45 lines
1.8 KiB
C
45 lines
1.8 KiB
C
#ifndef GEOMETRY_UTILITIES_H
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#define GEOMETRY_UTILITIES_H
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#include "Triangle.h"
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inline void quad_create(vec3s center, vec3s forward, vec3s up, float size, uint8_t material_id, triangle_collection_t* collection)
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{
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float half_size = size / 2.0f;
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vec3s right = glms_vec3_cross(forward, up);
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vec3s scaled_right = glms_vec3_scale(right, half_size);
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vec3s scaled_up = glms_vec3_scale(up, half_size);
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vec3s temp_sub = glms_vec3_sub(center, scaled_right);
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vec3s temp_add = glms_vec3_add(center, scaled_right);
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vec3s top_left = glms_vec3_add(temp_sub, scaled_up);
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vec3s top_right = glms_vec3_add(temp_add, scaled_up);
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vec3s bottom_right = glms_vec3_sub(temp_add, scaled_up);
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vec3s bottom_left = glms_vec3_sub(temp_sub, scaled_up);
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vec2s uv0 = {0.0f, 0.0f};
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vec2s uv1 = {1.0f, 0.0f};
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vec2s uv2 = {1.0f, 1.0f};
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vec2s uv3 = {0.0f, 1.0f};
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vec3s dp1 = glms_vec3_sub(top_right, top_left);
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vec3s dp2 = glms_vec3_sub(bottom_right, top_left);
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vec2s duv1 = glms_vec2_sub(uv1, uv0);
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vec2s duv2 = glms_vec2_sub(uv3, uv0);
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float r = 1.0f / (duv1.x * duv2.y - duv1.y * duv2.x);
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vec3s tangent = glms_vec3_scale(glms_vec3_sub(glms_vec3_scale(dp1, duv2.y), glms_vec3_scale(dp2, duv1.y)), r);
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vertex_t vertex_0 = {.position = top_left, .normal = forward, .tangent = tangent, .uv = {0.0f, 0.0f}};
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vertex_t vertex_1 = {.position = top_right, .normal = forward, .tangent = tangent, .uv = {1.0f, 0.0f}};
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vertex_t vertex_2 = {.position = bottom_right, .normal = forward, .tangent = tangent, .uv = {1.0f, 1.0f}};
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vertex_t vertex_3 = {.position = bottom_left, .normal = forward, .tangent = tangent, .uv = {0.0f, 1.0f}};
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triangle_create(vertex_0, vertex_1, vertex_3, material_id, collection);
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triangle_create(vertex_1, vertex_2, vertex_3, material_id, collection);
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}
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#endif // GEOMETRY_UTILITIES_H
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