import math

const decay = 100

fn test_mix() {
	assert math.mix(0.0, 100.0, 0.0) == 0.0
	assert math.mix(0.0, 100.0, 0.1) == 10.0
	assert math.mix(0.0, 100.0, 0.2) == 20.0
	assert math.mix(0.0, 100.0, 0.5) == 50.0
	assert math.mix(0.0, 100.0, 0.8) == 80.0
	assert math.mix(0.0, 100.0, 0.9) == 90.0
	assert math.mix(0.0, 100.0, 1.0) == 100.0

	assert math.mix(100.0, 500.0, 0.0) == 100.0
	assert math.mix(100.0, 500.0, 0.1) == 140.0
	assert math.mix(100.0, 500.0, 0.2) == 180.0
	assert math.mix(100.0, 500.0, 0.5) == 300.0
	assert math.mix(100.0, 500.0, 0.8) == 420.0
	assert math.mix(100.0, 500.0, 0.9) == 460.0
	assert math.mix(100.0, 500.0, 1.0) == 500.0
}

fn test_exp_decay() {
	assert math.exp_decay(0.0, 100.0, decay, 0.0) == 0.0
	assert math.exp_decay(0.0, 100.0, decay, 1.0) == 100.0

	assert math.exp_decay(100.0, 500.0, decay, 0.0) == 100.0
	assert math.exp_decay(100.0, 500.0, decay, 1.0) == 500.0

	assert math.exp_decay(0, 100, decay, 0.0) == 0
	assert math.exp_decay(0, 100, decay, 1.0) == 100

	assert math.exp_decay(100, 500, decay, 0.0) == 100
	assert math.exp_decay(100, 500, decay, 1.0) == 500
}

fn test_clip() {
	assert math.clip(0.0, 10.0, 50.0) == 10.0
	assert math.clip(5.5, 10.0, 50.0) == 10.0
	assert math.clip(10.0, 10.0, 50.0) == 10.0
	assert math.clip(20.0, 10.0, 50.0) == 20.0
	assert math.clip(50.0, 10.0, 50.0) == 50.0
	assert math.clip(80.0, 10.0, 50.0) == 50.0
	assert math.clip(90.5, 10.0, 50.0) == 50.0

	assert math.clip(0, 10, 50) == 10
	assert math.clip(5, 10, 50) == 10
	assert math.clip(10, 10, 50) == 10
	assert math.clip(20, 10, 50) == 20
	assert math.clip(50, 10, 50) == 50
	assert math.clip(80, 10, 50) == 50
	assert math.clip(90, 10, 50) == 50
}

// The test curve control points are taken from: https://cubic-bezier.com/#.19,-0.09,.42,1.19
const b = [
	math.BezierPoint{0, 0},
	math.BezierPoint{0.19, -0.09},
	math.BezierPoint{0.42, 1.19},
	math.BezierPoint{1.0, 1.0},
]
const bx = b.map(it.x)
const by = b.map(it.y)
const bx_fa = [4]f64{init: b[index].x}
const by_fa = [4]f64{init: b[index].y}

fn test_cubic_bezier() {
	assert math.cubic_bezier(0.0, b) == math.BezierPoint{b[0].x, b[0].x}
	assert math.cubic_bezier(0.5, b) == math.BezierPoint{0.35375, 0.5375}
	assert math.cubic_bezier(1.0, b) == math.BezierPoint{b[3].x, b[3].x}
}

fn test_cubic_bezier_a() {
	assert math.cubic_bezier_a(0.0, bx, by) == math.BezierPoint{bx[0], by[0]}
	assert math.cubic_bezier_a(0.5, bx, by) == math.BezierPoint{0.35375, 0.5375}
	assert math.cubic_bezier_a(1.0, bx, by) == math.BezierPoint{bx[3], by[3]}
}

fn test_cubic_bezier_fa() {
	assert math.cubic_bezier_fa(0.0, bx_fa, by_fa) == math.BezierPoint{bx_fa[0], by_fa[0]}
	assert math.cubic_bezier_fa(0.5, bx_fa, by_fa) == math.BezierPoint{0.35375, 0.5375}
	assert math.cubic_bezier_fa(1.0, bx_fa, by_fa) == math.BezierPoint{bx_fa[3], by_fa[3]}
}

fn test_remap() {
	assert math.remap(20, 1, 100, 50, 5000) == 1000
	assert math.remap(20.0, 1, 100, 50, 5000) == 1000.0

	assert math.remap(55, 1, 100, 52, 5000) == 2750
	assert math.remap(55.0, 1, 100, 52, 5000) == 2750.909090909091

	assert math.remap(25, 1, 100, 50, 5000) == 1250
	assert math.remap(25, 1, 100, -50, -5000) == -1250
	assert math.remap(25, 1, 100, 5000, 50) == 3800
	assert math.remap(25, 1, 100, -5000, -50) == -3800
	assert math.remap(25, 100, 1, 50, 5000) == 3800
	assert math.remap(25, 100, 1, -50, -5000) == -3800
	assert math.remap(25, 100, 1, 5000, 50) == 1250
	assert math.remap(25, 100, 1, -5000, -50) == -1250
}

fn test_smoothstep() {
	assert math.smoothstep(0.0, 1, 0) == 0
	assert math.close(math.smoothstep(0.0, 1, 0.05), 0.00725)
	assert math.close(math.smoothstep(0.0, 1, 0.1), 0.028)
	assert math.smoothstep(0.0, 1, 0.5) == 0.5
	assert math.close(math.smoothstep(0.0, 1, 0.9), 0.972)
	assert math.close(math.smoothstep(0.0, 1, 0.95), 0.99275)
	assert math.smoothstep(0.0, 1, 1) == 1
}

fn test_smootherstep() {
	assert math.smootherstep(0.0, 1, 0) == 0
	assert math.close(math.smootherstep(0.0, 1, 0.05), 0.001158125)
	assert math.close(math.smootherstep(0.0, 1, 0.1), 0.00856)
	assert math.smootherstep(0.0, 1, 0.5) == 0.5
	assert math.close(math.smootherstep(0.0, 1, 0.9), 0.99144)
	assert math.close(math.smootherstep(0.0, 1, 0.95), 0.998841875)
	assert math.smootherstep(0.0, 1, 1) == 1
}