/* $Id: t_vb_cliptmp.h,v 1.10 2001/03/19 02:25:37 keithw Exp $ */
/*
* Mesa 3-D graphics library
* Version: 3.5
*
* Copyright (C) 1999-2001 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* Authors:
* Keith Whitwell <keithw@valinux.com>
*/
#define CLIP_DOTPROD(K, A, B, C, D) X(K)*A + Y(K)*B + Z(K)*C + W(K)*D
#define POLY_CLIP( PLANE, A, B, C, D ) \
do { \
if (mask & PLANE) { \
GLuint idxPrev = inlist[0]; \
GLfloat dpPrev = CLIP_DOTPROD(idxPrev, A, B, C, D ); \
GLuint outcount = 0; \
GLuint i; \
\
inlist[n] = inlist[0]; /* prevent rotation of vertices */ \
for (i = 1; i <= n; i++) { \
GLuint idx = inlist[i]; \
GLfloat dp = CLIP_DOTPROD(idx, A, B, C, D ); \
\
clipmask[idxPrev] |= PLANE; \
if (!NEGATIVE(dpPrev)) { \
outlist[outcount++] = idxPrev; \
clipmask[idxPrev] &= ~PLANE; \
} \
\
if (DIFFERENT_SIGNS(dp, dpPrev)) { \
GLuint newvert = VB->LastClipped++; \
VB->ClipMask[newvert] = 0; \
outlist[outcount++] = newvert; \
if (NEGATIVE(dp)) { \
/* Going out of bounds. Avoid division by zero as we \
* know dp != dpPrev from DIFFERENT_SIGNS, above. \
*/ \
GLfloat t = dp / (dp - dpPrev); \
LINTERP_4F( t, coord, newvert, idx, idxPrev, SIZE ); \
interp( ctx, t, newvert, idx, idxPrev, GL_TRUE ); \
} else { \
/* Coming back in. \
*/ \
GLfloat t = dpPrev / (dpPrev - dp); \
LINTERP_4F( t, coord, newvert, idxPrev, idx, SIZE ); \
interp( ctx, t, newvert, idxPrev, idx, GL_FALSE ); \
} \
} \
\
idxPrev = idx; \
dpPrev = dp; \
} \
\
if (outcount < 3) \
return; \
\
{ \
GLuint *tmp = inlist; \
inlist = outlist; \
outlist = tmp; \
n = outcount; \
} \
} \
} while (0)
#define LINE_CLIP(PLANE, A, B, C, D ) \
do { \
if (mask & PLANE) { \
GLfloat dpI = CLIP_DOTPROD( ii, A, B, C, D ); \
GLfloat dpJ = CLIP_DOTPROD( jj, A, B, C, D ); \
\
if (DIFFERENT_SIGNS(dpI, dpJ)) { \
GLuint newvert = VB->LastClipped++; \
VB->ClipMask[newvert] = 0; \
if (NEGATIVE(dpJ)) { \
GLfloat t = dpI / (dpI - dpJ); \
VB->ClipMask[jj] |= PLANE; \
LINTERP_4F( t, coord, newvert, ii, jj, SIZE ); \
interp( ctx, t, newvert, ii, jj, GL_FALSE ); \
jj = newvert; \
} else { \
GLfloat t = dpJ / (dpJ - dpI); \
VB->ClipMask[ii] |= PLANE; \
LINTERP_4F( t, coord, newvert, jj, ii, SIZE ); \
interp( ctx, t, newvert, jj, ii, GL_FALSE ); \
ii = newvert; \
} \
} \
else if (NEGATIVE(dpI)) \
return; \
} \
} while (0)
/* Clip a line against the viewport and user clip planes.
