75 lines
1.9 KiB
C++
75 lines
1.9 KiB
C++
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// This file is part of meshoptimizer library; see meshoptimizer.h for version/license details
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#include "meshoptimizer.h"
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#include <assert.h>
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#include <string.h>
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size_t meshopt_optimizeVertexFetchRemap(unsigned int* destination, const unsigned int* indices, size_t index_count, size_t vertex_count)
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{
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assert(index_count % 3 == 0);
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memset(destination, -1, vertex_count * sizeof(unsigned int));
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unsigned int next_vertex = 0;
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for (size_t i = 0; i < index_count; ++i)
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{
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unsigned int index = indices[i];
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assert(index < vertex_count);
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if (destination[index] == ~0u)
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{
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destination[index] = next_vertex++;
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}
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}
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assert(next_vertex <= vertex_count);
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return next_vertex;
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}
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size_t meshopt_optimizeVertexFetch(void* destination, unsigned int* indices, size_t index_count, const void* vertices, size_t vertex_count, size_t vertex_size)
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{
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assert(index_count % 3 == 0);
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assert(vertex_size > 0 && vertex_size <= 256);
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meshopt_Allocator allocator;
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// support in-place optimization
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if (destination == vertices)
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{
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unsigned char* vertices_copy = allocator.allocate<unsigned char>(vertex_count * vertex_size);
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memcpy(vertices_copy, vertices, vertex_count * vertex_size);
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vertices = vertices_copy;
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}
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// build vertex remap table
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unsigned int* vertex_remap = allocator.allocate<unsigned int>(vertex_count);
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memset(vertex_remap, -1, vertex_count * sizeof(unsigned int));
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unsigned int next_vertex = 0;
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for (size_t i = 0; i < index_count; ++i)
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{
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unsigned int index = indices[i];
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assert(index < vertex_count);
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unsigned int& remap = vertex_remap[index];
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if (remap == ~0u) // vertex was not added to destination VB
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{
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// add vertex
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memcpy(static_cast<unsigned char*>(destination) + next_vertex * vertex_size, static_cast<const unsigned char*>(vertices) + index * vertex_size, vertex_size);
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remap = next_vertex++;
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}
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// modify indices in place
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indices[i] = remap;
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}
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assert(next_vertex <= vertex_count);
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return next_vertex;
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}
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