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| 1901 | serge | 1 | /* |
| 2 | * Mesa 3-D graphics library |
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| 3 | * Version: 6.5.2 |
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| 4 | * |
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| 5 | * Copyright (C) 1999-2006 Brian Paul All Rights Reserved. |
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| 6 | * |
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| 7 | * Permission is hereby granted, free of charge, to any person obtaining a |
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| 8 | * copy of this software and associated documentation files (the "Software"), |
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| 9 | * to deal in the Software without restriction, including without limitation |
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| 10 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
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| 11 | * and/or sell copies of the Software, and to permit persons to whom the |
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| 12 | * Software is furnished to do so, subject to the following conditions: |
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| 13 | * |
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| 14 | * The above copyright notice and this permission notice shall be included |
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| 15 | * in all copies or substantial portions of the Software. |
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| 16 | * |
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| 17 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
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| 18 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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| 19 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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| 20 | * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN |
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| 21 | * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
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| 22 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
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| 23 | * |
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| 24 | * Authors: |
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| 25 | * Keith Whitwell |
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| 26 | */ |
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| 27 | |||
| 28 | |||
| 29 | #define CLIP_DOTPROD(K, A, B, C, D) X(K)*A + Y(K)*B + Z(K)*C + W(K)*D |
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| 30 | |||
| 31 | #define POLY_CLIP( PLANE_BIT, A, B, C, D ) \ |
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| 32 | do { \ |
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| 33 | if (mask & PLANE_BIT) { \ |
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| 34 | GLuint idxPrev = inlist[0]; \ |
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| 35 | GLfloat dpPrev = CLIP_DOTPROD(idxPrev, A, B, C, D ); \ |
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| 36 | GLuint outcount = 0; \ |
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| 37 | GLuint i; \ |
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| 38 | \ |
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| 39 | inlist[n] = inlist[0]; /* prevent rotation of vertices */ \ |
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| 40 | for (i = 1; i <= n; i++) { \ |
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| 41 | GLuint idx = inlist[i]; \ |
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| 42 | GLfloat dp = CLIP_DOTPROD(idx, A, B, C, D ); \ |
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| 43 | \ |
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| 44 | if (!IS_NEGATIVE(dpPrev)) { \ |
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| 45 | outlist[outcount++] = idxPrev; \ |
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| 46 | } \ |
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| 47 | \ |
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| 48 | if (DIFFERENT_SIGNS(dp, dpPrev)) { \ |
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| 49 | if (IS_NEGATIVE(dp)) { \ |
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| 50 | /* Going out of bounds. Avoid division by zero as we \ |
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| 51 | * know dp != dpPrev from DIFFERENT_SIGNS, above. \ |
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| 52 | */ \ |
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| 53 | GLfloat t = dp / (dp - dpPrev); \ |
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| 54 | INTERP_4F( t, coord[newvert], coord[idx], coord[idxPrev]); \ |
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| 55 | interp( ctx, t, newvert, idx, idxPrev, GL_TRUE ); \ |
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| 56 | } else { \ |
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| 57 | /* Coming back in. \ |
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| 58 | */ \ |
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| 59 | GLfloat t = dpPrev / (dpPrev - dp); \ |
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| 60 | INTERP_4F( t, coord[newvert], coord[idxPrev], coord[idx]); \ |
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| 61 | interp( ctx, t, newvert, idxPrev, idx, GL_FALSE ); \ |
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| 62 | } \ |
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| 63 | outlist[outcount++] = newvert++; \ |
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| 64 | } \ |
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| 65 | \ |
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| 66 | idxPrev = idx; \ |
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| 67 | dpPrev = dp; \ |
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| 68 | } \ |
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| 69 | \ |
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| 70 | if (outcount < 3) \ |
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| 71 | return; \ |
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| 72 | \ |
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| 73 | { \ |
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| 74 | GLuint *tmp = inlist; \ |
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| 75 | inlist = outlist; \ |
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| 76 | outlist = tmp; \ |
