#include "lc_global.h"
#include "lc_math.h"
#include "lc_colors.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <math.h>
#include "light.h"
#include "camera.h"
#include "view.h"
#include "lc_application.h"
#include "lc_context.h"

// New omni light.
lcLight::lcLight(float px, float py, float pz)
	: lcObject(LC_OBJECT_LIGHT)
{
	Initialize(lcVector3(px, py, pz), lcVector3(0.0f, 0.0f, 0.0f));
	UpdatePosition(1);
}

// New directional or spot light.
lcLight::lcLight(float px, float py, float pz, float tx, float ty, float tz)
	: lcObject(LC_OBJECT_LIGHT)
{
	Initialize(lcVector3(px, py, pz), lcVector3(tx, ty, tz));
	UpdatePosition(1);
}

void lcLight::Initialize(const lcVector3& Position, const lcVector3& TargetPosition)
{
	mState = 0;
	memset(m_strName, 0, sizeof(m_strName));

	ChangeKey(mPositionKeys, Position, 1, true);
	ChangeKey(mTargetPositionKeys, TargetPosition, 1, true);
	ChangeKey(mAmbientColorKeys, lcVector4(0.0f, 0.0f, 0.0f, 1.0f), 1, true);
	ChangeKey(mDiffuseColorKeys, lcVector4(0.8f, 0.8f, 0.8f, 1.0f), 1, true);
	ChangeKey(mSpecularColorKeys, lcVector4(1.0f, 1.0f, 1.0f, 1.0f), 1, true);
	ChangeKey(mAttenuationKeys, lcVector3(1.0f, 0.0f, 0.0f), 1, true);
	ChangeKey(mSpotCutoffKeys, 30.0f, 1, true);
	ChangeKey(mSpotExponentKeys, 0.0f, 1, true);
}

lcLight::~lcLight()
{
}

void lcLight::SaveLDraw(QTextStream& Stream) const
{
}

void lcLight::CreateName(const lcArray<lcLight*>& Lights)
{
	int i, max = 0;

	for (int LightIdx = 0; LightIdx < Lights.GetSize(); LightIdx++)
	{
		lcLight* pLight = Lights[LightIdx];

		if (strncmp(pLight->m_strName, "Light ", 6) == 0)
		{
			if (sscanf(pLight->m_strName + 6, " #%d", &i) == 1)
			{
				if (i > max)
					max = i;
			}
		}
	}

	sprintf(m_strName, "Light #%.2d", max+1);
}

void lcLight::CompareBoundingBox(float box[6])
{
	const lcVector3 Points[2] =
	{
		mPosition, mTargetPosition
	};

	for (int i = 0; i < (IsPointLight() ? 1 : 2); i++)
	{
		const lcVector3& Point = Points[i];

		if (Point[0] < box[0]) box[0] = Point[0];
		if (Point[1] < box[1]) box[1] = Point[1];
		if (Point[2] < box[2]) box[2] = Point[2];
		if (Point[0] > box[3]) box[3] = Point[0];
		if (Point[1] > box[4]) box[4] = Point[1];
		if (Point[2] > box[5]) box[5] = Point[2];
	}
}

void lcLight::RayTest(lcObjectRayTest& ObjectRayTest) const
{
	if (IsPointLight())
	{
		float Distance;

		if (lcSphereRayMinIntersectDistance(mPosition, 0.2f, ObjectRayTest.Start, ObjectRayTest.End, &Distance))
		{
			ObjectRayTest.ObjectSection.Object = const_cast<lcLight*>(this);
			ObjectRayTest.ObjectSection.Section = LC_LIGHT_SECTION_POSITION;
			ObjectRayTest.Distance = Distance;
		}

		return;
	}

	lcVector3 Min = lcVector3(-0.2f, -0.2f, -0.2f);
	lcVector3 Max = lcVector3(0.2f, 0.2f, 0.2f);

	lcVector3 Start = lcMul31(ObjectRayTest.Start, mWorldLight);
	lcVector3 End = lcMul31(ObjectRayTest.End, mWorldLight);

	float Distance;
	if (lcBoundingBoxRayMinIntersectDistance(Min, Max, Start, End, &Distance, NULL) && (Distance < ObjectRayTest.Distance))
	{
		ObjectRayTest.ObjectSection.Object = const_cast<lcLight*>(this);
		ObjectRayTest.ObjectSection.Section = LC_LIGHT_SECTION_POSITION;
		ObjectRayTest.Distance = Distance;
	}

