/* * Mesa 3-D graphics library * Version: 6.5 * * 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 * BRIAN PAUL 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 <keith@tungstengraphics.com> */ /* 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/imports.h" #include "main/mtypes.h" #include "main/macros.h" #include "vbo_split.h" #include "vbo.h" /* True if a primitive can be split without copying of vertices, false * otherwise. */ GLboolean 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 vbo_split_prims( struct gl_context *ctx, const struct gl_client_array *arrays[], const struct _mesa_prim *prim, GLuint nr_prims, const struct _mesa_index_buffer *ib, GLuint min_index, GLuint max_index, vbo_draw_func draw, const struct split_limits *limits ) { GLint max_basevertex = prim->basevertex; GLuint i; for (i = 1; i < nr_prims; i++) max_basevertex = MAX2(max_basevertex, prim[i].basevertex); /* XXX max_basevertex is computed but not used, why? */ 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, as is done in * the t_dd_rendertmp.h templates. 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. */ vbo_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. */ vbo_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. */ vbo_split_inplace(ctx, arrays, prim, nr_prims, ib, min_index, max_index, draw, limits ); } else { /* Why were we called? */ assert(0); } } }