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
TAG(do_cliptest)30 static boolean TAG(do_cliptest)( struct pt_post_vs *pvs,
31 struct draw_vertex_info *info,
32 const struct draw_prim_info *prim_info )
33 {
34 struct vertex_header *out = info->verts;
35 /* const */ float (*plane)[4] = pvs->draw->plane;
36 const unsigned pos = draw_current_shader_position_output(pvs->draw);
37 const unsigned cv = draw_current_shader_clipvertex_output(pvs->draw);
38 unsigned cd[2];
39 const unsigned ef = pvs->draw->vs.edgeflag_output;
40 unsigned ucp_enable = pvs->draw->rasterizer->clip_plane_enable;
41 unsigned flags = (FLAGS);
42 unsigned need_pipeline = 0;
43 unsigned j;
44 unsigned i;
45 bool have_cd = false;
46 bool uses_vp_idx = draw_current_shader_uses_viewport_index(pvs->draw);
47 unsigned viewport_index_output =
48 draw_current_shader_viewport_index_output(pvs->draw);
49 int viewport_index = 0;
50 int num_written_clipdistance =
51 draw_current_shader_num_written_clipdistances(pvs->draw);
52
53 if (uses_vp_idx) {
54 viewport_index = u_bitcast_f2u(out->data[viewport_index_output][0]);
55 viewport_index = draw_clamp_viewport_idx(viewport_index);
56 }
57
58 cd[0] = draw_current_shader_ccdistance_output(pvs->draw, 0);
59 cd[1] = draw_current_shader_ccdistance_output(pvs->draw, 1);
60
61 if (cd[0] != pos || cd[1] != pos)
62 have_cd = true;
63
64 /* If clipdistance semantic has been written by the shader
65 * that means we're expected to do 'user plane clipping' */
66 if (num_written_clipdistance && !(flags & DO_CLIP_USER)) {
67 flags |= DO_CLIP_USER;
68 ucp_enable = (1 << num_written_clipdistance) - 1;
69 }
70
71 assert(pos != -1);
72 unsigned prim_idx = 0, prim_vert_idx = 0;
73 for (j = 0; j < info->count; j++) {
74 float *position = out->data[pos];
75 unsigned mask = 0x0;
76
77 if (uses_vp_idx) {
78 /* only change the viewport_index for the leading vertex */
79 if (prim_vert_idx == (prim_info->primitive_lengths[prim_idx])) {
80 prim_idx++;
81 prim_vert_idx = 0;
82 viewport_index = u_bitcast_f2u(out->data[viewport_index_output][0]);
83 viewport_index = draw_clamp_viewport_idx(viewport_index);
84 }
85 prim_vert_idx++;
86 }
87 float *scale = pvs->draw->viewports[viewport_index].scale;
88 float *trans = pvs->draw->viewports[viewport_index].translate;
89 initialize_vertex_header(out);
90
91 if (flags & (DO_CLIP_XY | DO_CLIP_XY_GUARD_BAND |
92 DO_CLIP_FULL_Z | DO_CLIP_HALF_Z | DO_CLIP_USER)) {
93 float *clipvertex = position;
94
95 if ((flags & DO_CLIP_USER) && cv != pos) {
96 assert(cv != -1);
97 clipvertex = out->data[cv];
98 }
99
100 for (i = 0; i < 4; i++) {
101 out->clip_pos[i] = position[i];
102 }
103
104 /* Be careful with NaNs. Comparisons must be true for them. */
105 /* Do the hardwired planes first:
106 */
107 if (flags & DO_CLIP_XY_GUARD_BAND) {
108 if (!(-0.50 * position[0] + position[3] >= 0)) mask |= (1<<0);
109 if (!( 0.50 * position[0] + position[3] >= 0)) mask |= (1<<1);
110 if (!(-0.50 * position[1] + position[3] >= 0)) mask |= (1<<2);
111 if (!( 0.50 * position[1] + position[3] >= 0)) mask |= (1<<3);
112 }
113 else if (flags & DO_CLIP_XY) {
114 if (!(-position[0] + position[3] >= 0)) mask |= (1<<0);
115 if (!( position[0] + position[3] >= 0)) mask |= (1<<1);
116 if (!(-position[1] + position[3] >= 0)) mask |= (1<<2);
117 if (!( position[1] + position[3] >= 0)) mask |= (1<<3);
118 }
119
120 /* Clip Z planes according to full cube, half cube or none.
121 */
122 if (flags & DO_CLIP_FULL_Z) {
123 if (!( position[2] + position[3] >= 0)) mask |= (1<<4);
124 if (!(-position[2] + position[3] >= 0)) mask |= (1<<5);
125 }
126 else if (flags & DO_CLIP_HALF_Z) {
127 if (!( position[2] >= 0)) mask |= (1<<4);
128 if (!(-position[2] + position[3] >= 0)) mask |= (1<<5);
129 }
130
131 if (flags & DO_CLIP_USER) {
132 unsigned ucp_mask = ucp_enable;
133
134 while (ucp_mask) {
135 unsigned plane_idx = ffs(ucp_mask)-1;
136 ucp_mask &= ~(1 << plane_idx);
137 plane_idx += 6;
138
139 /*
140 * for user clipping check if we have a clip distance output
141 * and the shader has written to it, otherwise use clipvertex
142 * to decide when the plane is clipping.
143 */
144 if (have_cd && num_written_clipdistance) {
145 float clipdist;
146 i = plane_idx - 6;
147 /* first four clip distance in first vector etc. */
148 if (i < 4)
149 clipdist = out->data[cd[0]][i];
150 else
151 clipdist = out->data[cd[1]][i-4];
152 if (clipdist < 0 || util_is_inf_or_nan(clipdist))
153 mask |= 1 << plane_idx;
154 } else {
155 if (!(dot4(clipvertex, plane[plane_idx]) >= 0))
156 mask |= 1 << plane_idx;
157 }
158 }
159 }
160
161 out->clipmask = mask;
162 need_pipeline |= out->clipmask;
163 }
164
165 /*
166 * Transform the vertex position from clip coords to window coords,
167 * if the vertex is unclipped.
168 */
169 if ((flags & DO_VIEWPORT) && mask == 0)
170 {
171 /* divide by w */
172 float w = 1.0f / position[3];
173
174 /* Viewport mapping */
175 position[0] = position[0] * w * scale[0] + trans[0];
176 position[1] = position[1] * w * scale[1] + trans[1];
177 position[2] = position[2] * w * scale[2] + trans[2];
178 position[3] = w;
179 }
180 #ifdef DEBUG
181 /* For debug builds, set the clipped vertex's window coordinate
182 * to NaN to help catch potential errors later.
183 */
184 else {
185 float zero = 0.0f;
186 position[0] =
187 position[1] =
188 position[2] =
189 position[3] = zero / zero; /* MSVC doesn't accept 0.0 / 0.0 */
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