	Min = lcVector3(-0.2f, -0.2f, -0.2f);
	Max = lcVector3(0.2f, 0.2f, 0.2f);

	lcMatrix44 WorldTarget = mWorldLight;
	WorldTarget.SetTranslation(lcMul30(-mTargetPosition, WorldTarget));

	Start = lcMul31(ObjectRayTest.Start, WorldTarget);
	End = lcMul31(ObjectRayTest.End, WorldTarget);

	if (lcBoundingBoxRayMinIntersectDistance(Min, Max, Start, End, &Distance, NULL) && (Distance < ObjectRayTest.Distance))
	{
		ObjectRayTest.ObjectSection.Object = const_cast<lcLight*>(this);
		ObjectRayTest.ObjectSection.Section = LC_LIGHT_SECTION_TARGET;
		ObjectRayTest.Distance = Distance;
	}
}

void lcLight::BoxTest(lcObjectBoxTest& ObjectBoxTest) const
{
	if (IsPointLight())
	{
		for (int PlaneIdx = 0; PlaneIdx < 6; PlaneIdx++)
			if (lcDot3(mPosition, ObjectBoxTest.Planes[PlaneIdx]) + ObjectBoxTest.Planes[PlaneIdx][3] > 0.2f)
				return;

		lcObjectSection& ObjectSection = ObjectBoxTest.ObjectSections.Add();
		ObjectSection.Object = const_cast<lcLight*>(this);
		ObjectSection.Section = LC_LIGHT_SECTION_POSITION;

		return;
	}

	lcVector3 Min(-0.2f, -0.2f, -0.2f);
	lcVector3 Max(0.2f, 0.2f, 0.2f);

	lcVector4 LocalPlanes[6];

	for (int PlaneIdx = 0; PlaneIdx < 6; PlaneIdx++)
	{
		lcVector3 Normal = lcMul30(ObjectBoxTest.Planes[PlaneIdx], mWorldLight);
		LocalPlanes[PlaneIdx] = lcVector4(Normal, ObjectBoxTest.Planes[PlaneIdx][3] - lcDot3(mWorldLight[3], Normal));
	}

	if (lcBoundingBoxIntersectsVolume(Min, Max, LocalPlanes))
	{
		lcObjectSection& ObjectSection = ObjectBoxTest.ObjectSections.Add();
		ObjectSection.Object = const_cast<lcLight*>(this);
		ObjectSection.Section = LC_LIGHT_SECTION_POSITION;
	}

	Min = lcVector3(-0.2f, -0.2f, -0.2f);
	Max = lcVector3(0.2f, 0.2f, 0.2f);

	lcMatrix44 WorldTarget = mWorldLight;
	WorldTarget.SetTranslation(lcMul30(-mTargetPosition, WorldTarget));

	for (int PlaneIdx = 0; PlaneIdx < 6; PlaneIdx++)
	{
		lcVector3 Normal = lcMul30(ObjectBoxTest.Planes[PlaneIdx], WorldTarget);
		LocalPlanes[PlaneIdx] = lcVector4(Normal, ObjectBoxTest.Planes[PlaneIdx][3] - lcDot3(WorldTarget[3], Normal));
	}

	if (lcBoundingBoxIntersectsVolume(Min, Max, LocalPlanes))
	{
		lcObjectSection& ObjectSection = ObjectBoxTest.ObjectSections.Add();
		ObjectSection.Object = const_cast<lcLight*>(this);
		ObjectSection.Section = LC_LIGHT_SECTION_TARGET;
	}
}

