#define CLIP_DOTPROD(K, A, B, C, D) \
(CLIP_X(K)*A + CLIP_Y(K)*B + \
CLIP_Z(K)*C + CLIP_W(K)*D)
#define POLY_CLIP( PLANE, A, B, C, D ) \
do { \
if (mask & PLANE) { \
TNL_VERTEX **indata = inlist[in]; \
TNL_VERTEX **outdata = inlist[in ^= 1]; \
TNL_VERTEX *J = indata[0]; \
GLfloat dpJ = CLIP_DOTPROD(J, A, B, C, D ); \
GLuint outcount = 0; \
GLuint i; \
\
indata[n] = indata[0]; \
for (i = 1; i <= n; i++) { \
TNL_VERTEX *I = indata[i]; \
GLfloat dpI = CLIP_DOTPROD(idx, A, B, C, D ); \
\
if (!NEGATIVE(dpPrev)) { \
outdata[outcount++] = J; \
} \
\
if (DIFFERENT_SIGNS(dpI, dpJ)) { \
TNL_VERTEX *O = verts++; \
outdata[outcount++] = O; \
if (NEGATIVE(dpI)) { \
\
GLfloat t = dpI / (dpI - dpJ); \
INTERP( ctx, t, O, I, J ); \
} else { \
\
GLfloat t = dpJ / (dpJ - dpI); \
INTERP( ctx, t, O, J, I ); \
} \
} \
\
J = I; \
dpJ = dpI; \
} \
\
if (outcount < 3) \
return; \
\
nr = outcount; \
} \
} while (0)
#define LINE_CLIP(PLANE, A, B, C, D ) \
do { \
if (mask & PLANE) { \
GLfloat dpI = CLIP_DOTPROD( I, A, B, C, D ); \
GLfloat dpJ = CLIP_DOTPROD( J, A, B, C, D ); \
\
if (DIFFERENT_SIGNS(dpI, dpJ)) { \
TNL_VERTEX *O = verts++; \
if (NEGATIVE(dpJ)) { \
GLfloat t = dpI / (dpI - dpJ); \
INTERP( ctx, t, O, I, J ); \
J = O; \
} else { \
GLfloat t = dpJ / (dpJ - dpI); \
INTERP( ctx, t, O, J, I ); \
I = O; \
} \
} \
else if (NEGATIVE(dpI)) \
return; \
} \
} while (0)
static void TAG(clip_draw_line)( GLcontext *ctx,
TNL_VERTEX *I,
TNL_VERTEX *J,
GLuint mask )
{
LOCAL_VARS;
GET_INTERP_FUNC;
TNL_VERTEX tmp[MAX_CLIPPED_VERTICES];
TNL_VERTEX *verts = tmp;
TNL_VERTEX *pv = J;
LINE_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 );
LINE_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 );
LINE_CLIP( CLIP_TOP_BIT, 0, -1, 0, 1 );
LINE_CLIP( CLIP_BOTTOM_BIT, 0, 1, 0, 1 );
LINE_CLIP( CLIP_FAR_BIT, 0, 0, -1, 1 );
LINE_CLIP( CLIP_NEAR_BIT, 0, 0, 1, 1 );
if ((ctx->_TriangleCaps & DD_FLATSHADE) && J != pv)
COPY_PV( ctx, J, pv );
DRAW_LINE( I, J );
}
static void TAG(clip_draw_triangle)( GLcontext *ctx,
TNL_VERTEX *v0,
TNL_VERTEX *v1,
TNL_VERTEX *v2,
GLuint mask )
{
LOCAL_VARS;
GET_INTERP_FUNC;
TNL_VERTEX tmp[MAX_CLIPPED_VERTICES];
TNL_VERTEX *verts = tmp;
TNL_VERTEX *(inlist[2][MAX_CLIPPED_VERTICES]);
TNL_VERTEX **out;
GLuint in = 0;
GLuint n = 3;
GLuint i;
ASSIGN_3V(inlist, v2, v0, v1 );
POLY_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 );
POLY_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 );
POLY_CLIP( CLIP_TOP_BIT, 0, -1, 0, 1 );
POLY_CLIP( CLIP_BOTTOM_BIT, 0, 1, 0, 1 );
POLY_CLIP( CLIP_FAR_BIT, 0, 0, -1, 1 );
POLY_CLIP( CLIP_NEAR_BIT, 0, 0, 1, 1 );
if ((ctx->_TriangleCaps & DD_FLATSHADE) && v2 != inlist[0])
COPY_PV( ctx, inlist[0], v2 );
out = inlist[in];
DRAW_POLYGON( out, n );
}
static __inline void TAG(draw_triangle)( GLcontext *ctx,
TNL_VERTEX *v0,
TNL_VERTEX *v1,
TNL_VERTEX *v2 )
{
LOCAL_VARS;
GLubyte ormask = (v0->mask | v1->mask | v2->mask);
if ( !ormask ) {
DRAW_TRI( v0, v1, v2 );
} else if ( !(v0->mask & v1->mask & v2->mask) ) {
TAG(clip_draw_triangle)( ctx, v0, v1, v2, ormask );
}
}
static __inline void TAG(draw_line)( GLcontext *ctx,
TNL_VERTEX *v0,
TNL_VERTEX *v1 )
{
LOCAL_VARS;
GLubyte ormask = (v0->mask | v1->mask);
if ( !ormask ) {
DRAW_LINE( v0, v1 );
} else if ( !(v0->mask & v1->mask) ) {
TAG(clip_draw_line)( ctx, v0, v1, ormask );
}
}