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| 77 | n = outcount; \ |
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| 78 | } \ |
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| 79 | } \ |
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| 80 | } while (0) |
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| 81 | |||
| 82 | |||
| 83 | #define LINE_CLIP(PLANE_BIT, A, B, C, D ) \ |
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| 84 | do { \ |
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| 85 | if (mask & PLANE_BIT) { \ |
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| 86 | const GLfloat dp0 = CLIP_DOTPROD( v0, A, B, C, D ); \ |
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| 87 | const GLfloat dp1 = CLIP_DOTPROD( v1, A, B, C, D ); \ |
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| 88 | const GLboolean neg_dp0 = IS_NEGATIVE(dp0); \ |
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| 89 | const GLboolean neg_dp1 = IS_NEGATIVE(dp1); \ |
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| 90 | \ |
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| 91 | /* For regular clipping, we know from the clipmask that one \ |
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| 92 | * (or both) of these must be negative (otherwise we wouldn't \ |
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| 93 | * be here). \ |
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| 94 | * For userclip, there is only a single bit for all active \ |
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| 95 | * planes, so we can end up here when there is nothing to do, \ |
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| 96 | * hence the second IS_NEGATIVE() test: \ |
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| 97 | */ \ |
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| 98 | if (neg_dp0 && neg_dp1) \ |
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| 99 | return; /* both vertices outside clip plane: discard */ \ |
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| 100 | \ |
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| 101 | if (neg_dp1) { \ |
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| 102 | GLfloat t = dp1 / (dp1 - dp0); \ |
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| 103 | if (t > t1) t1 = t; \ |
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| 104 | } else if (neg_dp0) { \ |
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| 105 | GLfloat t = dp0 / (dp0 - dp1); \ |
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| 106 | if (t > t0) t0 = t; \ |
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| 107 | } \ |
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| 108 | if (t0 + t1 >= 1.0) \ |
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| 109 | return; /* discard */ \ |
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| 110 | } \ |
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| 111 | } while (0) |
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| 112 | |||
| 113 | |||
| 114 | |||
| 115 | /* Clip a line against the viewport and user clip planes. |
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| 116 | */ |
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| 117 | static INLINE void |
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| 118 | TAG(clip_line)( struct gl_context *ctx, GLuint v0, GLuint v1, GLubyte mask ) |
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| 119 | { |
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| 120 | TNLcontext *tnl = TNL_CONTEXT(ctx); |
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| 121 | struct vertex_buffer *VB = &tnl->vb; |
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| 122 | tnl_interp_func interp = tnl->Driver.Render.Interp; |
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| 123 | GLfloat (*coord)[4] = VB->ClipPtr->data; |
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| 124 | GLuint newvert = VB->Count; |
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| 125 | GLfloat t0 = 0; |
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| 126 | GLfloat t1 = 0; |
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| 127 | GLuint p; |
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| 128 | const GLuint v0_orig = v0; |
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| 129 | |||
| 130 | if (mask & CLIP_FRUSTUM_BITS) { |
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| 131 | LINE_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 ); |
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| 132 | LINE_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 ); |
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| 133 | LINE_CLIP( CLIP_TOP_BIT, 0, -1, 0, 1 ); |
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| 134 | LINE_CLIP( CLIP_BOTTOM_BIT, 0, 1, 0, 1 ); |
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| 135 | LINE_CLIP( CLIP_FAR_BIT, 0, 0, -1, 1 ); |
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| 136 | LINE_CLIP( CLIP_NEAR_BIT, 0, 0, 1, 1 ); |
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| 137 | } |
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| 138 | |||
| 139 | if (mask & CLIP_USER_BIT) { |
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| 140 | for (p = 0; p < ctx->Const.MaxClipPlanes; p++) { |
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| 141 | if (ctx->Transform.ClipPlanesEnabled & (1 << p)) { |
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| 142 | const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; |
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| 143 | const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; |
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| 144 | const GLfloat c = ctx->Transform._ClipUserPlane[p][2]; |
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| 145 | const GLfloat d = ctx->Transform._ClipUserPlane[p][3]; |
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| 146 | LINE_CLIP( CLIP_USER_BIT, a, b, c, d ); |
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| 147 | } |
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| 148 | } |
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| 149 | } |
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| 150 | |||
| 151 | if (VB->ClipMask[v0]) { |
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| 152 | INTERP_4F( t0, coord[newvert], coord[v0], coord[v1] ); |
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| 153 | interp( ctx, t0, newvert, v0, v1, GL_FALSE ); |
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| 154 | v0 = newvert; |