void lcLight::Move(lcStep Step, bool AddKey, const lcVector3& Distance)
{
	if (IsSelected(LC_LIGHT_SECTION_POSITION))
	{
		mPosition += Distance;
		ChangeKey(mPositionKeys, mPosition, Step, AddKey);
	}

	if (IsSelected(LC_LIGHT_SECTION_TARGET))
	{
		mTargetPosition += Distance;
		ChangeKey(mTargetPositionKeys, mTargetPosition, Step, AddKey);
	}
}

void lcLight::InsertTime(lcStep Start, lcStep Time)
{
	lcObject::InsertTime(mPositionKeys, Start, Time);
	lcObject::InsertTime(mTargetPositionKeys, Start, Time);
	lcObject::InsertTime(mAmbientColorKeys, Start, Time);
	lcObject::InsertTime(mDiffuseColorKeys, Start, Time);
	lcObject::InsertTime(mSpecularColorKeys, Start, Time);
	lcObject::InsertTime(mAttenuationKeys, Start, Time);
	lcObject::InsertTime(mSpotCutoffKeys, Start, Time);
	lcObject::InsertTime(mSpotExponentKeys, Start, Time);
}

void lcLight::RemoveTime(lcStep Start, lcStep Time)
{
	lcObject::RemoveTime(mPositionKeys, Start, Time);
	lcObject::RemoveTime(mTargetPositionKeys, Start, Time);
	lcObject::RemoveTime(mAmbientColorKeys, Start, Time);
	lcObject::RemoveTime(mDiffuseColorKeys, Start, Time);
	lcObject::RemoveTime(mSpecularColorKeys, Start, Time);
	lcObject::RemoveTime(mAttenuationKeys, Start, Time);
	lcObject::RemoveTime(mSpotCutoffKeys, Start, Time);
	lcObject::RemoveTime(mSpotExponentKeys, Start, Time);
}

void lcLight::UpdatePosition(lcStep Step)
{
	mPosition = CalculateKey(mPositionKeys, Step);
	mTargetPosition = CalculateKey(mTargetPositionKeys, Step);
	mAmbientColor = CalculateKey(mAmbientColorKeys, Step);
	mDiffuseColor = CalculateKey(mDiffuseColorKeys, Step);
	mSpecularColor = CalculateKey(mSpecularColorKeys, Step);
	mAttenuation = CalculateKey(mAttenuationKeys, Step);
	mSpotCutoff = CalculateKey(mSpotCutoffKeys, Step);
	mSpotExponent = CalculateKey(mSpotExponentKeys, Step);

	if (IsPointLight())
	{
		mWorldLight = lcMatrix44Identity();
		mWorldLight.SetTranslation(-mPosition);
	}
	else
	{
		lcVector3 FrontVector(mTargetPosition - mPosition);
		lcVector3 UpVector(1, 1, 1);

		if (fabs(FrontVector[0]) < fabs(FrontVector[1]))
		{
			if (fabs(FrontVector[0]) < fabs(FrontVector[2]))
				UpVector[0] = -(UpVector[1] * FrontVector[1] + UpVector[2] * FrontVector[2]);
			else
				UpVector[2] = -(UpVector[0] * FrontVector[0] + UpVector[1] * FrontVector[1]);
		}
		else
		{
			if (fabs(FrontVector[1]) < fabs(FrontVector[2]))
				UpVector[1] = -(UpVector[0] * FrontVector[0] + UpVector[2] * FrontVector[2]);
			else
				UpVector[2] = -(UpVector[0] * FrontVector[0] + UpVector[1] * FrontVector[1]);
		}

		mWorldLight = lcMatrix44LookAt(mPosition, mTargetPosition, UpVector);
	}
}

void lcLight::Render(View* View)
{
	float LineWidth = lcGetPreferences().mLineWidth;
	const lcMatrix44& ViewMatrix = View->mCamera->mWorldView;
	lcContext* Context = View->mContext;

	if (IsPointLight())
	{
		Context->SetWorldViewMatrix(lcMul(lcMatrix44Translation(mPosition), ViewMatrix));

		if (IsSelected(LC_LIGHT_SECTION_POSITION))
		{
			if (IsFocused(LC_LIGHT_SECTION_POSITION))
				lcSetColorFocused();
			else
				lcSetColorSelected();
		}
		else
			lcSetColorLight();

