rockets_math.h

#ifndef _rockets_math_h
#define _rockets_math_h

#include <math.h>

// Math
#define CLAMP(x,xmin,xmax)  ((x) < (xmin) ? (xmin) : (x) > (xmax) ? (xmax) : (x))

float
deg_to_rad(float deg)
{
    return deg * M_PI / 180.0;
}

/* bool */
/* bounds_contains(float top_leftx, float top_lefty, */
/*                 float bottom_rightx, float bottom_righty, */
/*                 float x, float y) */
/* { */
/*     return (x >= top_leftx && x <= bottom_rightx && */
/*             y >= top_lefty && y <= bottom_righty); */
/* } */

// Vectors
typedef union {
    struct {float x; float y;};
    float arr[2];
} V2;

V2
v2(float x, float y)
{
    return (V2){.x = x, .y = y};
}


V2
v2_plus(V2 i, V2 j)
{
    return v2(i.x + j.x,
              i.y + j.y);
}


V2
v2_minus(V2 i, V2 j)
{
    return v2(i.x - j.x,
              i.y - j.y);
}


V2
v2_scale(V2 v, float f)
{
    return v2(v.x * f,
              v.y * f);
}


V2
v2_rotate(V2 v, float radians)
{
    float nx = v.x * cos(radians) - v.y * sin(radians);
    float ny = v.x * sin(radians) + v.y * cos(radians);

    return v2(nx, ny);
}

/* // Bounding Box */
/* typedef struct BoundingBox { */
/*     V2 top_left; */
/*     V2 bottom_right; */
/* } BoundingBox; */

/* /\* Bounding Box *\/ */

/* BoundingBox */
/* boundingBox(V2 top_left, float width, float height) */
/* { */
/*     return (BoundingBox){top_left, v2_plus(top_left, v2(width, height))}; */
/* } */


/* bool */
/* bb_contains(BoundingBox bb, float x, float y) */
/* { */
/*     return bounds_contains(bb.top_left.x, */
/*                            bb.top_left.y, */
/*                            bb.bottom_right.x, */
/*                            bb.bottom_right.y, x, y); */
/* } */


/* V2 */
/* bb_center(BoundingBox bb) */
/* { */
/*     float centerx = ((bb.bottom_right.x - bb.top_left.x) / 2) */
/*         + bb.top_left.x; */
/*     float centery = ((bb.bottom_right.y - bb.top_left.y) / 2) */
/*         + bb.top_left.y; */

/*     return v2(centerx, centery); */
/* } */


/* // Calculate width and height of bb */
/* V2 */
/* bb_size(BoundingBox bb) */
/* { */
/*     return v2(bb.bottom_right.x - bb.top_left.x, */
/*               bb.bottom_right.y - bb.top_left.y); */
/* } */


/* // up the size of a bb by 1 */
/* BoundingBox */
/* bb_blow_up(BoundingBox bb) */
/* { */
/*     bb.top_left.x -= 1; */
/*     bb.top_left.y -= 1; */
/*     bb.bottom_right.x += 2; */
/*     bb.bottom_right.y += 2; */
/*     return bb; */
/* } */

#endif