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| 155 | newvert++; |
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| 156 | } |
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| 157 | else { |
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| 158 | ASSERT(t0 == 0.0); |
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| 159 | } |
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| 160 | |||
| 161 | /* Note: we need to use vertex v0_orig when computing the new |
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| 162 | * interpolated/clipped vertex position, not the current v0 which |
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| 163 | * may have got set when we clipped the other end of the line! |
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| 164 | */ |
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| 165 | if (VB->ClipMask[v1]) { |
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| 166 | INTERP_4F( t1, coord[newvert], coord[v1], coord[v0_orig] ); |
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| 167 | interp( ctx, t1, newvert, v1, v0_orig, GL_FALSE ); |
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| 168 | |||
| 169 | if (ctx->Light.ShadeModel == GL_FLAT) |
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| 170 | tnl->Driver.Render.CopyPV( ctx, newvert, v1 ); |
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| 171 | |||
| 172 | v1 = newvert; |
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| 173 | |||
| 174 | newvert++; |
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| 175 | } |
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| 176 | else { |
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| 177 | ASSERT(t1 == 0.0); |
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| 178 | } |
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| 179 | |||
| 180 | tnl->Driver.Render.ClippedLine( ctx, v0, v1 ); |
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| 181 | } |
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| 182 | |||
| 183 | |||
| 184 | /* Clip a triangle against the viewport and user clip planes. |
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| 185 | */ |
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| 186 | static INLINE void |
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| 187 | TAG(clip_tri)( struct gl_context *ctx, GLuint v0, GLuint v1, GLuint v2, GLubyte mask ) |
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| 188 | { |
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| 189 | TNLcontext *tnl = TNL_CONTEXT(ctx); |
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| 190 | struct vertex_buffer *VB = &tnl->vb; |
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| 191 | tnl_interp_func interp = tnl->Driver.Render.Interp; |
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| 192 | GLuint newvert = VB->Count; |
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| 193 | GLfloat (*coord)[4] = VB->ClipPtr->data; |
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| 194 | GLuint pv = v2; |
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| 195 | GLuint vlist[2][MAX_CLIPPED_VERTICES]; |
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| 196 | GLuint *inlist = vlist[0], *outlist = vlist[1]; |
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| 197 | GLuint p; |
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| 198 | GLuint n = 3; |
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| 199 | |||
| 200 | ASSIGN_3V(inlist, v2, v0, v1 ); /* pv rotated to slot zero */ |
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| 201 | |||
| 202 | if (0) { |
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| 203 | /* print pre-clip vertex coords */ |
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| 204 | GLuint i, j; |
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| 205 | printf("pre clip:\n"); |
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| 206 | for (i = 0; i < n; i++) { |
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| 207 | j = inlist[i]; |
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| 208 | printf(" %u: %u: %f, %f, %f, %f\n", |
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| 209 | i, j, |
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| 210 | coord[j][0], coord[j][1], coord[j][2], coord[j][3]); |
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| 211 | assert(!IS_INF_OR_NAN(coord[j][0])); |
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| 212 | assert(!IS_INF_OR_NAN(coord[j][1])); |
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| 213 | assert(!IS_INF_OR_NAN(coord[j][2])); |
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| 214 | assert(!IS_INF_OR_NAN(coord[j][3])); |
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| 215 | } |
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| 216 | } |
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| 217 | |||
| 218 | |||
| 219 | if (mask & CLIP_FRUSTUM_BITS) { |
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| 220 | POLY_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 ); |
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| 221 | POLY_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 ); |
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| 222 | POLY_CLIP( CLIP_TOP_BIT, 0, -1, 0, 1 ); |
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| 223 | POLY_CLIP( CLIP_BOTTOM_BIT, 0, 1, 0, 1 ); |
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| 224 | POLY_CLIP( CLIP_FAR_BIT, 0, 0, -1, 1 ); |
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| 225 | POLY_CLIP( CLIP_NEAR_BIT, 0, 0, 1, 1 ); |
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| 226 | } |
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| 227 | |||
| 228 | if (mask & CLIP_USER_BIT) { |
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| 229 | for (p = 0; p < ctx->Const.MaxClipPlanes; p++) { |
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| 230 | if (ctx->Transform.ClipPlanesEnabled & (1 << p)) { |
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| 231 | const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; |
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| 232 | const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; |
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| 233 | const GLfloat c = ctx->Transform._ClipUserPlane[p][2]; |
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| 234 | const GLfloat d = ctx->Transform._ClipUserPlane[p][3]; |
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| 235 | POLY_CLIP( CLIP_USER_BIT, a, b, c, d ); |
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| 236 | } |