*/
static __inline void TAG(clip_line)( GLcontext *ctx,
GLuint i, GLuint j,
GLubyte mask )
{
TNLcontext *tnl = TNL_CONTEXT(ctx);
struct vertex_buffer *VB = &tnl->vb;
interp_func interp = tnl->Driver.RenderInterp;
GLfloat (*coord)[4] = VB->ClipPtr->data;
GLuint ii = i, jj = j, p;
VB->LastClipped = VB->FirstClipped;
if (mask & 0x3f) {
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 (mask & CLIP_USER_BIT) {
for (p=0;p<MAX_CLIP_PLANES;p++) {
if (ctx->Transform.ClipEnabled[p]) {
GLfloat a = ctx->Transform._ClipUserPlane[p][0];
GLfloat b = ctx->Transform._ClipUserPlane[p][1];
GLfloat c = ctx->Transform._ClipUserPlane[p][2];
GLfloat d = ctx->Transform._ClipUserPlane[p][3];
LINE_CLIP( CLIP_USER_BIT, a, b, c, d );
}
}
}
if ((ctx->_TriangleCaps & DD_FLATSHADE) && j != jj)
tnl->Driver.RenderCopyPV( ctx, jj, j );
tnl->Driver.RenderClippedLine( ctx, ii, jj );
}
/* Clip a triangle against the viewport and user clip planes.
*/
static __inline void TAG(clip_tri)( GLcontext *ctx,
GLuint v0, GLuint v1, GLuint v2,
GLubyte mask )
{
TNLcontext *tnl = TNL_CONTEXT(ctx);
struct vertex_buffer *VB = &tnl->vb;
interp_func interp = tnl->Driver.RenderInterp;
GLfloat (*coord)[4] = VB->ClipPtr->data;
GLuint pv = v0;
GLuint vlist[2][MAX_CLIPPED_VERTICES];
GLuint *inlist = vlist[0], *outlist = vlist[1];
GLuint p;
GLubyte *clipmask = VB->ClipMask;
GLuint n = 3;
ASSIGN_3V(inlist, v0, v1, v2 );
VB->LastClipped = VB->FirstClipped;
if (mask & 0x3f) {
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 (mask & CLIP_USER_BIT) {
for (p=0;p<MAX_CLIP_PLANES;p++) {
if (ctx->Transform.ClipEnabled[p]) {
GLfloat a = ctx->Transform._ClipUserPlane[p][0];
GLfloat b = ctx->Transform._ClipUserPlane[p][1];
GLfloat c = ctx->Transform._ClipUserPlane[p][2];
GLfloat d = ctx->Transform._ClipUserPlane[p][3];
POLY_CLIP( CLIP_USER_BIT, a, b, c, d );
}
}
}
if (ctx->_TriangleCaps & DD_FLATSHADE) {
if (pv != inlist[0]) {
ASSERT( inlist[0] >= VB->FirstClipped );
tnl->Driver.RenderCopyPV( ctx, inlist[0], pv );
}
}
tnl->Driver.RenderClippedPolygon( ctx, inlist, n );
}
/* Clip a quad against the viewport and user clip planes.
*/
static __inline void TAG(clip_quad)( GLcontext *ctx,
GLuint v0, GLuint v1, GLuint v2, GLuint v3,
GLubyte mask )
{
TNLcontext *tnl = TNL_CONTEXT(ctx);
struct vertex_buffer *VB = &tnl->vb;
interp_func interp = tnl->Driver.RenderInterp;
GLfloat (*coord)[4] = VB->ClipPtr->data;
GLuint pv = v0;
GLuint vlist[2][MAX_CLIPPED_VERTICES];
GLuint *inlist = vlist[0], *outlist = vlist[1];
GLuint p;
GLubyte *clipmask = VB->ClipMask;
GLuint n = 4;
ASSIGN_4V(inlist, v0, v1, v2, v3 );
VB->LastClipped = VB->FirstClipped;
if (mask & 0x3f) {
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 (mask & CLIP_USER_BIT) {
for (p=0;p<MAX_CLIP_PLANES;p++) {
if (ctx->Transform.ClipEnabled[p]) {
GLfloat a = ctx->Transform._ClipUserPlane[p][0];
GLfloat b = ctx->Transform._ClipUserPlane[p][1];
GLfloat c = ctx->Transform._ClipUserPlane[p][2];
GLfloat d = ctx->Transform._ClipUserPlane[p][3];
POLY_CLIP( CLIP_USER_BIT, a, b, c, d );
}
}
}
if (ctx->_TriangleCaps & DD_FLATSHADE) {
if (pv != inlist[0]) {
ASSERT( inlist[0] >= VB->FirstClipped );
tnl->Driver.RenderCopyPV( ctx, inlist[0], pv );
}
}
tnl->Driver.RenderClippedPolygon( ctx, inlist, n );
}
#undef W
#undef Z
#undef Y
#undef X
#undef SIZE
#undef TAG
#undef POLY_CLIP
#undef LINE_CLIP