1 /*
2 * Copyright 2010 Marek Olšák <maraeo@gmail.com>
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * on the rights to use, copy, modify, merge, publish, distribute, sub
8 * license, and/or sell copies of the Software, and to permit persons to whom
9 * the Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
19 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
20 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
21 * USE OR OTHER DEALINGS IN THE SOFTWARE. */
22
23 /**
24 * The two-sided stencil reference value fallback for r3xx-r4xx chips.
25 * These chips support two-sided stencil functions but they do not support
26 * a two-sided reference value.
27 *
28 * The functions below split every draw call which uses the two-sided
29 * reference value into two draw calls -- the first one renders front faces
30 * and the second renders back faces with the other reference value.
31 */
32
33 #include "r300_context.h"
34 #include "r300_reg.h"
35
36 struct r300_stencilref_context {
37 void (*draw_vbo)(struct pipe_context *pipe,
38 const struct pipe_draw_info *info);
39
40 uint32_t rs_cull_mode;
41 uint32_t zb_stencilrefmask;
42 ubyte ref_value_front;
43 };
44
r300_stencilref_needed(struct r300_context * r300)45 static boolean r300_stencilref_needed(struct r300_context *r300)
46 {
47 struct r300_dsa_state *dsa = (struct r300_dsa_state*)r300->dsa_state.state;
48
49 return dsa->two_sided_stencil_ref ||
50 (dsa->two_sided &&
51 r300->stencil_ref.ref_value[0] != r300->stencil_ref.ref_value[1]);
52 }
53
54 /* Set drawing for front faces. */
r300_stencilref_begin(struct r300_context * r300)55 static void r300_stencilref_begin(struct r300_context *r300)
56 {
57 struct r300_stencilref_context *sr = r300->stencilref_fallback;
58 struct r300_rs_state *rs = (struct r300_rs_state*)r300->rs_state.state;
59 struct r300_dsa_state *dsa = (struct r300_dsa_state*)r300->dsa_state.state;
60
61 /* Save state. */
62 sr->rs_cull_mode = rs->cb_main[rs->cull_mode_index];
63 sr->zb_stencilrefmask = dsa->stencil_ref_mask;
64 sr->ref_value_front = r300->stencil_ref.ref_value[0];
65
66 /* We *cull* pixels, therefore no need to mask out the bits. */
67 rs->cb_main[rs->cull_mode_index] |= R300_CULL_BACK;
68
69 r300_mark_atom_dirty(r300, &r300->rs_state);
70 }
71
72 /* Set drawing for back faces. */
r300_stencilref_switch_side(struct r300_context * r300)73 static void r300_stencilref_switch_side(struct r300_context *r300)
74 {
75 struct r300_stencilref_context *sr = r300->stencilref_fallback;
76 struct r300_rs_state *rs = (struct r300_rs_state*)r300->rs_state.state;
77 struct r300_dsa_state *dsa = (struct r300_dsa_state*)r300->dsa_state.state;
78
79 rs->cb_main[rs->cull_mode_index] = sr->rs_cull_mode | R300_CULL_FRONT;
80 dsa->stencil_ref_mask = dsa->stencil_ref_bf;
81 r300->stencil_ref.ref_value[0] = r300->stencil_ref.ref_value[1];
82
83 r300_mark_atom_dirty(r300, &r300->rs_state);
84 r300_mark_atom_dirty(r300, &r300->dsa_state);
85 }
86
87 /* Restore the original state. */
r300_stencilref_end(struct r300_context * r300)88 static void r300_stencilref_end(struct r300_context *r300)
89 {
90 struct r300_stencilref_context *sr = r300->stencilref_fallback;
91 struct r300_rs_state *rs = (struct r300_rs_state*)r300->rs_state.state;
92 struct r300_dsa_state *dsa = (struct r300_dsa_state*)r300->dsa_state.state;
93
94 /* Restore state. */
95 rs->cb_main[rs->cull_mode_index] = sr->rs_cull_mode;
96 dsa->stencil_ref_mask = sr->zb_stencilrefmask;
97 r300->stencil_ref.ref_value[0] = sr->ref_value_front;
98
99 r300_mark_atom_dirty(r300, &r300->rs_state);
100 r300_mark_atom_dirty(r300, &r300->dsa_state);
101 }
102
r300_stencilref_draw_vbo(struct pipe_context * pipe,const struct pipe_draw_info * info)103 static void r300_stencilref_draw_vbo(struct pipe_context *pipe,
104 const struct pipe_draw_info *info)
105 {
106 struct r300_context *r300 = r300_context(pipe);
107 struct r300_stencilref_context *sr = r300->stencilref_fallback;
108
109 if (!r300_stencilref_needed(r300)) {
110 sr->draw_vbo(pipe, info);
111 } else {
112 r300_stencilref_begin(r300);
113 sr->draw_vbo(pipe, info);
114 r300_stencilref_switch_side(r300);
115 sr->draw_vbo(pipe, info);
116 r300_stencilref_end(r300);
117 }
118 }
119
r300_plug_in_stencil_ref_fallback(struct r300_context * r300)120 void r300_plug_in_stencil_ref_fallback(struct r300_context *r300)
121 {
122 r300->stencilref_fallback = CALLOC_STRUCT(r300_stencilref_context);
123
124 /* Save original draw function. */
125 r300->stencilref_fallback->draw_vbo = r300->context.draw_vbo;
126
127 /* Override the draw function. */
128 r300->context.draw_vbo = r300_stencilref_draw_vbo;
129 }
130