in vec3 position;
in vec2 texcoord;
in vec3 normal;

uniform highp mat4 modelMatrix;
uniform highp mat4 viewMatrix;
uniform highp mat4 projMatrix;
uniform highp mat4 normalMatrix;

uniform vec4 ambientLight;
uniform vec4 diffuse;
uniform vec4 ambient;

uniform int effectId;
uniform UBOOL effectSecondPass;
uniform float borderWidth;

uniform float fogStart;
uniform float fogEnd;
varying float fogFactor;

struct Light {
	vec4 _position;
	vec4 _direction;
	vec4 _color;
	float enabled;
};

const int maxLights = 8;
uniform Light lights[maxLights];

out vec2 Texcoord;
out vec4 Color;
out vec3 Normal;

void main() {
	if (effectId == 0) {
		Texcoord = texcoord;
		Color = diffuse;

		vec4 viewCoords = viewMatrix * modelMatrix * vec4(position, 1.0);
		gl_Position = projMatrix * viewCoords;

		vec3 light = vec3(0.0, 0.0, 0.0);
		vec3 normalEye = normalize((normalMatrix * vec4(normal, 0.0)).xyz);

		float fogCoord = abs(viewCoords.z);
		fogFactor = clamp((fogEnd - fogCoord) / (fogEnd - fogStart), 0.0, 1.0);

		for (int i = 0; i < maxLights; ++i) {
			if (lights[i].enabled < 0.0) {
				continue;
			}

			float intensity = 1.0;
			vec4 lightPosition = viewMatrix * lights[i]._position;
			vec3 vertexToLight = lightPosition.xyz - viewCoords.xyz;

			if (lights[i]._direction.w < 0.0) { // Spotlight
				vec4 lightDirection = viewMatrix * vec4(lights[i]._direction.xyz, 0.0);
				// See DirectX spotlight documentation
				float cosAngle = -dot(normalize(vertexToLight), normalize(lightDirection.xyz)); // rho
				float cosPenumbra = 0.968912; // cos(1 / 4)
				float cosUmbra = 0.877582; // cos(1 / 2)

				if (cosAngle <= cosPenumbra) {
					if (cosAngle < cosUmbra || cosPenumbra == cosUmbra) {
						intensity = 0.0;
					} else {
						intensity *= (cosAngle - cosUmbra) / (cosPenumbra - cosUmbra);
					}
				}
			}

			intensity *= max(0.0, dot(normalEye, normalize(vertexToLight)));
			light += lights[i]._color.rgb * intensity;
		}

		Color.rgb *= light;
		Color.rgb += ambient.rgb * ambientLight.rgb;

		Color.rgb = clamp(Color.rgb, 0.0, 1.0);
	} else if (effectId == 1) {
		Texcoord = texcoord;
		Color = vec4(0.0, 0.0, 0.0, 1.0);

		vec4 viewCoords = viewMatrix * modelMatrix * vec4(position, 1.0);
		vec4 pos = projMatrix * viewCoords;

		if (!UBOOL_TEST(effectSecondPass)) {
			vec3 nrm = (viewMatrix * modelMatrix * vec4(normal, 0.0)).xyz;
			pos.xy += nrm.xy * pos.w * borderWidth * 0.001;
		}

		gl_Position = pos;
	}
}
