using System;

using OpenTK.Graphics.OpenGL;

using org.budnhead.graphics;
using org.budnhead.tools;

namespace org.budnhead.core
{
	public static class GlobalDefaults
	{
		internal static bool initialize(){
			ResourceLibrary.initializeResourceType(typeof(Shader),			"shader/",	"");
			ResourceLibrary.initializeResourceType(typeof(ShaderProgram),	"shader/",	".program");
			ResourceLibrary.initializeResourceType(typeof(LoadedModel),		"models/",	".obj");

			ResourceLibrary.cacheInstance("default.vshader",new Shader(OpenTK.Graphics.OpenGL.ShaderType.VertexShader, defVertexShaderSource));
			ResourceLibrary.cacheInstance("default.fshader",new Shader(OpenTK.Graphics.OpenGL.ShaderType.FragmentShader, defFragmentShaderSource));

			ResourceLibrary.cacheInstance("default",new ShaderProgram("default.vshader","default.fshader"));

			return true;
		}



private static string defVertexShaderSource = @"#version 330
  
layout(location = 0) in vec3 iv_position;
layout(location = 1) in vec4 iv_color;
layout(location = 2) in vec3 iv_normal;
layout(location = 3) in vec4 iv_col2;
layout(location = 4) in vec2 iv_uv;

uniform mat4 mObject;
uniform mat4 mCamera;
uniform mat4 mObjectCamera;
uniform mat4 mObjectCameraIT;
uniform mat4 mProjection;
uniform mat4 mScene;

out vec4 color;
out vec3 norm;
out vec2 uv;
out vec3 coord;

out float	shading;

void main()
{
			gl_Position = mScene * vec4( iv_position, 1 );

	float	fading	= 1.0;
	
			norm	= normalize( ( mObjectCameraIT * vec4( iv_normal    , 1 ) ).xyz );
	vec3 	camray	= (mObjectCamera   * vec4( iv_position  , 1 )).xyz;
	vec3 	ncamray	= normalize( camray );
	float	distance = length(camray);
	float	idistance = clamp( 10000 / (distance), 0, 1);


/*
	float	cosTheta = abs( clamp(dot( norm , ncamray ), -1, 1) );

			shading = clamp(0.3 + (cosTheta * 0.7), 0, 1) * sight;
			color = clamp( vec4( iv_color.xyz, fading ) * iv_col2, 0, 1);
*/
			shading = 1.0;
			color = iv_color;
			coord	= ncamray;
}

";
		
private static string defFragmentShaderSource = @"#version 330

in vec4 color;
in vec3 norm;
in vec2 uv;
in vec3 coord;

in float shading;

out vec4 _color;

void main()
{
	float cosTheta = dot( coord, norm );
	
	if (cosTheta < 0){
		discard;
	};

	float shade = 0.2 + (0.8 * cosTheta);

    _color = clamp( vec4( color.xyz * shade, color.w ), 0, 1);
	//_color = vec4( (vec3( 1,1,1 ) + norm)/2 , 1 );
}

";

	}
}