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| 237 | } |
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| 238 | } |
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| 239 | |||
| 240 | if (ctx->Light.ShadeModel == GL_FLAT) { |
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| 241 | if (pv != inlist[0]) { |
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| 242 | ASSERT( inlist[0] >= VB->Count ); |
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| 243 | tnl->Driver.Render.CopyPV( ctx, inlist[0], pv ); |
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| 244 | } |
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| 245 | } |
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| 246 | |||
| 247 | if (0) { |
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| 248 | /* print post-clip vertex coords */ |
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| 249 | GLuint i, j; |
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| 250 | printf("post clip:\n"); |
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| 251 | for (i = 0; i < n; i++) { |
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| 252 | j = inlist[i]; |
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| 253 | printf(" %u: %u: %f, %f, %f, %f\n", |
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| 254 | i, j, |
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| 255 | coord[j][0], coord[j][1], coord[j][2], coord[j][3]); |
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| 256 | } |
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| 257 | } |
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| 258 | |||
| 259 | tnl->Driver.Render.ClippedPolygon( ctx, inlist, n ); |
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| 260 | } |
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| 261 | |||
| 262 | |||
| 263 | /* Clip a quad against the viewport and user clip planes. |
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| 264 | */ |
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| 265 | static INLINE void |
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| 266 | TAG(clip_quad)( struct gl_context *ctx, GLuint v0, GLuint v1, GLuint v2, GLuint v3, |
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| 267 | GLubyte mask ) |
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| 268 | { |
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| 269 | TNLcontext *tnl = TNL_CONTEXT(ctx); |
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| 270 | struct vertex_buffer *VB = &tnl->vb; |
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| 271 | tnl_interp_func interp = tnl->Driver.Render.Interp; |
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| 272 | GLuint newvert = VB->Count; |
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| 273 | GLfloat (*coord)[4] = VB->ClipPtr->data; |
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| 274 | GLuint pv = v3; |
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| 275 | GLuint vlist[2][MAX_CLIPPED_VERTICES]; |
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| 276 | GLuint *inlist = vlist[0], *outlist = vlist[1]; |
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| 277 | GLuint p; |
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| 278 | GLuint n = 4; |
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| 279 | |||
| 280 | ASSIGN_4V(inlist, v3, v0, v1, v2 ); /* pv rotated to slot zero */ |
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| 281 | |||
| 282 | if (mask & CLIP_FRUSTUM_BITS) { |
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| 283 | POLY_CLIP( CLIP_RIGHT_BIT, -1, 0, 0, 1 ); |
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| 284 | POLY_CLIP( CLIP_LEFT_BIT, 1, 0, 0, 1 ); |
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| 285 | POLY_CLIP( CLIP_TOP_BIT, 0, -1, 0, 1 ); |
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| 286 | POLY_CLIP( CLIP_BOTTOM_BIT, 0, 1, 0, 1 ); |
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| 287 | POLY_CLIP( CLIP_FAR_BIT, 0, 0, -1, 1 ); |
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| 288 | POLY_CLIP( CLIP_NEAR_BIT, 0, 0, 1, 1 ); |
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| 289 | } |
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| 290 | |||
| 291 | if (mask & CLIP_USER_BIT) { |
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| 292 | for (p = 0; p < ctx->Const.MaxClipPlanes; p++) { |
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| 293 | if (ctx->Transform.ClipPlanesEnabled & (1 << p)) { |
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| 294 | const GLfloat a = ctx->Transform._ClipUserPlane[p][0]; |
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| 295 | const GLfloat b = ctx->Transform._ClipUserPlane[p][1]; |
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| 296 | const GLfloat c = ctx->Transform._ClipUserPlane[p][2]; |
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| 297 | const GLfloat d = ctx->Transform._ClipUserPlane[p][3]; |
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| 298 | POLY_CLIP( CLIP_USER_BIT, a, b, c, d ); |
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| 299 | } |
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| 300 | } |
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| 301 | } |
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| 302 | |||
| 303 | if (ctx->Light.ShadeModel == GL_FLAT) { |
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| 304 | if (pv != inlist[0]) { |
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| 305 | ASSERT( inlist[0] >= VB->Count ); |
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| 306 | tnl->Driver.Render.CopyPV( ctx, inlist[0], pv ); |
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| 307 | } |
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| 308 | } |
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| 309 | |||
| 310 | tnl->Driver.Render.ClippedPolygon( ctx, inlist, n ); |
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| 311 | } |
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| 312 | |||
| 313 | #undef W |
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| 314 | #undef Z |
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| 315 | #undef Y |
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| 316 | #undef X |
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| 317 | #undef SIZE |
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| 318 | #undef TAG |
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| 319 | #undef POLY_CLIP |
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| 320 | #undef LINE_CLIP |