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/*
* Copyright 1998-2003 VIA Technologies, Inc. All Rights Reserved.
* Copyright 2001-2003 S3 Graphics, Inc. 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, sub license,
* 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 (including the
* next paragraph) 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 NON-INFRINGEMENT. IN NO EVENT SHALL
* VIA, S3 GRAPHICS, AND/OR ITS SUPPLIERS 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.
*/
#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); \
INTERP_4F(t, coord[newvert], coord[idx], coord[idxPrev]); \
interp(ctx, t, newvert, idx, idxPrev, GL_TRUE); \
} \
else { \
/* Coming back in. \
*/ \
GLfloat t = dpPrev / (dpPrev - dp); \
INTERP_4F(t, coord[newvert], coord[idxPrev], coord[idx]); \
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; \
INTERP_4F(t, coord[newvert], coord[ii], coord[jj]); \
interp(ctx, t, newvert, ii, jj, GL_FALSE); \
jj = newvert; \
} \
else { \
GLfloat t = dpJ / (dpJ - dpI); \
VB->ClipMask[ii] |= PLANE; \
INTERP_4F(t, coord[newvert], coord[jj], coord[ii]); \
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;
tnl_interp_func interp = tnl->Driver.Render.Interp;
GLfloat (*coord)[4] = VB->ClipPtr->data;
GLuint ii = i, jj = j, p;
#ifdef DEBUG
if (VIA_DEBUG) fprintf(stderr, "%s - in\n", __FUNCTION__);
#endif
#ifdef PERFORMANCE_MEASURE
if (VIA_PERFORMANCE) P_M;
#endif
VB->LastClipped = VB->Count;
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.ClipPlanesEnabled & (1 << 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.Render.CopyPV(ctx, jj, j);
tnl->Driver.Render.ClippedLine(ctx, ii, jj);
#ifdef DEBUG
if (VIA_DEBUG) fprintf(stderr, "%s - out\n", __FUNCTION__);
#endif
}
/* 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;
tnl_interp_func interp = tnl->Driver.Render.Interp;
GLfloat (*coord)[4] = VB->ClipPtr->data;
GLuint pv = v2;
GLuint vlist[2][MAX_CLIPPED_VERTICES];
GLuint *inlist = vlist[0], *outlist = vlist[1];
GLuint p;
GLubyte *clipmask = VB->ClipMask;
GLuint n = 3;
#ifdef PERFORMANCE_MEASURE
if (VIA_PERFORMANCE) P_M;
#endif
ASSIGN_3V(inlist, v2, v0, v1); /* pv rotated to slot zero */
VB->LastClipped = VB->Count;
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.ClipPlanesEnabled & (1 << 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->Count);
tnl->Driver.Render.CopyPV(ctx, inlist[0], pv);
}
}
tnl->Driver.Render.ClippedPolygon(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;
tnl_interp_func interp = tnl->Driver.Render.Interp;
GLfloat (*coord)[4] = VB->ClipPtr->data;
GLuint pv = v3;
GLuint vlist[2][MAX_CLIPPED_VERTICES];
GLuint *inlist = vlist[0], *outlist = vlist[1];
GLuint p;
GLubyte *clipmask = VB->ClipMask;
GLuint n = 4;
#ifdef DEBUG
if (VIA_DEBUG) fprintf(stderr, "%s - in\n", __FUNCTION__);
#endif
#ifdef PERFORMANCE_MEASURE
if (VIA_PERFORMANCE) P_M;
#endif
ASSIGN_4V(inlist, v3, v0, v1, v2); /* pv rotated to slot zero */
VB->LastClipped = VB->Count;
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.ClipPlanesEnabled & (1 << 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->Count);
tnl->Driver.Render.CopyPV(ctx, inlist[0], pv);
}
}
tnl->Driver.Render.ClippedPolygon(ctx, inlist, n);
#ifdef DEBUG
if (VIA_DEBUG) fprintf(stderr, "%s - out\n", __FUNCTION__);
#endif
}
#undef W
#undef Z
#undef Y
#undef X
#undef SIZE
#undef TAG
#undef POLY_CLIP
#undef LINE_CLIP
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