53 lines
1.7 KiB
C++
53 lines
1.7 KiB
C++
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#define CGLTF_IMPLEMENTATION
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#include "../cgltf.h"
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// Performs matrix-vector multiplication, as in (4x4) * (4x1) = (4x1)
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static void transform(const cgltf_float matrix[16], const cgltf_float source[4], cgltf_float target[4]) {
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target[0] = matrix[0] * source[0] + matrix[4] * source[1] + matrix[ 8] * source[2] + matrix[12] * source[3];
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target[1] = matrix[1] * source[0] + matrix[5] * source[1] + matrix[ 9] * source[2] + matrix[13] * source[3];
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target[2] = matrix[2] * source[0] + matrix[6] * source[1] + matrix[10] * source[2] + matrix[14] * source[3];
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target[3] = matrix[3] * source[0] + matrix[7] * source[1] + matrix[11] * source[2] + matrix[15] * source[3];
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}
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static void set(cgltf_float target[3], float x, float y, float z) {
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target[0] = x;
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target[1] = y;
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target[2] = z;
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}
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static void check(cgltf_float target[3], float x, float y, float z) {
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if (target[0] != x || target[1] != y || target[2] != z) {
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fprintf(stderr, "Mismatch detected.\n");
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exit(1);
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}
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}
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int main(int, char**)
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{
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cgltf_node node = {};
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cgltf_float matrix[16];
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cgltf_float source[4] = {1, 2, 3, 1};
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cgltf_float target[4];
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set(node.scale, 1, 1, 1);
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set(node.translation, 1, 0, 0);
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cgltf_node_transform_local(&node, matrix);
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transform(matrix, source, target);
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check(target, 2, 2, 3);
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set(node.scale, 3, 1, 1);
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set(node.translation, 0, 0, 0);
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cgltf_node_transform_local(&node, matrix);
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transform(matrix, source, target);
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check(target, 3, 2, 3);
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set(node.scale, 1, 3, 1);
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set(node.translation, 1, 0, 0);
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cgltf_node_transform_local(&node, matrix);
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transform(matrix, source, target);
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check(target, 2, 6, 3);
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return 0;
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}
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