1 /*
2 * Copyright 2018 VMware, Inc.
3 * All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the
7 * "Software"), to deal in the Software without restriction, including
8 * without limitation the rights to use, copy, modify, merge, publish,
9 * distribute, sub license, and/or sell copies of the Software, and to
10 * permit persons to whom the Software is furnished to do so, subject to
11 * the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the
14 * next paragraph) shall be included in all copies or substantial portions
15 * of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
20 * IN NO EVENT SHALL THE AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR
21 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
22 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
23 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24 */
25
26
27 /**
28 * TGSI utility transforms the shader to write imm(0, 0, 0, 1) to vertex
29 * position
30 */
31
32 #include "util/u_debug.h"
33 #include "util/u_math.h"
34 #include "tgsi_vpos.h"
35 #include "tgsi_transform.h"
36 #include "tgsi_dump.h"
37 #include "pipe/p_state.h"
38
39
40 struct write_vpos_context
41 {
42 struct tgsi_transform_context base;
43 unsigned imm_index;
44 };
45
46
47 static inline struct write_vpos_context *
write_vpos_context(struct tgsi_transform_context * ctx)48 write_vpos_context(struct tgsi_transform_context *ctx)
49 {
50 return (struct write_vpos_context *) ctx;
51 }
52
53
54 /**
55 * TGSI transform prolog callback.
56 */
57 static void
write_vpos_prolog(struct tgsi_transform_context * ctx)58 write_vpos_prolog(struct tgsi_transform_context *ctx)
59 {
60 struct write_vpos_context *vc = write_vpos_context(ctx);
61 struct tgsi_full_instruction inst;
62
63 tgsi_transform_immediate_decl(ctx, 0.0, 0.0, 0.0, 1.0);
64 tgsi_transform_output_decl(ctx, 0,
65 TGSI_SEMANTIC_POSITION, 0,
66 0);
67 inst = tgsi_default_full_instruction();
68 inst.Instruction.Opcode = TGSI_OPCODE_MOV;
69 inst.Instruction.NumDstRegs = 1;
70 tgsi_transform_dst_reg(&inst.Dst[0], TGSI_FILE_OUTPUT,
71 0, TGSI_WRITEMASK_XYZW);
72 inst.Instruction.NumSrcRegs = 1;
73 tgsi_transform_src_reg(&inst.Src[0], TGSI_FILE_IMMEDIATE,
74 vc->imm_index, TGSI_SWIZZLE_X,
75 TGSI_SWIZZLE_Y, TGSI_SWIZZLE_Z, TGSI_SWIZZLE_W);
76 ctx->emit_instruction(ctx, &inst);
77 }
78
79
80 /**
81 * TGSI utility writes imm(0, 0, 0, 1) to vertex position
82 */
83 struct tgsi_token *
tgsi_write_vpos(const struct tgsi_token * tokens_in,unsigned num_immediates)84 tgsi_write_vpos(const struct tgsi_token *tokens_in,
85 unsigned num_immediates)
86 {
87 struct write_vpos_context transform;
88 const uint num_new_tokens = 1000; /* should be enough */
89 const uint new_len = tgsi_num_tokens(tokens_in) + num_new_tokens;
90 struct tgsi_token *new_tokens;
91
92 /* setup transformation context */
93 memset(&transform, 0, sizeof(transform));
94 transform.base.prolog = write_vpos_prolog;
95
96 transform.imm_index = num_immediates;
97
98 /* allocate new tokens buffer */
99 new_tokens = tgsi_alloc_tokens(new_len);
100 if (!new_tokens)
101 return NULL;
102
103 /* transform the shader */
104 tgsi_transform_shader(tokens_in, new_tokens, new_len, &transform.base);
105
106 return new_tokens;
107 }
108
109
110