79 lines
2.7 KiB
C
79 lines
2.7 KiB
C
#ifndef DGL_DGLMATH_H_INCLUDED
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#define DGL_DGLMATH_H_INCLUDED
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#include "dglcmn.h"
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#include "dglvec2.h"
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#include <math.h>
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#define TOLERANCE 0.00001f
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#define PI 3.1415927f
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#define PI_OVER_180 (PI / 180.0f)
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#define RADIANS_0 0.0f
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#define RADIANS_45 (PI / 4.0f)
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#define RADIANS_90 (PI / 2.0f)
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#define RADIANS_135 ((3.0f * PI) / 4.0f)
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#define RADIANS_180 PI
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#define RADIANS_225 ((5.0f * PI) / 4.0f)
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#define RADIANS_270 ((3.0f * PI) / 2.0f)
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#define RADIANS_315 ((7.0f * PI) / 4.0f)
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#define RADIANS_360 (PI * 2.0f)
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#define DEG_TO_RAD(degrees) ((degrees) * PI_OVER_180)
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#define RAD_TO_DEG(radians) ((radians) * (1.0f / PI_OVER_180))
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#define CLAMP(value, low, high) (((value) < (low) ? (low) : ((value) > (high) ? (high) : (value))))
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#define LERP(a, b, t) ((a) + ((b) - (a)) * (t))
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#define INVERSE_LERP(a, b, lerped) (((lerped) - (a)) / ((b) - (a)))
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#define SCALE_RANGE(value, from_min, from_max, to_min, to_max) \
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(((value) / (((from_max) - (from_min)) / ((to_max) - (to_min)))) + (to_min))
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float angle_between_i(int x1, int y1, int x2, int y2);
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float angle_between_f(float x1, float y1, float x2, float y2);
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int next_power_of_2(int n);
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void point_on_circle(float radius, float radians, float *x, float *y);
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static VECTOR2F direction_from_angle(float radians);
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static float round(float value);
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static float symmetrical_round(float value);
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static boolean close_enough(float a, float b, float tolerance);
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static boolean power_of_2(int n);
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static float smooth_step(float low, float high, float t);
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// --------------------------------------------------------------------------
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static VECTOR2F direction_from_angle(float radians) {
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VECTOR2F direction;
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point_on_circle(1.0f, radians, &direction.x, &direction.y);
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return direction;
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}
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static float round(float value) {
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return ceil(value + 0.5f);
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}
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static float symmetrical_round(float value) {
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if (value > 0.0f)
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return floor(value + 0.5f);
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else
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return ceil(value - 0.5f);
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}
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static boolean close_enough(float a, float b, float tolerance) {
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//return fabs((a - b) / ((b == 0.0f) ? 1.0f : b)) < tolerance;
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// TODO: this is not the best way
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return fabs(a - b) <= tolerance;
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}
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static boolean power_of_2(int n) {
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return (n != 0) && !(n & (n - 1));
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}
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static float smooth_step(float low, float high, float t) {
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float n = CLAMP(t, 0.0f, 1.0f);
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return LERP(low, high, (n * n) * (3.0f - (2.0f * n)));
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}
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#endif
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