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| Rev | Author | Line No. | Line |
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| 56 | pj | 1 | /* $Id: t_vb_cliptmp.h,v 1.1 2003-02-28 11:48:07 pj Exp $ */ |
| 2 | |||
| 3 | /* |
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| 4 | * Mesa 3-D graphics library |
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| 5 | * Version: 3.5 |
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| 6 | * |
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| 7 | * Copyright (C) 1999-2001 Brian Paul All Rights Reserved. |
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| 8 | * |
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| 9 | * Permission is hereby granted, free of charge, to any person obtaining a |
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| 10 | * copy of this software and associated documentation files (the "Software"), |
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| 11 | * to deal in the Software without restriction, including without limitation |
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| 12 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
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| 13 | * and/or sell copies of the Software, and to permit persons to whom the |
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| 14 | * Software is furnished to do so, subject to the following conditions: |
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| 15 | * |
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| 16 | * The above copyright notice and this permission notice shall be included |
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| 17 | * in all copies or substantial portions of the Software. |
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| 18 | * |
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| 19 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
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| 20 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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| 21 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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| 22 | * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN |
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| 23 | * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
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| 24 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
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| 25 | * |
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| 26 | * Authors: |
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| 27 | * Keith Whitwell <keith@tungstengraphics.com> |
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| 28 | */ |
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| 29 | |||
| 30 | |||
| 31 | #define CLIP_DOTPROD(K, A, B, C, D) X(K)*A + Y(K)*B + Z(K)*C + W(K)*D |
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| 32 | |||
| 33 | #define POLY_CLIP( PLANE, A, B, C, D ) \ |
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| 34 | do { \ |
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| 35 | if (mask & PLANE) { \ |
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| 36 | GLuint idxPrev = inlist[0]; \ |
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| 37 | GLfloat dpPrev = CLIP_DOTPROD(idxPrev, A, B, C, D ); \ |
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| 38 | GLuint outcount = 0; \ |
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| 39 | GLuint i; \ |
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| 40 | \ |
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| 41 | inlist[n] = inlist[0]; /* prevent rotation of vertices */ \ |
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| 42 | for (i = 1; i <= n; i++) { \ |
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| 43 | GLuint idx = inlist[i]; \ |
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| 44 | GLfloat dp = CLIP_DOTPROD(idx, A, B, C, D ); \ |
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| 45 | \ |
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| 46 | clipmask[idxPrev] |= PLANE; \ |
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| 47 | if (!NEGATIVE(dpPrev)) { \ |
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| 48 | outlist[outcount++] = idxPrev; \ |
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| 49 | clipmask[idxPrev] &= ~PLANE; \ |
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| 50 | } \ |
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| 51 | \ |
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| 52 | if (DIFFERENT_SIGNS(dp, dpPrev)) { \ |
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| 53 | GLuint newvert = VB->LastClipped++; \ |
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| 54 | VB->ClipMask[newvert] = 0; \ |
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| 55 | outlist[outcount++] = newvert; \ |
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| 56 | if (NEGATIVE(dp)) { \ |
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| 57 | /* Going out of bounds. Avoid division by zero as we \ |
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| 58 | * know dp != dpPrev from DIFFERENT_SIGNS, above. \ |
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| 59 | */ \ |
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| 60 | GLfloat t = dp / (dp - dpPrev); \ |
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| 61 | INTERP_4F( t, coord[newvert], coord[idx], coord[idxPrev]); \ |
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| 62 | interp( ctx, t, newvert, idx, idxPrev, GL_TRUE ); \ |
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| 63 | } else { \ |
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| 64 | /* Coming back in. \ |
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| 65 | */ \ |
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| 66 | GLfloat t = dpPrev / (dpPrev - dp); \ |
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| 67 | INTERP_4F( t, coord[newvert], coord[idxPrev], coord[idx]); \ |
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| 68 | interp( ctx, t, newvert, idxPrev, idx, GL_FALSE ); \ |
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| 69 | } \ |
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| 70 | } \ |
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| 71 | \ |
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| 72 | idxPrev = idx; \ |
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| 73 | dpPrev = dp; \ |
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| 74 | } \ |
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| 75 | \ |
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| 76 | if (outcount < 3) \ |
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| 77 | return; \ |
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| 78 | \ |
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| 79 | { \ |
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| 80 | GLuint *tmp = inlist; \ |
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| 81 | inlist = outlist; \ |
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| 82 | outlist = tmp; \ |
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| 83 | n = outcount; \ |
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| 84 | } \ |
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| 85 | } \ |
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| 86 | } while (0) |
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| 87 | |||
