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 pipe_draw_func draw_vbo;
38
39 uint32_t rs_cull_mode;
40 uint32_t zb_stencilrefmask;
41 uint8_t ref_value_front;
42 };
43
r300_stencilref_needed(struct r300_context * r300)44 static bool r300_stencilref_needed(struct r300_context *r300)
45 {
46 struct r300_dsa_state *dsa = (struct r300_dsa_state*)r300->dsa_state.state;
47
48 return dsa->two_sided_stencil_ref ||
49 (dsa->two_sided &&
50 r300->stencil_ref.ref_value[0] != r300->stencil_ref.ref_value[1]);
51 }
52
53 /* Set drawing for front faces. */
r300_stencilref_begin(struct r300_context * r300)54 static void r300_stencilref_begin(struct r300_context *r300)
55 {
56 struct r300_stencilref_context *sr = r300->stencilref_fallback;
57 struct r300_rs_state *rs = (struct r300_rs_state*)r300->rs_state.state;
58 struct r300_dsa_state *dsa = (struct r300_dsa_state*)r300->dsa_state.state;
59
60 /* Save state. */
61 sr->rs_cull_mode = rs->cb_main[rs->cull_mode_index];
62 sr->zb_stencilrefmask = dsa->stencil_ref_mask;
63 sr->ref_value_front = r300->stencil_ref.ref_value[0];
64
65 /* We *cull* pixels, therefore no need to mask out the bits. */
66 rs->cb_main[rs->cull_mode_index] |= R300_CULL_BACK;
67
68 r300_mark_atom_dirty(r300, &r300->rs_state);
69 }
70
71 /* Set drawing for back faces. */
r300_stencilref_switch_side(struct r300_context * r300)72 static void r300_stencilref_switch_side(struct r300_context *r300)
73 {
74 struct r300_stencilref_context *sr = r300->stencilref_fallback;
75 struct r300_rs_state *rs = (struct r300_rs_state*)r300->rs_state.state;
76 struct r300_dsa_state *dsa = (struct r300_dsa_state*)r300->dsa_state.state;
77
78 rs->cb_main[rs->cull_mode_index] = sr->rs_cull_mode | R300_CULL_FRONT;
79 dsa->stencil_ref_mask = dsa->stencil_ref_bf;
80 r300->stencil_ref.ref_value[0] = r300->stencil_ref.ref_value[1];
81
82 r300_mark_atom_dirty(r300, &r300->rs_state);
83 r300_mark_atom_dirty(r300, &r300->dsa_state);
84 }
85
86 /* Restore the original state. */
r300_stencilref_end(struct r300_context * r300)87 static void r300_stencilref_end(struct r300_context *r300)
88 {
89 struct r300_stencilref_context *sr = r300->stencilref_fallback;
90 struct r300_rs_state *rs = (struct r300_rs_state*)r300->rs_state.state;
91 struct r300_dsa_state *dsa = (struct r300_dsa_state*)r300->dsa_state.state;
92
93 /* Restore state. */
94 rs->cb_main[rs->cull_mode_index] = sr->rs_cull_mode;
95 dsa->stencil_ref_mask = sr->zb_stencilrefmask;
96 r300->stencil_ref.ref_value[0] = sr->ref_value_front;
97
98 r300_mark_atom_dirty(r300, &r300->rs_state);
99 r300_mark_atom_dirty(r300, &r300->dsa_state);
100 }
101
r300_stencilref_draw_vbo(struct pipe_context * pipe,const struct pipe_draw_info * info,unsigned drawid_offset,const struct pipe_draw_indirect_info * indirect,const struct pipe_draw_start_count_bias * draws,unsigned num_draws)102 static void r300_stencilref_draw_vbo(struct pipe_context *pipe,
103 const struct pipe_draw_info *info,
104 unsigned drawid_offset,
105 const struct pipe_draw_indirect_info *indirect,
106 const struct pipe_draw_start_count_bias *draws,
107 unsigned num_draws)
108 {
109 struct r300_context *r300 = r300_context(pipe);
110 struct r300_stencilref_context *sr = r300->stencilref_fallback;
111
112 if (!r300_stencilref_needed(r300)) {
113 sr->draw_vbo(pipe, info, drawid_offset, NULL, draws, num_draws);
114 } else {
115 r300_stencilref_begin(r300);
116 sr->draw_vbo(pipe, info, drawid_offset, NULL, draws, num_draws);
117 r300_stencilref_switch_side(r300);
118 sr->draw_vbo(pipe, info, drawid_offset, NULL, draws, num_draws);
119 r300_stencilref_end(r300);
120 }
121 }
122
r300_plug_in_stencil_ref_fallback(struct r300_context * r300)123 void r300_plug_in_stencil_ref_fallback(struct r300_context *r300)
124 {
125 r300->stencilref_fallback = CALLOC_STRUCT(r300_stencilref_context);
126
127 /* Save original draw function. */
128 r300->stencilref_fallback->draw_vbo = r300->context.draw_vbo;
129
130 /* Override the draw function. */
131 r300->context.draw_vbo = r300_stencilref_draw_vbo;
132 }
133