		RenderSphere();
	}
	else
	{
		if (IsSelected(LC_LIGHT_SECTION_POSITION))
		{
			Context->SetLineWidth(2.0f * LineWidth);
			if (IsFocused(LC_LIGHT_SECTION_POSITION))
				lcSetColorFocused();
			else
				lcSetColorSelected();
		}
		else
		{
			Context->SetLineWidth(LineWidth);
			lcSetColorLight();
		}

		RenderCone(ViewMatrix);

		if (IsSelected(LC_LIGHT_SECTION_TARGET))
		{
			Context->SetLineWidth(2.0f * LineWidth);
			if (IsFocused(LC_LIGHT_SECTION_TARGET))
				lcSetColorFocused();
			else
				lcSetColorSelected();
		}
		else
		{
			Context->SetLineWidth(LineWidth);
			lcSetColorLight();
		}

		RenderTarget();

		Context->SetWorldViewMatrix(ViewMatrix);

		Context->SetLineWidth(LineWidth);
		lcSetColorLight();

		lcVector3 Line[2] = { mPosition, mTargetPosition };
		glVertexPointer(3, GL_FLOAT, 0, Line);

		glDrawArrays(GL_LINES, 0, 2);

		if (IsSelected())
		{
			lcMatrix44 ProjectionMatrix, LightMatrix;
			lcVector3 FrontVector(mTargetPosition - mPosition);
			lcVector3 UpVector(1, 1, 1);
			float Length = FrontVector.Length();

			if (fabs(FrontVector[0]) < fabs(FrontVector[1]))
			{
				if (fabs(FrontVector[0]) < fabs(FrontVector[2]))
					UpVector[0] = -(UpVector[1] * FrontVector[1] + UpVector[2] * FrontVector[2]);
				else
					UpVector[2] = -(UpVector[0] * FrontVector[0] + UpVector[1] * FrontVector[1]);
			}
			else
			{
				if (fabs(FrontVector[1]) < fabs(FrontVector[2]))
					UpVector[1] = -(UpVector[0] * FrontVector[0] + UpVector[2] * FrontVector[2]);
				else
					UpVector[2] = -(UpVector[0] * FrontVector[0] + UpVector[1] * FrontVector[1]);
			}

			LightMatrix = lcMatrix44LookAt(mPosition, mTargetPosition, UpVector);
			LightMatrix = lcMatrix44AffineInverse(LightMatrix);
			ProjectionMatrix = lcMatrix44Perspective(2 * mSpotCutoff, 1.0f, 0.01f, Length);
			ProjectionMatrix = lcMatrix44Inverse(ProjectionMatrix);
			Context->SetWorldViewMatrix(lcMul(ProjectionMatrix, lcMul(LightMatrix, ViewMatrix)));

			// Draw the light cone.
			float Verts[16][3] =
			{
				{  0.5f,   1.0f,  1.0f },
				{  1.0f,   0.5f,  1.0f },
				{  1.0f,  -0.5f,  1.0f },
				{  0.5f,  -1.0f,  1.0f },
				{ -0.5f,  -1.0f,  1.0f },
				{ -1.0f,  -0.5f,  1.0f },
				{ -1.0f,   0.5f,  1.0f },
				{ -0.5f,   1.0f,  1.0f },
				{  1.0f,   1.0f, -1.0f },
				{  0.75f,  0.75f, 1.0f },
				{ -1.0f,   1.0f, -1.0f },
				{ -0.75f,  0.75f, 1.0f },
				{ -1.0f,  -1.0f, -1.0f },
				{ -0.75f, -0.75f, 1.0f },
				{  1.0f,  -1.0f, -1.0f },
				{  0.75f, -0.75f, 1.0f }
			};

			glVertexPointer(3, GL_FLOAT, 0, Verts);
			glDrawArrays(GL_LINE_LOOP, 0, 8);
			glDrawArrays(GL_LINES, 8, 8);
		}
	}
}

