diff options
Diffstat (limited to 'math_helper.c')
| -rw-r--r-- | math_helper.c | 124 |
1 files changed, 0 insertions, 124 deletions
diff --git a/math_helper.c b/math_helper.c deleted file mode 100644 index 648fbd2..0000000 --- a/math_helper.c +++ /dev/null @@ -1,124 +0,0 @@ -#include "include/math_helper.h" - - -bool onSegment(vec2f p, vec2f q, vec2f r) -{ - if (q.x <= max(p.x, r.x) && q.x >= min(p.x, r.x) && - q.y <= max(p.y, r.y) && q.y >= min(p.y, r.y)) - return true; - - return false; -} - -int orientation(vec2f p, vec2f q, vec2f r) -{ - int val = (q.y - p.y) * (r.x - q.x) - - (q.x - p.x) * (r.y - q.y); - - if (val == 0) return 0; // collinear - - return (val > 0)? 1: 2; // clock or counterclock wise -} - -vec2f get_dir_of_line(vec2f p1, vec2f p2) { - float dirx = (p1.x - p2.x); - float diry = (p1.y - p2.y); - double length = sqrt(dirx * dirx + diry * diry); - dirx /= length; - diry /= length; - return (vec2f){dirx, diry}; -} - -bool neg2(float p1, float p2) { - return p1 < 0.0f && p2 < 0.0f || abs(p1-p2) < 1.0f; -} - -bool pos2(float p1, float p2) { - return (p1 >= 0.0f && p2 >= 0.0f) || abs(p1-p2) < 1.0f; -} - - -bool lines_intersect(vec2f p1, vec2f q1, vec2f p2, vec2f q2) -{ - int o1 = orientation(p1, q1, p2); - int o2 = orientation(p1, q1, q2); - int o3 = orientation(p2, q2, p1); - int o4 = orientation(p2, q2, q1); - - // General case - if (o1 != o2 && o3 != o4) { - vec2f bdir = get_dir_of_line(p1, q1); - vec2f pdir = get_dir_of_line(p1, p2); - if (((p1.x <= p2.x && q1.x >= p2.x) || (p1.x >= p2.x && q1.x <= p2.x)) || ((p1.y <= p2.y && q1.y >= p2.y) || (p1.y >= p2.y && q1.y <= p2.y))) - if ((neg2(bdir.x, pdir.x) || pos2(bdir.x, pdir.x)) && (neg2(bdir.y, pdir.y) || pos2(bdir.y, pdir.y))) return true; - } - - // Special Cases - // p1, q1 and p2 are collinear and p2 lies on segment p1q1 - if (o1 == 0 && onSegment(p1, p2, q1)) return true; - - // p1, q1 and q2 are collinear and q2 lies on segment p1q1 - if (o2 == 0 && onSegment(p1, q2, q1)) return true; - - // p2, q2 and p1 are collinear and p1 lies on segment p2q2 - if (o3 == 0 && onSegment(p2, p1, q2)) return true; - - // p2, q2 and q1 are collinear and q1 lies on segment p2q2 - if (o4 == 0 && onSegment(p2, q1, q2)) return true; - - return false; // Doesn't fall in any of the above cases -} - -vec2f get_intersection_point(vec2f A, vec2f B, vec2f C, vec2f D) { - // Line AB represented as a1x + b1y = c1 - double a1 = B.y - A.y; - double b1 = A.x - B.x; - double c1 = a1*(A.x) + b1*(A.y); - - // Line CD represented as a2x + b2y = c2 - double a2 = D.y - C.y; - double b2 = C.x - D.x; - double c2 = a2*(C.x)+ b2*(C.y); - - double determinant = a1*b2 - a2*b1; - - if (determinant == 0) - { - // The lines are parallel. This is simplified - // by returning a pair of FLT_MAX - return (vec2f){__FLT_MAX__, __FLT_MAX__}; - } - else - { - double x = (b2*c1 - b1*c2)/determinant; - double y = (a1*c2 - a2*c1)/determinant; - return (vec2f){x, y}; - } -} - -box get_box_of_square(platform_window* window, vec3f position, vec3f size) { - map_info info = get_map_info(window); - vec2f rendertl = (vec2f){position.x, position.y}; - vec2f rendertr = (vec2f){position.x + size.x, position.y}; - vec2f renderbr = (vec2f){position.x + size.x, position.y + size.y}; - vec2f renderbl = (vec2f){position.x, position.y + size.y}; - - return (box){rendertl, rendertr, renderbl, renderbr, rendertl, rendertr, renderbl, renderbr}; -} - -box get_render_box_of_square(platform_window* window, vec3f position, vec3f size) { - map_info info = get_map_info(window); - float render_x = (info.tile_width * position.x) + (info.px_incline * position.y); - vec2f rendertl = (vec2f){render_x, info.tile_width * position.y - position.z*info.px_raised_per_h}; - vec2f rendertr = (vec2f){render_x + info.tile_width*size.x, info.tile_height * position.y - position.z*info.px_raised_per_h}; - vec2f renderbr = (vec2f){render_x + (info.px_incline+info.tile_width)*size.x, info.tile_height * position.y + info.tile_height*size.y - position.z*info.px_raised_per_h}; - vec2f renderbl = (vec2f){render_x + info.px_incline*size.x, info.tile_height * position.y + info.tile_height*size.y - position.z*info.px_raised_per_h}; - - position.z += size.z; - vec2f rendertl2 = (vec2f){render_x, info.tile_width * position.y - position.z*info.px_raised_per_h}; - vec2f rendertr2 = (vec2f){render_x + info.tile_width*size.x, info.tile_height * position.y - position.z*info.px_raised_per_h}; - vec2f renderbr2 = (vec2f){render_x + (info.px_incline+info.tile_width)*size.x, info.tile_height * position.y + info.tile_height*size.y - position.z*info.px_raised_per_h}; - vec2f renderbl2 = (vec2f){render_x + info.px_incline*size.x, info.tile_height * position.y + info.tile_height*size.y - position.z*info.px_raised_per_h}; - - return (box){rendertl, rendertr, renderbl, renderbr, rendertl2, rendertr2, renderbl2, renderbr2}; -}
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