/* * 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> */ /* Helper for drivers which find themselves rendering a range of * indices starting somewhere above zero. Typically the application * is issuing multiple DrawArrays() or DrawElements() to draw * successive primitives layed out linearly in the vertex arrays. * Unless the vertex arrays are all in a VBO, the OpenGL semantics * imply that we need to re-upload the vertex data on each draw call. * In that case, we want to avoid starting the upload at zero, as it * will mean every draw call uploads an increasing amount of not-used * vertex data. Worse - in the software tnl module, all those * vertices will be transformed and lit. * * If we just upload the new data, however, the indices will be * incorrect as we tend to upload each set of vertex data to a new * region. * * This file provides a helper to adjust the arrays, primitives and * indices of a draw call so that it can be re-issued with a min_index * of zero. */ #include "main/glheader.h" #include "main/imports.h" #include "main/mtypes.h" #include "vbo.h" #define REBASE(TYPE) \ static void *rebase_##TYPE( const void *ptr, \ GLuint count, \ TYPE min_index ) \ { \ const TYPE *in = (TYPE *)ptr; \ TYPE *tmp_indices = malloc(count * sizeof(TYPE)); \ GLuint i; \ \ for (i = 0; i < count; i++) \ tmp_indices[i] = in[i] - min_index; \ \ return (void *)tmp_indices; \ } REBASE(GLuint) REBASE(GLushort) REBASE(GLubyte) GLboolean vbo_all_varyings_in_vbos( const struct gl_client_array *arrays[] ) { GLuint i; for (i = 0; i < VERT_ATTRIB_MAX; i++) if (arrays[i]->StrideB && arrays[i]->BufferObj->Name == 0) return GL_FALSE; return GL_TRUE; } GLboolean vbo_any_varyings_in_vbos( const struct gl_client_array *arrays[] ) { GLuint i; for (i = 0; i < VERT_ATTRIB_MAX; i++) if (arrays[i]->BufferObj->Name != 0) return GL_TRUE; return GL_FALSE; } /* Adjust primitives, indices and vertex definitions so that min_index * becomes zero. There are lots of reasons for wanting to do this, eg: * * Software tnl: * - any time min_index != 0, otherwise unused vertices lower than * min_index will be transformed. * * Hardware tnl: * - if ib != NULL and min_index != 0, otherwise vertices lower than * min_index will be uploaded. Requires adjusting index values. * * - if ib == NULL and min_index != 0, just for convenience so this doesn't * have to be handled within the driver. * * Hardware tnl with VBO support: * - as above, but only when vertices are not (all?) in VBO's. * - can't save time by trying to upload half a vbo - typically it is * all or nothing. */ void vbo_rebase_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 ) { struct gl_client_array tmp_arrays[VERT_ATTRIB_MAX]; const struct gl_client_array *tmp_array_pointers[VERT_ATTRIB_MAX]; struct _mesa_index_buffer tmp_ib; struct _mesa_prim *tmp_prims = NULL; void *tmp_indices = NULL; GLuint i; assert(min_index != 0); if (0) printf("%s %d..%d\n", __FUNCTION__, min_index, max_index); /* XXX this path is disabled for now. * There's rendering corruption in some apps when it's enabled. */ if (0 && ib && ctx->Extensions.ARB_draw_elements_base_vertex) { /* If we can just tell the hardware or the TNL to interpret our * indices with a different base, do so. */ tmp_prims = (struct _mesa_prim *)malloc(sizeof(*prim) * nr_prims); for (i = 0; i < nr_prims; i++) { tmp_prims[i] = prim[i]; tmp_prims[i].basevertex -= min_index; } prim = tmp_prims; } else if (ib) { /* Unfortunately need to adjust each index individually. */ GLboolean map_ib = ib->obj->Name && !ib->obj->Pointer; void *ptr; if (map_ib) ctx->Driver.MapBufferRange(ctx, 0, ib->obj->Size, GL_MAP_READ_BIT, ib->obj); ptr = ADD_POINTERS(ib->obj->Pointer, ib->ptr); /* Some users might prefer it if we translated elements to * GLuints here. Others wouldn't... */ switch (ib->type) { case GL_UNSIGNED_INT: tmp_indices = rebase_GLuint( ptr, ib->count, min_index ); break; case GL_UNSIGNED_SHORT: tmp_indices = rebase_GLushort( ptr, ib->count, min_index ); break; case GL_UNSIGNED_BYTE: tmp_indices = rebase_GLubyte( ptr, ib->count, min_index ); break; } if (map_ib) ctx->Driver.UnmapBuffer(ctx, ib->obj); tmp_ib.obj = ctx->Shared->NullBufferObj; tmp_ib.ptr = tmp_indices; tmp_ib.count = ib->count; tmp_ib.type = ib->type; ib = &tmp_ib; } else { /* Otherwise the primitives need adjustment. */ tmp_prims = (struct _mesa_prim *)malloc(sizeof(*prim) * nr_prims); for (i = 0; i < nr_prims; i++) { /* If this fails, it could indicate an application error: */ assert(prim[i].start >= min_index); tmp_prims[i] = prim[i]; tmp_prims[i].start -= min_index; } prim = tmp_prims; } /* Just need to adjust the pointer values on each incoming array. * This works for VBO and non-vbo rendering and shouldn't pesimize * VBO-based upload schemes. However this may still not be a fast * path for hardware tnl for VBO based rendering as most machines * will be happier if you just specify a starting vertex value in * each primitive. * * For drivers with hardware tnl, you only want to do this if you * are forced to, eg non-VBO indexed rendering with start != 0. */ for (i = 0; i < VERT_ATTRIB_MAX; i++) { tmp_arrays[i] = *arrays[i]; tmp_arrays[i].Ptr += min_index * tmp_arrays[i].StrideB; tmp_array_pointers[i] = &tmp_arrays[i]; } /* Re-issue the draw call. */ draw( ctx, tmp_array_pointers, prim, nr_prims, ib, GL_TRUE, 0, max_index - min_index, NULL ); if (tmp_indices) free(tmp_indices); if (tmp_prims) free(tmp_prims); }