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Diffstat (limited to 'src/mesa/tnl/t_split.c')
| -rw-r--r-- | src/mesa/tnl/t_split.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/src/mesa/tnl/t_split.c b/src/mesa/tnl/t_split.c new file mode 100644 index 00000000000..b98bd404d52 --- /dev/null +++ b/src/mesa/tnl/t_split.c @@ -0,0 +1,160 @@ + +/* + * Mesa 3-D graphics library + * + * Copyright (C) 1999-2006 Brian Paul All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR + * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, + * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + * + * Authors: + * Keith Whitwell <[email protected]> + */ + +/* Deal with hardware and/or swtnl maximums: + * - maximum number of vertices in buffer + * - maximum number of elements (maybe zero) + * + * The maximums may vary with opengl state (eg if a larger hardware + * vertex is required in this state, the maximum number of vertices + * may be smaller than in another state). + * + * We want buffer splitting to be a convenience function for the code + * actually drawing the primitives rather than a system-wide maximum, + * otherwise it is hard to avoid pessimism. + * + * For instance, if a driver has no hardware limits on vertex buffer + * dimensions, it would not ordinarily want to split vbos. But if + * there is an unexpected fallback, eg memory manager fails to upload + * textures, it will want to pass the drawing commands onto swtnl, + * which does have limitations. A convenience function allows swtnl + * to split the drawing and vbos internally without imposing its + * limitations on drivers which want to use it as a fallback path. + */ + +#include "main/glheader.h" +#include "main/mtypes.h" +#include "vbo/vbo.h" + +#include "t_split.h" + + +/* True if a primitive can be split without copying of vertices, false + * otherwise. + */ +GLboolean +_tnl_split_prim_inplace(GLenum mode, GLuint *first, GLuint *incr) +{ + switch (mode) { + case GL_POINTS: + *first = 1; + *incr = 1; + return GL_TRUE; + case GL_LINES: + *first = 2; + *incr = 2; + return GL_TRUE; + case GL_LINE_STRIP: + *first = 2; + *incr = 1; + return GL_TRUE; + case GL_TRIANGLES: + *first = 3; + *incr = 3; + return GL_TRUE; + case GL_TRIANGLE_STRIP: + *first = 3; + *incr = 1; + return GL_TRUE; + case GL_QUADS: + *first = 4; + *incr = 4; + return GL_TRUE; + case GL_QUAD_STRIP: + *first = 4; + *incr = 2; + return GL_TRUE; + default: + *first = 0; + *incr = 1; /* so that count % incr works */ + return GL_FALSE; + } +} + + + +void +_tnl_split_prims(struct gl_context *ctx, + const struct gl_vertex_array arrays[], + const struct _mesa_prim *prim, + GLuint nr_prims, + const struct _mesa_index_buffer *ib, + GLuint min_index, + GLuint max_index, + tnl_draw_func draw, + const struct split_limits *limits) +{ + if (ib) { + if (limits->max_indices == 0) { + /* Could traverse the indices, re-emitting vertices in turn. + * But it's hard to see why this case would be needed - for + * software tnl, it is better to convert to non-indexed + * rendering after transformation is complete. Are there any devices + * with hardware tnl that cannot do indexed rendering? + * + * For now, this path is disabled. + */ + assert(0); + } + else if (max_index - min_index >= limits->max_verts) { + /* The vertex buffers are too large for hardware (or the + * swtnl module). Traverse the indices, re-emitting vertices + * in turn. Use a vertex cache to preserve some of the + * sharing from the original index list. + */ + _tnl_split_copy(ctx, arrays, prim, nr_prims, ib, draw, limits); + } + else if (ib->count > limits->max_indices) { + /* The index buffer is too large for hardware. Try to split + * on whole-primitive boundaries, otherwise try to split the + * individual primitives. + */ + _tnl_split_inplace(ctx, arrays, prim, nr_prims, ib, + min_index, max_index, draw, limits); + } + else { + /* Why were we called? */ + assert(0); + } + } + else { + if (max_index - min_index >= limits->max_verts) { + /* The vertex buffer is too large for hardware (or the swtnl + * module). Try to split on whole-primitive boundaries, + * otherwise try to split the individual primitives. + */ + _tnl_split_inplace(ctx, arrays, prim, nr_prims, ib, + min_index, max_index, draw, limits); + } + else { + /* Why were we called? */ + assert(0); + } + } +} + |