Cirno2022/script/KevinSystem/kevin_system/Kevin_EffectLib.dnh

//let imgEffect = dirCurrent ~ "./img/Kevin_Effect.png";
int PetalEffect = ObjParticleList_Create(OBJ_PARTICLE_LIST_2D);

task InitEffect(){
	_EffectListPreRender(PetalEffect, imgEffect, [0, 0, 256, 256]);
}

let imgEffect = dirCurrent ~ "./img/Kevin_Effect.png";

// Enemy deletion/explosion effects.

// This particle list is used for all instances of the effect.

task _EffectListPreRender(
	int targetList,
	texture, int[] rect
	){
	
		ObjPrim_SetTexture(targetList, texture);
		
		Obj_SetRenderPriorityI(targetList, 39);
		ObjPrim_SetPrimitiveType(targetList, PRIMITIVE_TRIANGLELIST);
		ObjPrim_SetVertexCount(targetList, 4);
		
		ObjRender_SetBlendType(targetList, BLEND_ALPHA);
	
		// Left-top, right-top, left-bottom, right-bottom
		
		ObjPrim_SetVertexUVT(targetList, 0, rect[0], rect[1]);
		ObjPrim_SetVertexUVT(targetList, 1, rect[2], rect[1]);
		ObjPrim_SetVertexUVT(targetList, 2, rect[0], rect[3]);
		ObjPrim_SetVertexUVT(targetList, 3, rect[2], rect[3]);
		
		// Vertex positions are offset with deltas so that the sprite is centered
		
		float dU = (rect[2] - rect[0])/2;
		float dV = (rect[3] - rect[1])/2;
		
		ObjPrim_SetVertexPosition(targetList, 0, -dU, -dV, 1);
		ObjPrim_SetVertexPosition(targetList, 1, dU, -dV, 1);
		ObjPrim_SetVertexPosition(targetList, 2, -dU, dV, 1);
		ObjPrim_SetVertexPosition(targetList, 3, dU, dV, 1);
		
		ObjPrim_SetVertexIndex(targetList, [0, 1, 2, 1, 2, 3]);
	
	}
	
// Enemy go Boom

/*
5 flower petals appear from the enemy and spin outwards.
Their angle constantly changes and their alpha lowers over time.
*/

task _ExplosionEffect(float enmX, float enmY, int targetList){

	int i = 0;
	int effectLength = 45;
	int effectNum = 5;
	int dir = 1;

	Obj_SetRenderPriorityI(targetList, 40);
	//TExplosionA(enmX, enmY, 255/effectLength, 9/effectLength);
	
	/*ascent(i in 0..effectNum){
		_CreatePetal(prand(5, 10)*dir, prand(5, 10)*dir, prand(0, 360));
		dir *= -1;
		//_CreatePetal(prand(50, 80), prand(-80, -50), prand(0, 360));
	}*/
	
	_CreatePetal(prand(8, 11), prand(-8, -11), prand(0, 360));
	_CreatePetal(prand(-11, -8), prand(-2, 2), prand(0, 360));
	_CreatePetal(prand(8, 8), prand(-2, 2), prand(0, 360));
	_CreatePetal(prand(-11, -8), prand(8, 11), prand(0, 360));
	_CreatePetal(prand(8, 11), prand(8, 11), prand(0, 360));
	
	ObjSound_Play(sfxBoom);
	
	// Create a petal with:
	// x offset every frame, y offset every frame
	
	task _CreatePetal(float spdX, float spdY, float baseAng){
	
		float x = enmX, y = enmY;
		let x_speed = spdX;
		let y_speed = spdY;
		let z_add = prand(-5, 5);
		
		ascent(i in 0..effectLength){
			_PetalMovement(Interpolate_Decelerate(1.5, 0.5, i/effectLength), Interpolate_Decelerate(255, 0, i/effectLength));
			yield;
		}
	
		task _PetalMovement(scale, alpha){
			
			ObjParticleList_SetScale(targetList, scale);
			ObjParticleList_SetAngleZ(targetList, baseAng);
			ObjParticleList_SetPosition(targetList, x, y, 1);
			ObjParticleList_SetAlpha(targetList, alpha);
			
			//Submits the current data to an instance, cleared every frame.
			ObjParticleList_AddInstance(targetList);
		
			x += x_speed;
			y += y_speed;
			baseAng += z_add;
			
			yield;
		
		}
		
	}
	
}