/* * Copyright 2007 VMware, Inc. * All Rights Reserved. * * Copyright © 2012 Intel Corporation * * 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 (including the next * paragraph) 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: * Jordan Justen * */ #include "main/errors.h" #include "util/imports.h" #include "main/macros.h" #include "main/varray.h" #include "vbo.h" #define UPDATE_MIN2(a, b) (a) = MIN2((a), (b)) #define UPDATE_MAX2(a, b) (a) = MAX2((a), (b)) /* * Notes on primitive restart: * The code below is used when the driver does not fully support primitive * restart (for example, if it only does restart index of ~0). * * We map the index buffer, find the restart indexes, unmap * the index buffer then draw the sub-primitives delineated by the restarts. * * A couple possible optimizations: * 1. Save the list of sub-primitive (start, count) values in a list attached * to the index buffer for re-use in subsequent draws. The list would be * invalidated when the contents of the buffer changed. * 2. If drawing triangle strips or quad strips, create a new index buffer * that uses duplicated vertices to render the disjoint strips as one * long strip. We'd have to be careful to avoid using too much memory * for this. * * Finally, some apps might perform better if they don't use primitive restart * at all rather than this fallback path. Set MESA_EXTENSION_OVERRIDE to * "-GL_NV_primitive_restart" to test that. */ struct sub_primitive { GLuint start; GLuint count; GLuint min_index; GLuint max_index; }; /** * Scan the elements array to find restart indexes. Return an array * of struct sub_primitive to indicate how to draw the sub-primitives * are delineated by the restart index. */ static struct sub_primitive * find_sub_primitives(const void *elements, unsigned element_size, unsigned start, unsigned end, unsigned restart_index, unsigned *num_sub_prims) { const unsigned max_prims = end - start; struct sub_primitive *sub_prims; unsigned i, cur_start, cur_count; GLuint scan_index; unsigned scan_num; sub_prims = malloc(max_prims * sizeof(struct sub_primitive)); if (!sub_prims) { *num_sub_prims = 0; return NULL; } cur_start = start; cur_count = 0; scan_num = 0; #define IB_INDEX_READ(TYPE, INDEX) (((const GL##TYPE *) elements)[INDEX]) #define SCAN_ELEMENTS(TYPE) \ sub_prims[scan_num].min_index = (GL##TYPE) 0xffffffff; \ sub_prims[scan_num].max_index = 0; \ for (i = start; i < end; i++) { \ scan_index = IB_INDEX_READ(TYPE, i); \ if (scan_index == restart_index) { \ if (cur_count > 0) { \ assert(scan_num < max_prims); \ sub_prims[scan_num].start = cur_start; \ sub_prims[scan_num].count = cur_count; \ scan_num++; \ sub_prims[scan_num].min_index = (GL##TYPE) 0xffffffff; \ sub_prims[scan_num].max_index = 0; \ } \ cur_start = i + 1; \ cur_count = 0; \ } \ else { \ UPDATE_MIN2(sub_prims[scan_num].min_index, scan_index); \ UPDATE_MAX2(sub_prims[scan_num].max_index, scan_index); \ cur_count++; \ } \ } \ if (cur_count > 0) { \ assert(scan_num < max_prims); \ sub_prims[scan_num].start = cur_start; \ sub_prims[scan_num].count = cur_count; \ scan_num++; \ } switch (element_size) { case 1: SCAN_ELEMENTS(ubyte); break; case 2: SCAN_ELEMENTS(ushort); break; case 4: SCAN_ELEMENTS(uint); break; default: assert(0 && "bad index_size in find_sub_primitives()"); } #undef SCAN_ELEMENTS *num_sub_prims = scan_num; return sub_prims; } /** * Handle primitive restart in software. * * This function breaks up calls into the driver so primitive restart * support is not required in the driver. */ void vbo_sw_primitive_restart(struct gl_context *ctx, const struct _mesa_prim *prims, GLuint nr_prims, const struct _mesa_index_buffer *ib, GLuint num_instances, GLuint base_instance, struct gl_buffer_object *indirect, GLsizeiptr indirect_offset) { GLuint prim_num; struct _mesa_prim new_prim; struct _mesa_index_buffer new_ib; struct sub_primitive *sub_prims; struct sub_primitive *sub_prim; GLuint num_sub_prims; GLuint sub_prim_num; GLuint end_index; GLuint sub_end_index; GLuint restart_index = ctx->Array._RestartIndex[(1 << ib->index_size_shift) - 1]; struct _mesa_prim temp_prim; GLboolean map_ib = ib->obj && !ib->obj->Mappings[MAP_INTERNAL].Pointer; const void *ptr; /* If there is an indirect buffer, map it and extract the draw params */ if (indirect) { const uint32_t *indirect_params; if (!ctx->Driver.MapBufferRange(ctx, 0, indirect->Size, GL_MAP_READ_BIT, indirect, MAP_INTERNAL)) { /* something went wrong with mapping, give up */ _mesa_error(ctx, GL_OUT_OF_MEMORY, "failed to map indirect buffer for sw primitive restart"); return; } assert(nr_prims == 1); new_prim = prims[0]; indirect_params = (const uint32_t *) ADD_POINTERS(indirect->Mappings[MAP_INTERNAL].Pointer, indirect_offset); new_prim.count = indirect_params[0]; new_prim.start = indirect_params[2]; new_prim.basevertex = indirect_params[3]; num_instances = indirect_params[1]; base_instance = indirect_params[4]; new_ib = *ib; new_ib.count = new_prim.count; prims = &new_prim; ib = &new_ib; ctx->Driver.UnmapBuffer(ctx, indirect, MAP_INTERNAL); } /* Find the sub-primitives. These are regions in the index buffer which * are split based on the primitive restart index value. */ if (map_ib) { ctx->Driver.MapBufferRange(ctx, 0, ib->obj->Size, GL_MAP_READ_BIT, ib->obj, MAP_INTERNAL); } if (ib->obj) ptr = ADD_POINTERS(ib->obj->Mappings[MAP_INTERNAL].Pointer, ib->ptr); else ptr = ib->ptr; sub_prims = find_sub_primitives(ptr, 1 << ib->index_size_shift, 0, ib->count, restart_index, &num_sub_prims); if (map_ib) { ctx->Driver.UnmapBuffer(ctx, ib->obj, MAP_INTERNAL); } /* Loop over the primitives, and use the located sub-primitives to draw * each primitive with a break to implement each primitive restart. */ for (prim_num = 0; prim_num < nr_prims; prim_num++) { end_index = prims[prim_num].start + prims[prim_num].count; memcpy(&temp_prim, &prims[prim_num], sizeof (temp_prim)); /* Loop over the sub-primitives drawing sub-ranges of the primitive. */ for (sub_prim_num = 0; sub_prim_num < num_sub_prims; sub_prim_num++) { sub_prim = &sub_prims[sub_prim_num]; sub_end_index = sub_prim->start + sub_prim->count; if (prims[prim_num].start <= sub_prim->start) { temp_prim.start = MAX2(prims[prim_num].start, sub_prim->start); temp_prim.count = MIN2(sub_end_index, end_index) - temp_prim.start; if ((temp_prim.start == sub_prim->start) && (temp_prim.count == sub_prim->count)) { ctx->Driver.Draw(ctx, &temp_prim, 1, ib, GL_TRUE, sub_prim->min_index, sub_prim->max_index, num_instances, base_instance, NULL, 0); } else { ctx->Driver.Draw(ctx, &temp_prim, 1, ib, GL_FALSE, -1, -1, num_instances, base_instance, NULL, 0); } } if (sub_end_index >= end_index) { break; } } } free(sub_prims); }