diff options
Diffstat (limited to 'mesalib/src/mesa/vbo/vbo_primitive_restart.c')
| -rw-r--r-- | mesalib/src/mesa/vbo/vbo_primitive_restart.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/mesalib/src/mesa/vbo/vbo_primitive_restart.c b/mesalib/src/mesa/vbo/vbo_primitive_restart.c new file mode 100644 index 000000000..18d851c1e --- /dev/null +++ b/mesalib/src/mesa/vbo/vbo_primitive_restart.c @@ -0,0 +1,233 @@ +/* + * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas. + * 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 <jordan.l.justen@intel.com> + * + */ + +#include "main/imports.h" +#include "main/bufferobj.h" +#include "main/macros.h" + +#include "vbo.h" +#include "vbo_context.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 support primitive + * restart itself. (ctx->Const.PrimitiveRestartInSoftware == GL_TRUE) + * + * 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 = (struct sub_primitive *) + 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 prim_num; + 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; + struct _mesa_prim temp_prim; + struct vbo_context *vbo = vbo_context(ctx); + vbo_draw_func draw_prims_func = vbo->draw_prims; + GLboolean map_ib = ib->obj->Name && !ib->obj->Pointer; + void *ptr; + + /* 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); + } + + ptr = ADD_POINTERS(ib->obj->Pointer, ib->ptr); + + sub_prims = find_sub_primitives(ptr, vbo_sizeof_ib_type(ib->type), + 0, ib->count, restart_index, + &num_sub_prims); + + if (map_ib) { + ctx->Driver.UnmapBuffer(ctx, ib->obj); + } + + /* 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)) { + draw_prims_func(ctx, &temp_prim, 1, ib, + GL_TRUE, sub_prim->min_index, sub_prim->max_index, + NULL); + } else { + draw_prims_func(ctx, &temp_prim, 1, ib, + GL_FALSE, -1, -1, + NULL); + } + } + if (sub_end_index >= end_index) { + break; + } + } + } + + if (sub_prims) { + free(sub_prims); + } +} + |