1/************************************************************************** 2 * 3 * Copyright 2010, VMware, inc. 4 * All Rights Reserved. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the 8 * "Software"), to deal in the Software without restriction, including 9 * without limitation the rights to use, copy, modify, merge, publish, 10 * distribute, sub license, and/or sell copies of the Software, and to 11 * permit persons to whom the Software is furnished to do so, subject to 12 * the following conditions: 13 * 14 * The above copyright notice and this permission notice (including the 15 * next paragraph) shall be included in all copies or substantial portions 16 * of the Software. 17 * 18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. 21 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR 22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE 24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 25 * 26 **************************************************************************/ 27 28#include "util/u_bitcast.h" 29#include <math.h> 30 31static boolean TAG(do_cliptest)( struct pt_post_vs *pvs, 32 struct draw_vertex_info *info, 33 const struct draw_prim_info *prim_info ) 34{ 35 struct vertex_header *out = info->verts; 36 /* const */ float (*plane)[4] = pvs->draw->plane; 37 const unsigned pos = draw_current_shader_position_output(pvs->draw); 38 const unsigned cv = draw_current_shader_clipvertex_output(pvs->draw); 39 unsigned cd[2]; 40 const unsigned ef = pvs->draw->vs.edgeflag_output; 41 unsigned ucp_enable = pvs->draw->rasterizer->clip_plane_enable; 42 unsigned flags = (FLAGS); 43 unsigned need_pipeline = 0; 44 unsigned j; 45 unsigned i; 46 bool have_cd = false; 47 bool uses_vp_idx = draw_current_shader_uses_viewport_index(pvs->draw); 48 unsigned viewport_index_output = 49 draw_current_shader_viewport_index_output(pvs->draw); 50 int viewport_index = 0; 51 int num_written_clipdistance = 52 draw_current_shader_num_written_clipdistances(pvs->draw); 53 54 if (uses_vp_idx) { 55 viewport_index = u_bitcast_f2u(out->data[viewport_index_output][0]); 56 viewport_index = draw_clamp_viewport_idx(viewport_index); 57 } 58 59 cd[0] = draw_current_shader_ccdistance_output(pvs->draw, 0); 60 cd[1] = draw_current_shader_ccdistance_output(pvs->draw, 1); 61 62 if (cd[0] != pos || cd[1] != pos) 63 have_cd = true; 64 65 /* If clipdistance semantic has been written by the shader 66 * that means we're expected to do 'user plane clipping' */ 67 if (num_written_clipdistance && !(flags & DO_CLIP_USER)) { 68 flags |= DO_CLIP_USER; 69 ucp_enable = (1 << num_written_clipdistance) - 1; 70 } 71 72 assert(pos != -1); 73 unsigned prim_idx = 0, prim_vert_idx = 0; 74 for (j = 0; j < info->count; j++) { 75 float *position = out->data[pos]; 76 unsigned mask = 0x0; 77 78 if (uses_vp_idx) { 79 /* only change the viewport_index for the leading vertex */ 80 if (prim_vert_idx == (prim_info->primitive_lengths[prim_idx])) { 81 prim_idx++; 82 prim_vert_idx = 0; 83 viewport_index = u_bitcast_f2u(out->data[viewport_index_output][0]); 84 viewport_index = draw_clamp_viewport_idx(viewport_index); 85 } 86 prim_vert_idx++; 87 } 88 float *scale = pvs->draw->viewports[viewport_index].scale; 89 float *trans = pvs->draw->viewports[viewport_index].translate; 90 initialize_vertex_header(out); 91 92 if (flags & (DO_CLIP_XY | DO_CLIP_XY_GUARD_BAND | 93 DO_CLIP_FULL_Z | DO_CLIP_HALF_Z | DO_CLIP_USER)) { 94 float *clipvertex = position; 95 96 if ((flags & DO_CLIP_USER) && cv != pos) { 97 assert(cv != -1); 98 clipvertex = out->data[cv]; 99 } 100 101 for (i = 0; i < 4; i++) { 102 out->clip_pos[i] = position[i]; 103 } 104 105 /* Be careful with NaNs. Comparisons must be true for them. */ 106 /* Do the hardwired planes first: 107 */ 108 if (flags & DO_CLIP_XY_GUARD_BAND) { 109 if (!