#include <raylib.h>
#include <rdrawing.h>
#include <math.h>

#define RAYGUI_IMPLEMENTATION
#include <raygui/raygui.h>

void updateRadius(int baseL, int innerL, int *pBaseR, int *pInnerR) {
	int totalL=baseL;
	if (innerL>baseL)
		totalL = (2*innerL-baseL);
	int totalR = 420;
	int remainder = totalR % totalL;
	if (remainder!=0) {
		if (remainder < totalL / 2) {
			totalR -= remainder;
		} else {
			totalR += ( totalL - remainder);
		}
	}
	if (innerL<baseL) {
		*pBaseR = totalR;
		*pInnerR = (totalR) / totalL * innerL;		
	} else {
		*pBaseR = (totalR) / totalL * baseL;		
		*pInnerR = totalR / totalL * innerL;
	}
}


int main() {
	int baseL=2;
	int innerL=3;
	int baseR,innerR;
	int cx=450,cy=450;
	int speed = 1;
	Color trackColor = BLUE;
	updateRadius(baseL, innerL, &baseR, &innerR);
	InitWindow(1300,900,"Hypotrochoid");
	SetTraceLogLevel(LOG_WARNING);
	SetTargetFPS(60);
	GuiSetStyle(DEFAULT,TEXT_SIZE,20);
	
	Image trackImage=GenImageColor(900,900,WHITE);
	//border
	ImageFillRectangleEx(&trackImage,0,0,900,900,LIGHTGRAY);
	ImageFillRectangleEx(&trackImage,5,5,890,890,WHITE);
	
	Image circlesImage = GenImageColor(900,900,BLANK);
	float r=0;
	int lastx,lasty;
	lasty=cy;
	lastx=cx+baseR;
	int frameCount = 0;
	while(!WindowShouldClose()) {
		//GUI
		int newInnerL = GuiSliderBar((Rectangle){ 70, 20, 200, 30 },"Inner",TextFormat("%i", (int)innerL), innerL, 1, 50);
		int newBaseL = GuiSliderBar((Rectangle){ 70, 60, 200, 30 },"Base",TextFormat("%i", (int)baseL), baseL, 1, 50);
		speed = GuiSliderBar((Rectangle){ 70, 120, 200, 30 },"Speed",TextFormat("%i", (int)speed), speed, 1, 50);
		GuiLabel((Rectangle){ 20, 220, 80, 30 },TextFormat("Color: 0x%X%X%X ",(int)(trackColor.r), (int)(trackColor.g),(int)(trackColor.b)));
		trackColor= GuiColorPicker((Rectangle){ 50, 250, 196, 192 }, NULL, trackColor);
		int doClear = GuiButton((Rectangle){ 120, 700, 80, 30 },"Clear");
		if (newInnerL!=innerL || newBaseL!=baseL) {
			innerL=newInnerL;
			baseL=newBaseL;
			updateRadius(baseL, innerL, &baseR, &innerR);
			lasty=cy;
			lastx=cx+baseR;
			r=0;
			ImageClearBackground(&trackImage,WHITE);
			ImageFillRectangleEx(&trackImage,0,0,900,900,LIGHTGRAY);
			ImageFillRectangleEx(&trackImage,5,5,890,890,WHITE);			
		} else if (doClear) {
			ImageClearBackground(&trackImage,WHITE);
			ImageFillRectangleEx(&trackImage,0,0,900,900,LIGHTGRAY);
			ImageFillRectangleEx(&trackImage,5,5,890,890,WHITE);						
		}
		//update datas
		r+=0.01;
		float innerCX=cx+ (baseR-innerR)*cos(r);
		float innerCY=cy+ (baseR-innerR)*sin(r);
		float theta = r * baseL / innerL; 
		int x=round(innerCX + innerR * cos(theta));
		int y=round(innerCY + innerR * sin(theta));		
		
		//update image (in CPU)
		//ImageClearBackground(&trackImage,WHITE);
		ImageDrawLineEx(&trackImage,lastx,lasty,x,y,3,trackColor);
		
		frameCount++;
		if (frameCount>=speed) {
			ImageClearBackground(&circlesImage,BLANK);
			//base circle
			ImageDrawCircleEx(&circlesImage,cx,cy,baseR,1,LIGHTRED);
			ImageDrawCircleEx(&circlesImage,innerCX,innerCY,innerR,1,LIGHTSLATEGRAY);
			ImageDrawPointEx(&circlesImage,x,y,7,RED);
			
			//Drawing in GPU
			Texture trackTexture = LoadTextureFromImage(trackImage);
			Texture circlesTexture = LoadTextureFromImage(circlesImage);
			BeginDrawing();
			ClearBackground(WHITE);
			DrawTexture(trackTexture,300,0,WHITE);
			DrawTexture(circlesTexture,300,0,WHITE);
			EndDrawing();
			UnloadTexture(circlesTexture);
			UnloadTexture(trackTexture);
			frameCount=0;			
		}
		
		lastx=x;
		lasty=y;
	}
	
	//Clean up
	UnloadImage(circlesImage);
	UnloadImage(trackImage);
	CloseWindow();
}