global uniform float beat;
global uniform float bar;
global uniform float song_time;
global uniform float total_song_time;
global uniform float user_offset_ms;

uniform float phase_offset = 0.0;
uniform float phase_multiplier = 1.0;

instance uniform float instance_phase_offset = 0.0;
instance uniform float instance_phase_multiplier = 1.0;


float get_beat_with_offset() {
	return (beat * phase_multiplier * instance_phase_multiplier) + phase_offset + instance_phase_offset;// + (user_offset_ms / 1000.0);
}


float get_bar_with_offset() {
	return (bar * phase_multiplier * instance_phase_multiplier) + phase_offset + instance_phase_offset;// + (user_offset_ms / 1000.0);
}


float get_beat_phase() {
	float beat_offset = get_beat_with_offset();
	return beat_offset - floor(beat_offset);
}


float get_bar_phase() {
	float bar_offset = get_bar_with_offset();
	return bar_offset - floor(bar_offset);
}

float get_song_time_ratio() {
	return song_time / max(total_song_time, 0.001);
}

float ease(float x, float c) {
	// Godot's source code converted via ChatGPT to GLSL-style
	//branchless:
	//x = clamp(x, 0.0, 1.0);
	//float pos = mix(
		//1.0 - pow(1.0 - x, 1.0 / c),
		//pow(x, c),
		//step(1.0, c)
	//);
	//
	//float k = -c;
	//float x2 = x * 2.0;
	//float inout_v = mix(
		//pow(x2, k) * 0.5,
		//(1.0 - pow(2.0 - x2, k)) * 0.5 + 0.5,
		//step(0.5, x)
	//);
	//
	//float isPos = step(0.0, c);
	//float isNeg = step(c, 0.0);
	//
	//return pos * isPos + inout_v * isNeg;
	
	// a few branches:
	x = clamp(x, 0.0, 1.0);
	
	float pos = mix(
		1.0 - pow(1.0 - x, 1.0 / c), // 0 < c < 1
		pow(x, c), // c >= 1
		step(1.0, c)
	);
	
	float k = -c;
	float x2 = x * 2.0;
	float inout_v = mix(
		pow(x2, k) * 0.5,
		(1.0 - pow(2.0 - x2, k)) * 0.5 + 0.5,
		step(0.5, x)
	);
	
	return (c > 0.0) ? pos :
			(c < 0.0) ? inout_v :
			0.0;
			
	// From godot's source code:
	//if (x < 0.0) {
		//x = 0.0;
	//} else if (x > 1.0) {
		//x = 1.0;
	//}
	//if (c > 0.0) {
		//if (c < 1.0) {
			//return 1.0 - pow(1.0 - x, 1.0 / c);
		//} else {
			//return pow(x, c);
		//}
	//} else if (c < 0.0) {
		////inout ease
//
		//if (x < 0.5) {
			//return pow(x * 2.0, -c) * 0.5;
		//} else {
			//return (1.0 - pow(1.0 - (x - 0.5) * 2.0, -c)) * 0.5 + 0.5;
		//}
	//} else {
		//return 0.0; // no ease (raw)
	//}
}