| 88 | |||
| 89 | #define LINE_CLIP(PLANE, A, B, C, D ) \ |
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| 90 | do { \ |
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| 91 | if (mask & PLANE) { \ |
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| 92 | GLfloat dpI = CLIP_DOTPROD( ii, A, B, C, D ); \ |
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| 93 | GLfloat dpJ = CLIP_DOTPROD( jj, A, B, C, D ); \ |
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| 94 | \ |
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| 95 | if (DIFFERENT_SIGNS(dpI, dpJ)) { \ |
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| 96 | GLuint newvert = VB->LastClipped++; \ |
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| 97 | VB->ClipMask[newvert] = 0; \ |
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| 98 | if (NEGATIVE(dpJ)) { \ |
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| 99 | GLfloat t = dpI / (dpI - dpJ); \ |
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| 100 | VB->ClipMask[jj] |= PLANE; \ |
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| 101 | INTERP_4F( t, coord[newvert], coord[ii], coord[jj] ); \ |
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| 102 | interp( ctx, t, newvert, ii, jj, GL_FALSE ); \ |
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| 103 | jj = newvert; \ |
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| 104 | } else { \ |
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| 105 | GLfloat t = dpJ / (dpJ - dpI); \ |
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| 106 | VB->ClipMask[ii] |= PLANE; \ |
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| 107 | INTERP_4F( t, coord[newvert], coord[jj], coord[ii] ); \ |
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| 108 | interp( ctx, t, newvert, jj, ii, GL_FALSE ); \ |
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| 109 | ii = newvert; \ |
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| 110 | } \ |
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| 111 | } \ |
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| 112 | else if (NEGATIVE(dpI)) \ |
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| 113 | return; \ |
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| 114 | } \ |
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| 115 | } while (0) |
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| 116 | |||
| 117 | |||
| 118 | |||
| 119 | /* Clip a line against the viewport and user clip planes. |
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| 120 | */ |
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| 121 | static INLINE void |
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| 122 | TAG(clip_line)( GLcontext *ctx, GLuint i, GLuint j, GLubyte mask ) |
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| 123 | { |
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| 124 | TNLcontext *tnl = TNL_CONTEXT(ctx); |
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| 125 | struct vertex_buffer *VB = &tnl->vb; |
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| 126 | interp_func interp = tnl->Driver.Render.Interp; |
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| 127 | GLfloat (*coord)[4] = VB->ClipPtr->data; |
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| 128 | GLuint ii = i, jj = j, p; |
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| 129 | |||
| 130 | VB->LastClipped = VB->FirstClipped; |
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| 131 | |||
| 132 | if (mask & 0x3f) { |
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| 133 | LINE_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 ); |
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| 134 | LINE_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 ); |
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| 135 | LINE_CLIP( CLIP_TOP_BIT, 0, -1, 0, 1 ); |
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| 136 | LINE_CLIP( CLIP_BOTTOM_BIT, 0, 1, 0, 1 ); |
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| 137 | LINE_CLIP( CLIP_FAR_BIT, 0, 0, -1, 1 ); |
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| 138 | LINE_CLIP( CLIP_NEAR_BIT, 0, 0, 1, 1 ); |
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| 139 | } |
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| 140 | |||
| 141 | if (mask & CLIP_USER_BIT) { |
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| 142 | for (p=0;p<MAX_CLIP_PLANES;p++) { |
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| 143 | if (ctx->Transform.ClipPlanesEnabled & (1 << p)) { |
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| 144 | const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; |
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| 145 | const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; |
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| 146 | const GLfloat c = ctx->Transform._ClipUserPlane[p][2]; |
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| 147 | const GLfloat d = ctx->Transform._ClipUserPlane[p][3]; |
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| 148 | LINE_CLIP( CLIP_USER_BIT, a, b, c, d ); |
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| 149 | } |
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| 150 | } |
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| 151 | } |
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| 152 | |||
| 153 | if ((ctx->_TriangleCaps & DD_FLATSHADE) && j != jj) |
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| 154 | tnl->Driver.Render.CopyPV( ctx, jj, j ); |
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| 155 | |||
| 156 | tnl->Driver.Render.ClippedLine( ctx, ii, jj ); |
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| 157 | } |
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| 158 | |||
| 159 | |||
| 160 | /* Clip a triangle against the viewport and user clip planes. |
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| 161 | */ |
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| 162 | static INLINE void |
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| 163 | TAG(clip_tri)( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLubyte mask ) |
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| 164 | { |
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| 165 | TNLcontext *tnl = TNL_CONTEXT(ctx); |
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| 166 | struct vertex_buffer *VB = &tnl->vb; |
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| 167 | interp_func interp = tnl->Driver.Render.Interp; |
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| 168 | GLfloat (*coord)[4] = VB->ClipPtr->data; |
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| 169 | GLuint pv = v2; |
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| 170 | GLuint vlist[2][MAX_CLIPPED_VERTICES]; |
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| 171 | GLuint *inlist = vlist[0], *outlist = vlist[1]; |
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| 172 | GLuint p; |
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| 173 | GLubyte *clipmask = VB->ClipMask; |
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| 174 | GLuint n = 3; |
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| 175 | |||
| 176 | ASSIGN_3V(inlist, v2, v0, v1 ); /* pv rotated to slot zero */ |
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| 177 | |||
| 178 | VB->LastClipped = VB->FirstClipped; |
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| 179 | |||
| 180 | if (mask & 0x3f) { |
