1/**************************************************************************
2 *
3 * Copyright 2009 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 * @file
30 * Position and shader input interpolation.
31 *
32 * Special attention is given to the interpolation of side by side quads.
33 * Multiplications are made only for the first quad. Interpolation of
34 * inputs for posterior quads are done exclusively with additions, and
35 * perspective divide if necessary.
36 *
37 * @author Jose Fonseca <jfonseca@vmware.com>
38 */
39
40#ifndef LP_BLD_INTERP_H
41#define LP_BLD_INTERP_H
42
43
44#include "gallivm/lp_bld.h"
45#include "gallivm/lp_bld_type.h"
46
47#include "tgsi/tgsi_exec.h"
48
49/**
50 * Describes how to compute the interpolation coefficients (a0, dadx, dady)
51 * from the vertices passed into our triangle/line/point functions by the
52 * draw module.
53 *
54 * Vertices are treated as an array of float[4] values, indexed by
55 * src_index.
56 *
57 * LP_INTERP_COLOR is translated to either LP_INTERP_CONSTANT or
58 * PERSPECTIVE depending on flatshade state.
59 */
60enum lp_interp {
61   LP_INTERP_CONSTANT,
62   LP_INTERP_COLOR,
63   LP_INTERP_LINEAR,
64   LP_INTERP_PERSPECTIVE,
65   LP_INTERP_POSITION,
66   LP_INTERP_FACING
67};
68
69struct lp_shader_input {
70   uint interp:4;       /* enum lp_interp */
71   uint usage_mask:4;   /* bitmask of TGSI_WRITEMASK_x flags */
72   uint src_index:8;    /* where to find values in incoming vertices */
73   uint cyl_wrap:4;     /* TGSI_CYLINDRICAL_WRAP_x flags */
74   uint padding:12;
75};
76
77
78struct lp_build_interp_soa_context
79{
80   /* TGSI_QUAD_SIZE x float */
81   struct lp_build_context coeff_bld;
82   struct lp_build_context setup_bld;
83
84   unsigned num_attribs;
85   unsigned mask[1 + PIPE_MAX_SHADER_INPUTS]; /**< TGSI_WRITE_MASK_x */
86   enum lp_interp interp[1 + PIPE_MAX_SHADER_INPUTS];
87   boolean simple_interp;
88   boolean dynamic_offsets;
89
90   LLVMValueRef x;
91   LLVMValueRef y;
92
93   LLVMValueRef a[1 + PIPE_MAX_SHADER_INPUTS][TGSI_NUM_CHANNELS];
94   LLVMValueRef dadq[1 + PIPE_MAX_SHADER_INPUTS][TGSI_NUM_CHANNELS];
95   LLVMValueRef a0aos[1 + PIPE_MAX_SHADER_INPUTS];
96   LLVMValueRef dadxaos[1 + PIPE_MAX_SHADER_INPUTS];
97   LLVMValueRef dadyaos[1 + PIPE_MAX_SHADER_INPUTS];
98
99   LLVMValueRef oow;
100
101   LLVMValueRef attribs[1 + PIPE_MAX_SHADER_INPUTS][TGSI_NUM_CHANNELS];
102
103   LLVMValueRef xoffset_store;
104   LLVMValueRef yoffset_store;
105
106   /*
107    * Convenience pointers. Callers may access this one.
108    */
109   const LLVMValueRef *pos;
110   const LLVMValueRef (*inputs)[TGSI_NUM_CHANNELS];
111};
112
113
114void
115lp_build_interp_soa_init(struct lp_build_interp_soa_context *bld,
116                         struct gallivm_state *gallivm,
117                         unsigned num_inputs,
118                         const struct lp_shader_input *inputs,
119                         LLVMBuilderRef builder,
120                         struct lp_type type,
121                         boolean dynamic_offsets,
122                         LLVMValueRef a0_ptr,
123                         LLVMValueRef dadx_ptr,
124                         LLVMValueRef dady_ptr,
125                         LLVMValueRef x,
126                         LLVMValueRef y);
127
128void
129lp_build_interp_soa_update_inputs(struct lp_build_interp_soa_context *bld,
130                                  struct gallivm_state *gallivm,
131                                  int quad_start_index);
132
133void
134lp_build_interp_soa_update_pos(struct lp_build_interp_soa_context *bld,
135                               struct gallivm_state *gallivm,
136                               int quad__start_index);
137
138void
139lp_build_interp_soa_update_inputs_dyn(struct lp_build_interp_soa_context *bld,
140                                      struct gallivm_state *gallivm,
141                                      LLVMValueRef quad_start_index);
142
143void
144lp_build_interp_soa_update_pos_dyn(struct lp_build_interp_soa_context *bld,
145                                   struct gallivm_state *gallivm,
146                                   LLVMValueRef quad_start_index);
147
148#endif /* LP_BLD_INTERP_H */
149