101 lines
2.4 KiB
C
101 lines
2.4 KiB
C
#include <stdlib.h>
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#include <math.h>
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#include <stdio.h>
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#include "vector_stack.h"
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void vec_init(Vector* result, double x, double y, double z) {
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result->x = x;
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result->y = y;
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result->z = z;
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}
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void vec_null(Vector* result) {
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vec_init(result, 0.0, 0.0, 0.0);
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}
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void vec_mul_scalar(Vector* result, Vector v, double scalar) {
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vec_init(result, v.x * scalar,
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v.y * scalar,
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v.z * scalar);
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}
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double vec_mul_dot(Vector first, Vector second) {
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return first.x * second.x +
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first.y * second.y +
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first.z * second.z;
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}
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void vec_mul_cross(Vector* result, Vector first, Vector second) {
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return vec_init(result, first.y * second.z - first.z * second.y,
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first.z * second.x - first.x * second.z,
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first.x * second.y - first.y * second.x);
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}
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void vec_add(Vector* result, Vector first, Vector second) {
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return vec_init(result, first.x + second.x,
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first.y + second.y,
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first.z + second.z);
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}
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void vec_sub(Vector* result, Vector first, Vector second) {
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return vec_init(result, first.x - second.x,
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first.y - second.y,
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first.z - second.z);
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}
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int vec_equals(Vector first, Vector second) {
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return (first.x == second.x)
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&& (first.y == second.y)
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&& (first.z == second.z);
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}
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static const int MAX_LENGTH=128;
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char* vec_to_str(Vector v) {
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char* result = (char*) malloc(MAX_LENGTH);
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if (!result) {
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return NULL;
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}
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snprintf(result, MAX_LENGTH, "[ %.2f %.2f %.2f ]", v.x, v.y, v.z);
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return result;
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}
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void vec_print(Vector v) {
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char* str = vec_to_str(v);
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printf("%s", str);
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free(str);
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}
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double vec_length(Vector v) {
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return sqrt(v.x * v.x
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+ v.y * v.y
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+ v.z * v.z);
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}
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int vec_norm(Vector* result, Vector v) {
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double length = vec_length(v);
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if (length == 0.0) {
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/* no norm for a null vector */
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return -1;
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}
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vec_init(result, v.x / length,
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v.y / length,
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v.z / length);
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return 0;
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}
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int vec_collinear(Vector first, Vector second) {
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Vector cross, nullVector;
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vec_mul_cross(&cross, first, second);
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vec_null(&nullVector);
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int result = vec_equals(nullVector, cross);
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return result;
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}
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