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| 181 | POLY_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 ); |
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| 182 | POLY_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 ); |
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| 183 | POLY_CLIP( CLIP_TOP_BIT, 0, -1, 0, 1 ); |
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| 184 | POLY_CLIP( CLIP_BOTTOM_BIT, 0, 1, 0, 1 ); |
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| 185 | POLY_CLIP( CLIP_FAR_BIT, 0, 0, -1, 1 ); |
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| 186 | POLY_CLIP( CLIP_NEAR_BIT, 0, 0, 1, 1 ); |
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| 187 | } |
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| 188 | |||
| 189 | if (mask & CLIP_USER_BIT) { |
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| 190 | for (p=0;p<MAX_CLIP_PLANES;p++) { |
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| 191 | if (ctx->Transform.ClipPlanesEnabled & (1 << p)) { |
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| 192 | const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; |
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| 193 | const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; |
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| 194 | const GLfloat c = ctx->Transform._ClipUserPlane[p][2]; |
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| 195 | const GLfloat d = ctx->Transform._ClipUserPlane[p][3]; |
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| 196 | POLY_CLIP( CLIP_USER_BIT, a, b, c, d ); |
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| 197 | } |
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| 198 | } |
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| 199 | } |
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| 200 | |||
| 201 | if (ctx->_TriangleCaps & DD_FLATSHADE) { |
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| 202 | if (pv != inlist[0]) { |
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| 203 | ASSERT( inlist[0] >= VB->FirstClipped ); |
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| 204 | tnl->Driver.Render.CopyPV( ctx, inlist[0], pv ); |
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| 205 | } |
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| 206 | } |
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| 207 | |||
| 208 | tnl->Driver.Render.ClippedPolygon( ctx, inlist, n ); |
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| 209 | } |
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| 210 | |||
| 211 | |||
| 212 | /* Clip a quad against the viewport and user clip planes. |
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| 213 | */ |
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| 214 | static INLINE void |
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| 215 | TAG(clip_quad)( GLcontext *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint v3, |
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| 216 | GLubyte mask ) |
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| 217 | { |
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| 218 | TNLcontext *tnl = TNL_CONTEXT(ctx); |
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| 219 | struct vertex_buffer *VB = &tnl->vb; |
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| 220 | interp_func interp = tnl->Driver.Render.Interp; |
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| 221 | GLfloat (*coord)[4] = VB->ClipPtr->data; |
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| 222 | GLuint pv = v3; |
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| 223 | GLuint vlist[2][MAX_CLIPPED_VERTICES]; |
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| 224 | GLuint *inlist = vlist[0], *outlist = vlist[1]; |
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| 225 | GLuint p; |
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| 226 | GLubyte *clipmask = VB->ClipMask; |
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| 227 | GLuint n = 4; |
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| 228 | |||
| 229 | ASSIGN_4V(inlist, v3, v0, v1, v2 ); /* pv rotated to slot zero */ |
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| 230 | |||
| 231 | VB->LastClipped = VB->FirstClipped; |
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| 232 | |||
| 233 | if (mask & 0x3f) { |
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| 234 | POLY_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 ); |
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| 235 | POLY_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 ); |
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| 236 | POLY_CLIP( CLIP_TOP_BIT, 0, -1, 0, 1 ); |
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| 237 | POLY_CLIP( CLIP_BOTTOM_BIT, 0, 1, 0, 1 ); |
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| 238 | POLY_CLIP( CLIP_FAR_BIT, 0, 0, -1, 1 ); |
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| 239 | POLY_CLIP( CLIP_NEAR_BIT, 0, 0, 1, 1 ); |
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| 240 | } |
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| 241 | |||
| 242 | if (mask & CLIP_USER_BIT) { |
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| 243 | for (p=0;p<MAX_CLIP_PLANES;p++) { |
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| 244 | if (ctx->Transform.ClipPlanesEnabled & (1 << p)) { |
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| 245 | const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; |
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| 246 | const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; |
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| 247 | const GLfloat c = ctx->Transform._ClipUserPlane[p][2]; |
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| 248 | const GLfloat d = ctx->Transform._ClipUserPlane[p][3]; |
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| 249 | POLY_CLIP( CLIP_USER_BIT, a, b, c, d ); |
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| 250 | } |
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| 251 | } |
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| 252 | } |
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| 253 | |||
| 254 | if (ctx->_TriangleCaps & DD_FLATSHADE) { |
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| 255 | if (pv != inlist[0]) { |
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| 256 | ASSERT( inlist[0] >= VB->FirstClipped ); |
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| 257 | tnl->Driver.Render.CopyPV( ctx, inlist[0], pv ); |
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| 258 | } |
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| 259 | } |
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| 260 | |||
| 261 | tnl->Driver.Render.ClippedPolygon( ctx, inlist, n ); |
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| 262 | } |
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| 263 | |||
| 264 | #undef W |
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| 265 | #undef Z |
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| 266 | #undef Y |
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| 267 | #undef X |
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| 268 | #undef SIZE |
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| 269 | #undef TAG |
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| 270 | #undef POLY_CLIP |
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| 271 | #undef LINE_CLIP |