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56 | pj | 1 | /* $Id: t_vb_cliptmp.h,v 1.1 2003-02-28 11:48:07 pj Exp $ */ |
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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 |