + (((t & 0x3FC00000) | (s & 0x003FC000)) >> (17 - PSZSH))); \
if (ZCMP(zz, pz[_a], _a, c)) { \
pp[_a] = RGB_MIX_FUNC(or1,og1,ob1,c); \
pz[_a] = zz; \
} \
z += dzdx; \
s += dsdx; \
t += dtdx; \
OR1G1B1INCR \
}
#endif
#define DRAW_LINE() \
{ \
register GLushort* pz; \
register PIXEL* pp; \
register GLuint s, t, z, zz; \
register GLint n, dsdx, dtdx; \
OR1OG1OB1DECL \
GLfloat sz, tz, fz, zinv; \
n = (x2 >> 16) - x1; \
fz = (GLfloat)z1; \
zinv = 1.0 / fz; \
pp = (PIXEL*)((GLbyte*)pp1 + x1 * PSZB); \
pz = pz1 + x1; \
z = z1; \
sz = sz1; \
tz = tz1; \
while (n >= (NB_INTERP - 1)) { \
{ \
GLfloat ss, tt; \
ss = (sz * zinv); \
tt = (tz * zinv); \
s = (GLint)ss; \
t = (GLint)tt; \
dsdx = (GLint)((dszdx - ss * fdzdx) * zinv); \
dtdx = (GLint)((dtzdx - tt * fdzdx) * zinv); \
fz += fndzdx; \
zinv = 1.0 / fz; \
} \
PUT_PIXEL(0); /*the_x++;*/ \
PUT_PIXEL(1); /*the_x++;*/ \
PUT_PIXEL(2); /*the_x++;*/ \
PUT_PIXEL(3); /*the_x++;*/ \
PUT_PIXEL(4); /*the_x++;*/ \
PUT_PIXEL(5); /*the_x++;*/ \
PUT_PIXEL(6); /*the_x++;*/ \
PUT_PIXEL(7); /*the_x-=7;*/ \
pz += NB_INTERP; \
pp = (PIXEL*)((GLbyte*)pp + NB_INTERP * PSZB); /*the_x+=NB_INTERP * PSZB;*/ \
n -= NB_INTERP; \
sz += ndszdx; \
tz += ndtzdx; \
} \
{ \
GLfloat ss, tt; \
ss = (sz * zinv); \
tt = (tz * zinv); \
s = (GLint)ss; \
t = (GLint)tt; \
dsdx = (GLint)((dszdx - ss * fdzdx) * zinv); \
dtdx = (GLint)((dtzdx - tt * fdzdx) * zinv); \
} \
while (n >= 0) { \
PUT_PIXEL(0); /*the_x += PSZB;*/ \
pz += 1; \
pp = (PIXEL*)((GLbyte*)pp + PSZB); \
n -= 1; \
} \
}
#include "ztriangle.h"
}
#endif // if 1
#if 0
/* slow but exact version (only there for reference, incorrect for 24
bits) */
void ZB_fillTriangleMappingPerspective(ZBuffer *zb,
ZBufferPoint *p0,ZBufferPoint *p1,ZBufferPoint *p2)
{
PIXEL *texture;
#define INTERP_Z
#define INTERP_STZ
#define DRAW_INIT() \
{ texture = zb->current_texture; }
#define PUT_PIXEL(_a) \
{ \
GLfloat zinv; \
GLint s, t; \
zz = z >> ZB_POINT_Z_FRAC_BITS; \
if (ZCMP(zz, pz[_a], _a)) { \
zinv = 1.0 / (GLfloat)z; \
s = (GLint)(sz * zinv); \
t = (GLint)(tz * zinv); \
pp[_a] = texture[((t & 0x3FC00000) | s) >> 14]; \
pz[_a] = zz; \
} \
z += dzdx; \
sz += dszdx; \
tz += dtzdx; \
}
#include "ztriangle.h"
}
#endif