1 /*
2  * Copyright 2009 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 "Software"),
7  * to deal in the Software without restriction, including without limitation
8  * on the rights to use, copy, modify, merge, publish, distribute, sub
9  * license, and/or sell copies of the Software, and to permit persons to whom
10  * the Software is furnished to do so, subject to the following conditions:
11  *
12  * The above copyright notice and this permission notice (including the next
13  * paragraph) shall be included in all copies or substantial portions of the
14  * Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
19  * VMWARE AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
20  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
21  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
22  * USE OR OTHER DEALINGS IN THE SOFTWARE.
23  */
24 
25 #ifndef U_INDICES_H
26 #define U_INDICES_H
27 
28 #include "pipe/p_compiler.h"
29 #include "pipe/p_defines.h"
30 
31 /* First/last provoking vertex */
32 #define PV_FIRST      0
33 #define PV_LAST       1
34 #define PV_COUNT      2
35 
36 /* primitive restart disable/enable flags */
37 #define PR_DISABLE 0
38 #define PR_ENABLE 1
39 #define PR_COUNT 2
40 
41 
42 /**
43  * Index translator function (for glDrawElements() case)
44  *
45  * \param in     the input index buffer
46  * \param start  the index of the first vertex (pipe_draw_info::start)
47  * \param nr     the number of vertices (pipe_draw_info::count)
48  * \param out    output buffer big enough for nr vertices (of
49  *    @out_index_size bytes each)
50  */
51 typedef void (*u_translate_func)( const void *in,
52                                   unsigned start,
53                                   unsigned in_nr,
54                                   unsigned out_nr,
55                                   unsigned restart_index,
56                                   void *out );
57 
58 /**
59  * Index generator function (for glDrawArrays() case)
60  *
61  * \param start  the index of the first vertex (pipe_draw_info::start)
62  * \param nr     the number of vertices (pipe_draw_info::count)
63  * \param out    output buffer big enough for nr vertices (of
64  *    @out_index_size bytes each)
65  */
66 typedef void (*u_generate_func)( unsigned start,
67                                  unsigned nr,
68                                  void *out );
69 
70 
71 /* Return codes describe the translate/generate operation.  Caller may
72  * be able to reuse translated indices under some circumstances.
73  */
74 enum indices_mode {
75    U_TRANSLATE_ERROR = -1,
76    U_TRANSLATE_NORMAL = 1,
77    U_TRANSLATE_MEMCPY = 2,
78    U_GENERATE_LINEAR  = 3,
79    U_GENERATE_REUSABLE= 4,
80    U_GENERATE_ONE_OFF = 5,
81 };
82 
83 void u_index_init( void );
84 
85 /* returns the primitive type resulting from index translation */
86 enum pipe_prim_type
87 u_index_prim_type_convert(unsigned hw_mask, enum pipe_prim_type prim, bool pv_matches);
88 
89 static inline unsigned
u_index_size_convert(unsigned index_size)90 u_index_size_convert(unsigned index_size)
91 {
92    return (index_size == 4) ? 4 : 2;
93 }
94 
95 unsigned
96 u_index_count_converted_indices(unsigned hw_mask, bool pv_matches, enum pipe_prim_type prim, unsigned nr);
97 
98 /**
99  * For indexed drawing, this function determines what kind of primitive
100  * transformation is needed (if any) for handling:
101  * - unsupported primitive types (such as PIPE_PRIM_POLYGON)
102  * - changing the provoking vertex
103  * - primitive restart
104  * - index size (1 byte, 2 byte or 4 byte indexes)
105  */
106 enum indices_mode
107 u_index_translator(unsigned hw_mask,
108                    enum pipe_prim_type prim,
109                    unsigned in_index_size,
110                    unsigned nr,
111                    unsigned in_pv,   /* API */
112                    unsigned out_pv,  /* hardware */
113                    unsigned prim_restart,
114                    enum pipe_prim_type *out_prim,
115                    unsigned *out_index_size,
116                    unsigned *out_nr,
117                    u_translate_func *out_translate);
118 
119 
120 /**
121  * For non-indexed drawing, this function determines what kind of primitive
122  * transformation is needed (see above).
123  *
124  * Note that even when generating it is necessary to know what the
125  * API's PV is, as the indices generated will depend on whether it is
126  * the same as hardware or not, and in the case of triangle strips,
127  * whether it is first or last.
128  */
129 enum indices_mode
130 u_index_generator(unsigned hw_mask,
131                   enum pipe_prim_type prim,
132                   unsigned start,
133                   unsigned nr,
134                   unsigned in_pv,   /* API */
135                   unsigned out_pv,  /* hardware */
136                   enum pipe_prim_type *out_prim,
137                   unsigned *out_index_size,
138                   unsigned *out_nr,
139                   u_generate_func *out_generate);
140 
141 
142 void u_unfilled_init( void );
143 
144 /**
145  * If the driver can't handle "unfilled" primitives (i.e. drawing triangle
146  * primitives as 3 lines or 3 points) this function can be used to translate
147  * an indexed primitive into a new indexed primitive to draw as lines or
148  * points.
149  */
150 enum indices_mode
151 u_unfilled_translator(enum pipe_prim_type prim,
152                       unsigned in_index_size,
153                       unsigned nr,
154                       unsigned unfilled_mode,
155                       enum pipe_prim_type *out_prim,
156                       unsigned *out_index_size,
157                       unsigned *out_nr,
158                       u_translate_func *out_translate);
159 
160 /**
161  * As above, but for non-indexed (array) primitives.
162  */
163 enum indices_mode
164 u_unfilled_generator(enum pipe_prim_type prim,
165                      unsigned start,
166                      unsigned nr,
167                      unsigned unfilled_mode,
168                      enum pipe_prim_type *out_prim,
169                      unsigned *out_index_size,
170                      unsigned *out_nr,
171                      u_generate_func *out_generate);
172 
173 #endif
174