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
29
TAG(do_cliptest)30 static boolean TAG(do_cliptest)( struct pt_post_vs *pvs,
31 struct draw_vertex_info *info )
32 {
33 struct vertex_header *out = info->verts;
34 const float *scale = pvs->draw->viewport.scale;
35 const float *trans = pvs->draw->viewport.translate;
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 const unsigned ucp_enable = pvs->draw->rasterizer->clip_plane_enable;
42 const unsigned flags = (FLAGS);
43 unsigned need_pipeline = 0;
44 unsigned j;
45 unsigned i;
46 bool have_cd = false;
47 cd[0] = draw_current_shader_clipdistance_output(pvs->draw, 0);
48 cd[1] = draw_current_shader_clipdistance_output(pvs->draw, 1);
49
50 if (cd[0] != pos || cd[1] != pos)
51 have_cd = true;
52
53 for (j = 0; j < info->count; j++) {
54 float *position = out->data[pos];
55 unsigned mask = 0x0;
56
57 initialize_vertex_header(out);
58
59 if (flags & (DO_CLIP_XY | DO_CLIP_XY_GUARD_BAND |
60 DO_CLIP_FULL_Z | DO_CLIP_HALF_Z | DO_CLIP_USER)) {
61 float *clipvertex = position;
62
63 if ((flags & DO_CLIP_USER) && cv != pos)
64 clipvertex = out->data[cv];
65
66 for (i = 0; i < 4; i++) {
67 out->clip[i] = clipvertex[i];
68 out->pre_clip_pos[i] = position[i];
69 }
70
71 /* Do the hardwired planes first:
72 */
73 if (flags & DO_CLIP_XY_GUARD_BAND) {
74 if (-0.50 * position[0] + position[3] < 0) mask |= (1<<0);
75 if ( 0.50 * position[0] + position[3] < 0) mask |= (1<<1);
76 if (-0.50 * position[1] + position[3] < 0) mask |= (1<<2);
77 if ( 0.50 * position[1] + position[3] < 0) mask |= (1<<3);
78 }
79 else if (flags & DO_CLIP_XY) {
80 if (-position[0] + position[3] < 0) mask |= (1<<0);
81 if ( position[0] + position[3] < 0) mask |= (1<<1);
82 if (-position[1] + position[3] < 0) mask |= (1<<2);
83 if ( position[1] + position[3] < 0) mask |= (1<<3);
84 }
85
86 /* Clip Z planes according to full cube, half cube or none.
87 */
88 if (flags & DO_CLIP_FULL_Z) {
89 if ( position[2] + position[3] < 0) mask |= (1<<4);
90 if (-position[2] + position[3] < 0) mask |= (1<<5);
91 }
92 else if (flags & DO_CLIP_HALF_Z) {
93 if ( position[2] < 0) mask |= (1<<4);
94 if (-position[2] + position[3] < 0) mask |= (1<<5);
95 }
96
97 if (flags & DO_CLIP_USER) {
98 unsigned ucp_mask = ucp_enable;
99 int num_written_clipdistance = pvs->draw->vs.vertex_shader->info.num_written_clipdistance;
100 while (ucp_mask) {
101 unsigned plane_idx = ffs(ucp_mask)-1;
102 ucp_mask &= ~(1 << plane_idx);
103 plane_idx += 6;
104
105 /*
106 * for user clipping check if we have a clip distance output
107 * and the shader has written to it, otherwise use clipvertex
108 * to decide when the plane is clipping.
109 */
110 if (have_cd && num_written_clipdistance) {
111 float clipdist;
112 i = plane_idx - 6;
113 out->have_clipdist = 1;
114 /* first four clip distance in first vector etc. */
115 if (i < 4)
116 clipdist = out->data[cd[0]][i];
117 else
118 clipdist = out->data[cd[1]][i-4];
119 if (clipdist < 0)
120 mask |= 1 << plane_idx;
121 } else {
122 if (dot4(clipvertex, plane[plane_idx]) < 0)
123 mask |= 1 << plane_idx;
124 }
125 }
126 }
127
128 out->clipmask = mask;
129 need_pipeline |= out->clipmask;
130 }
131
132 if ((flags & DO_VIEWPORT) && mask == 0)
133 {
134 /* divide by w */
135 float w = 1.0f / position[3];
136
137 /* Viewport mapping */
138 position[0] = position[0] * w * scale[0] + trans[0];
139 position[1] = position[1] * w * scale[1] + trans[1];
140 position[2] = position[2] * w * scale[2] + trans[2];
141 position[3] = w;
142 }
143
144 if ((flags & DO_EDGEFLAG) && ef) {
145 const float *edgeflag = out->data[ef];
146 out->edgeflag = !(edgeflag[0] != 1.0f);
147 need_pipeline |= !out->edgeflag;
148 }
149
150 out = (struct vertex_header *)( (char *)out + info->stride );
151 }
152
153 return need_pipeline != 0;
154 }
155
156
157 #undef FLAGS
158 #undef TAG
159