(-0.50 * position[0] + position[3] >= 0)) mask |= (1<<0); 110 if (!( 0.50 * position[0] + position[3] >= 0)) mask |= (1<<1); 111 if (!(-0.50 * position[1] + position[3] >= 0)) mask |= (1<<2); 112 if (!( 0.50 * position[1] + position[3] >= 0)) mask |= (1<<3); 113 } 114 else if (flags & DO_CLIP_XY) { 115 if (!(-position[0] + position[3] >= 0)) mask |= (1<<0); 116 if (!( position[0] + position[3] >= 0)) mask |= (1<<1); 117 if (!(-position[1] + position[3] >= 0)) mask |= (1<<2); 118 if (!( position[1] + position[3] >= 0)) mask |= (1<<3); 119 } 120 121 /* Clip Z planes according to full cube, half cube or none. 122 */ 123 if (flags & DO_CLIP_FULL_Z) { 124 if (!( position[2] + position[3] >= 0)) mask |= (1<<4); 125 if (!(-position[2] + position[3] >= 0)) mask |= (1<<5); 126 } 127 else if (flags & DO_CLIP_HALF_Z) { 128 if (!( position[2] >= 0)) mask |= (1<<4); 129 if (!(-position[2] + position[3] >= 0)) mask |= (1<<5); 130 } 131 132 if (flags & DO_CLIP_USER) { 133 unsigned ucp_mask = ucp_enable; 134 135 while (ucp_mask) { 136 unsigned plane_idx = ffs(ucp_mask)-1; 137 ucp_mask &= ~(1 << plane_idx); 138 plane_idx += 6; 139 140 /* 141 * for user clipping check if we have a clip distance output 142 * and the shader has written to it, otherwise use clipvertex 143 * to decide when the plane is clipping. 144 */ 145 if (have_cd && num_written_clipdistance) { 146 float clipdist; 147 i = plane_idx - 6; 148 /* first four clip distance in first vector etc. */ 149 if (i < 4) 150 clipdist = out->data[cd[0]][i]; 151 else 152 clipdist = out->data[cd[1]][i-4]; 153 if (clipdist < 0 || util_is_inf_or_nan(clipdist)) 154 mask |= 1 << plane_idx; 155 } else { 156 if (!(dot4(clipvertex, plane[plane_idx]) >= 0)) 157 mask |= 1 << plane_idx; 158 } 159 } 160 } 161 162 out->clipmask = mask; 163 need_pipeline |= out->clipmask; 164 } 165 166 /* 167 * Transform the vertex position from clip coords to window coords, 168 * if the vertex is unclipped. 169 */ 170 if ((flags & DO_VIEWPORT) && mask == 0) 171 { 172 /* divide by w */ 173 float w = 1.0f / position[3]; 174 175 /* Viewport mapping */ 176 position[0] = position[0] * w * scale[0] + trans[0]; 177 position[1] = position[1] * w * scale[1] + trans[1]; 178 position[2] = position[2] * w * scale[2] + trans[2]; 179 position[3] = w; 180 } 181#ifdef DEBUG 182 /* For debug builds, set the clipped vertex's window coordinate 183 * to NaN to help catch potential errors later. 184 */ 185 else { 186 position[0] = 187 position[1] = 188 position[2] = 189 position[3] = NAN; 190 } 191#endif 192 193 if ((flags & DO_EDGEFLAG) && ef) { 194 const float *edgeflag = out->data[ef]; 195 out->edgeflag = !(edgeflag[0] != 1.0f); 196 need_pipeline |= !out->edgeflag; 197 } 198 199 out = (struct vertex_header *)( (char *)out + info->stride ); 200 } 201 return need_pipeline != 0; 202} 203 204 205#undef FLAGS 206#undef TAG 207