3 * Mesa 3-D graphics library
5 * Copyright (C) 1999-2006 Brian Paul All Rights Reserved.
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
21 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
22 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
23 * OTHER DEALINGS IN THE SOFTWARE.
26 * Keith Whitwell <keithw@vmware.com>
29 /* Helper for drivers which find themselves rendering a range of
30 * indices starting somewhere above zero. Typically the application
31 * is issuing multiple DrawArrays() or DrawElements() to draw
32 * successive primitives layed out linearly in the vertex arrays.
33 * Unless the vertex arrays are all in a VBO, the OpenGL semantics
34 * imply that we need to re-upload the vertex data on each draw call.
35 * In that case, we want to avoid starting the upload at zero, as it
36 * will mean every draw call uploads an increasing amount of not-used
37 * vertex data. Worse - in the software tnl module, all those
38 * vertices will be transformed and lit.
40 * If we just upload the new data, however, the indices will be
41 * incorrect as we tend to upload each set of vertex data to a new
44 * This file provides a helper to adjust the arrays, primitives and
45 * indices of a draw call so that it can be re-issued with a min_index
50 #include "main/bufferobj.h"
51 #include "main/glheader.h"
52 #include "main/imports.h"
53 #include "main/mtypes.h"
58 #define REBASE(TYPE) \
59 static void *rebase_##TYPE( const void *ptr, \
64 const TYPE *in = (TYPE *)ptr; \
65 TYPE *tmp_indices = malloc(count * sizeof(TYPE)); \
67 if (tmp_indices == NULL) { \
68 _mesa_error_no_memory(__func__); \
72 for (i = 0; i < count; i++) \
73 tmp_indices[i] = in[i] - min_index; \
75 return (void *)tmp_indices; \
85 /* Adjust primitives, indices and vertex definitions so that min_index
86 * becomes zero. There are lots of reasons for wanting to do this, eg:
89 * - any time min_index != 0, otherwise unused vertices lower than
90 * min_index will be transformed.
93 * - if ib != NULL and min_index != 0, otherwise vertices lower than
94 * min_index will be uploaded. Requires adjusting index values.
96 * - if ib == NULL and min_index != 0, just for convenience so this doesn't
97 * have to be handled within the driver.
99 * Hardware tnl with VBO support:
100 * - as above, but only when vertices are not (all?) in VBO's.
101 * - can't save time by trying to upload half a vbo - typically it is
104 void t_rebase_prims( struct gl_context
*ctx
,
105 const struct gl_vertex_array
*arrays
,
106 const struct _mesa_prim
*prim
,
108 const struct _mesa_index_buffer
*ib
,
113 struct gl_array_attributes tmp_attribs
[VERT_ATTRIB_MAX
];
114 struct gl_vertex_array tmp_arrays
[VERT_ATTRIB_MAX
];
116 struct _mesa_index_buffer tmp_ib
;
117 struct _mesa_prim
*tmp_prims
= NULL
;
118 const struct gl_vertex_array
*saved_arrays
= ctx
->Array
._DrawArrays
;
119 void *tmp_indices
= NULL
;
122 assert(min_index
!= 0);
125 printf("%s %d..%d\n", __func__
, min_index
, max_index
);
128 /* XXX this path is disabled for now.
129 * There's rendering corruption in some apps when it's enabled.
131 if (0 && ib
&& ctx
->Extensions
.ARB_draw_elements_base_vertex
) {
132 /* If we can just tell the hardware or the TNL to interpret our
133 * indices with a different base, do so.
135 tmp_prims
= malloc(sizeof(*prim
) * nr_prims
);
137 if (tmp_prims
== NULL
) {
138 _mesa_error_no_memory(__func__
);
142 for (i
= 0; i
< nr_prims
; i
++) {
143 tmp_prims
[i
] = prim
[i
];
144 tmp_prims
[i
].basevertex
-= min_index
;
149 /* Unfortunately need to adjust each index individually.
151 GLboolean map_ib
= ib
->obj
->Name
&&
152 !ib
->obj
->Mappings
[MAP_INTERNAL
].Pointer
;
156 ctx
->Driver
.MapBufferRange(ctx
, 0, ib
->obj
->Size
, GL_MAP_READ_BIT
,
157 ib
->obj
, MAP_INTERNAL
);
160 ptr
= ADD_POINTERS(ib
->obj
->Mappings
[MAP_INTERNAL
].Pointer
, ib
->ptr
);
162 /* Some users might prefer it if we translated elements to
163 * GLuints here. Others wouldn't...
165 switch (ib
->index_size
) {
167 tmp_indices
= rebase_GLuint( ptr
, ib
->count
, min_index
);
170 tmp_indices
= rebase_GLushort( ptr
, ib
->count
, min_index
);
173 tmp_indices
= rebase_GLubyte( ptr
, ib
->count
, min_index
);
178 ctx
->Driver
.UnmapBuffer(ctx
, ib
->obj
, MAP_INTERNAL
);
180 if (tmp_indices
== NULL
) {
184 tmp_ib
.obj
= ctx
->Shared
->NullBufferObj
;
185 tmp_ib
.ptr
= tmp_indices
;
186 tmp_ib
.count
= ib
->count
;
187 tmp_ib
.index_size
= ib
->index_size
;
192 /* Otherwise the primitives need adjustment.
194 tmp_prims
= malloc(sizeof(*prim
) * nr_prims
);
196 if (tmp_prims
== NULL
) {
197 _mesa_error_no_memory(__func__
);
201 for (i
= 0; i
< nr_prims
; i
++) {
202 /* If this fails, it could indicate an application error:
204 assert(prim
[i
].start
>= min_index
);
206 tmp_prims
[i
] = prim
[i
];
207 tmp_prims
[i
].start
-= min_index
;
213 /* Just need to adjust the pointer values on each incoming array.
214 * This works for VBO and non-vbo rendering and shouldn't pesimize
215 * VBO-based upload schemes. However this may still not be a fast
216 * path for hardware tnl for VBO based rendering as most machines
217 * will be happier if you just specify a starting vertex value in
220 * For drivers with hardware tnl, you only want to do this if you
221 * are forced to, eg non-VBO indexed rendering with start != 0.
223 for (i
= 0; i
< VERT_ATTRIB_MAX
; i
++) {
224 tmp_attribs
[i
] = *(arrays
[i
].VertexAttrib
);
225 tmp_arrays
[i
].BufferBinding
= arrays
[i
].BufferBinding
;
226 tmp_arrays
[i
].VertexAttrib
= &tmp_attribs
[i
];
227 if (_mesa_is_bufferobj(arrays
[i
].BufferBinding
->BufferObj
))
228 tmp_attribs
[i
].RelativeOffset
+=
229 min_index
* arrays
[i
].BufferBinding
->Stride
;
231 tmp_attribs
[i
].Ptr
+= min_index
* arrays
[i
].BufferBinding
->Stride
;
234 /* Re-issue the draw call.
236 ctx
->Array
._DrawArrays
= tmp_arrays
;
237 ctx
->NewDriverState
|= ctx
->DriverFlags
.NewArray
;
245 max_index
- min_index
,
248 ctx
->Array
._DrawArrays
= saved_arrays
;
249 ctx
->NewDriverState
|= ctx
->DriverFlags
.NewArray
;