#include <acknex.h>
#include <default.c>

VIEW *pp_view = { layer = 2; flags = PROCESS_TARGET | CHILD; }

MATERIAL *mtl_2d_lights =
{
	effect = "
	//https://www.shadertoy.com/view/ttj3zd

	float4x4 matProj;
	const float4 vecTime;
	const float4 vecViewPort;

	float smoothObjectPadding = 0.33;
	float flickerSpeedFactor = 2;

	float iLights;
	float4 vecLightPos[8];
	float4 vecLightViewPos[8];
	float4 vecLightDir[8];
	float4 vecLightColor[8];

	texture TargetMap;

	sampler postTex = sampler_state
	{
		texture = <TargetMap>;
		MinFilter = Point;
	};

	float4 FP(
	in float2 inTex : TEXCOORD0, 
	in float2 inPos : VPOS) : COLOR
	{
		float3 color = tex2D(postTex, inTex).rgb;
		float3 blurColor = float3(0.0, 0.0, 0.0);
		
		float i = 0;
		for(i = 0; i < iLights; i += 1.0)
		{
			// pointlights only
			// checking only .w doesn't help to skip the sun
			if(vecLightDir[i].x <= 0 && vecLightDir[i].y <= 0 && vecLightDir[i].z <= 0)
			{
				float4 clipSpacePos = mul(float4(vecLightViewPos[i].xyz, 1.0f), matProj);
				float2 ndcSpacePos = clipSpacePos.xy / clipSpacePos.w;
				float2 windowSpacePos = float2(1.0f + ndcSpacePos.x, 1.0f - ndcSpacePos.y) * vecViewPort.xy * 0.5f;
				float4 clipSpaceOutterPoint = mul(float4(vecLightViewPos[i].x - vecLightPos[i].w, vecLightViewPos[i].yz, 1.0f), matProj);
				float ndcSpaceOutterPoint = clipSpaceOutterPoint.x / clipSpaceOutterPoint.w;
				float windowSpaceRadius = (ndcSpacePos.x - ndcSpaceOutterPoint) * vecViewPort.x * 0.5f;
				
				float2 objectCenter = windowSpacePos.xy / vecViewPort.xy;
				float2 uv = length(inPos - windowSpacePos);
				float2 pos = uv - objectCenter;
				
				float flickerTime = sin(vecTime.w * flickerSpeedFactor);
				float min_size = windowSpaceRadius;
				float max_size = windowSpaceRadius + 8;
				float size = lerp(min_size, max_size, flickerTime);
				
				float smoothSize = size * smoothObjectPadding;
				float circleMix = smoothstep(size, size - smoothSize, length(pos));
				
				blurColor.rgb = lerp(blurColor.rgb, color.rgb * vecLightColor[i].rgb, circleMix);
			}
		}
		
		float4 fragColor = float4(blurColor, 1.0);
		return fragColor;
	}

	technique
	{
		pass one
		{
			ZWriteEnable = False;
			AlphaBlendEnable = False;
			PixelShader = compile ps_3_0 FP();
		}
	}	
	";
}

action act_light()
{
	set(my, PASSABLE);
	vec_set(&my->blue, vector(128 + random(128), 128 + random(128), 128 + random(128)));
	my->lightrange = 128;
}

void main()
{
	video_mode = 10;
	warn_level = 6;
	sun_light = 0;
	level_load("");
	
	random_seed(0);
	camera->arc = 90;
	
	vec_set(&camera->x, vector(0, 300, 300));
	vec_set(&camera->pan, vector(270, -45, 0));
	
	pp_view->material = mtl_2d_lights;	
	camera->stage = pp_view;	
	
	ENTITY *ent = ent_create(CUBE_MDL, nullvector, NULL);
	vec_set(&ent->scale_x, vector(64, 64, 0.01));
	c_setminmax(ent);
	
	int i = 0;
	for(i = 0; i < 3; i++)
	{
		ent_create(CUBE_MDL, vector(-128 + (128 * i), 0, 16), act_light);
	}
}