void lcLight::RenderCone(const lcMatrix44& ViewMatrix)
{
	lcVector3 FrontVector(mTargetPosition - mPosition);
	lcVector3 UpVector(1, 1, 1);
	float Length = FrontVector.Length();

	if (fabs(FrontVector[0]) < fabs(FrontVector[1]))
	{
		if (fabs(FrontVector[0]) < fabs(FrontVector[2]))
			UpVector[0] = -(UpVector[1] * FrontVector[1] + UpVector[2] * FrontVector[2]);
		else
			UpVector[2] = -(UpVector[0] * FrontVector[0] + UpVector[1] * FrontVector[1]);
	}
	else
	{
		if (fabs(FrontVector[1]) < fabs(FrontVector[2]))
			UpVector[1] = -(UpVector[0] * FrontVector[0] + UpVector[2] * FrontVector[2]);
		else
			UpVector[2] = -(UpVector[0] * FrontVector[0] + UpVector[1] * FrontVector[1]);
	}

	lcMatrix44 LightMatrix = lcMatrix44LookAt(mPosition, mTargetPosition, UpVector);
	LightMatrix = lcMatrix44AffineInverse(LightMatrix);
	LightMatrix.SetTranslation(lcVector3(0, 0, 0));

	lcMatrix44 LightViewMatrix = lcMul(LightMatrix, lcMul(lcMatrix44Translation(mPosition), ViewMatrix));

	glLoadMatrixf(LightViewMatrix);

	float verts[16*3];
	for (int i = 0; i < 8; i++)
	{
		verts[i*6] = verts[i*6+3] = (float)cos((float)i/4 * LC_PI) * 0.3f;
		verts[i*6+1] = verts[i*6+4] = (float)sin((float)i/4 * LC_PI) * 0.3f;
		verts[i*6+2] = 0.3f;
		verts[i*6+5] = -0.3f;
	}

	glVertexPointer(3, GL_FLOAT, 0, verts);
	glDrawArrays(GL_LINES, 0, 16);
	glVertexPointer(3, GL_FLOAT, 6*sizeof(float), verts);
	glDrawArrays(GL_LINE_LOOP, 0, 8);
	glVertexPointer(3, GL_FLOAT, 6*sizeof(float), &verts[3]);
	glDrawArrays(GL_LINE_LOOP, 0, 8);

	float Lines[4][3] =
	{
		{ -0.5f, -0.5f, -0.3f },
		{  0.5f, -0.5f, -0.3f },
		{  0.5f,  0.5f, -0.3f },
		{ -0.5f,  0.5f, -0.3f }
	};

	glVertexPointer(3, GL_FLOAT, 0, Lines);
	glDrawArrays(GL_LINE_LOOP, 0, 4);

	glLoadMatrixf(lcMul(lcMatrix44Translation(lcVector3(0, 0, -Length)), LightViewMatrix));
}

void lcLight::RenderTarget()
{
	float box[24][3] =
	{
		{  0.2f,  0.2f,  0.2f }, { -0.2f,  0.2f,  0.2f },
		{ -0.2f,  0.2f,  0.2f }, { -0.2f, -0.2f,  0.2f },
		{ -0.2f, -0.2f,  0.2f }, {  0.2f, -0.2f,  0.2f },
		{  0.2f, -0.2f,  0.2f }, {  0.2f,  0.2f,  0.2f },
		{  0.2f,  0.2f, -0.2f }, { -0.2f,  0.2f, -0.2f },
		{ -0.2f,  0.2f, -0.2f }, { -0.2f, -0.2f, -0.2f },
		{ -0.2f, -0.2f, -0.2f }, {  0.2f, -0.2f, -0.2f },
		{  0.2f, -0.2f, -0.2f }, {  0.2f,  0.2f, -0.2f },
		{  0.2f,  0.2f,  0.2f }, {  0.2f,  0.2f, -0.2f },
		{ -0.2f,  0.2f,  0.2f }, { -0.2f,  0.2f, -0.2f },
		{ -0.2f, -0.2f,  0.2f }, { -0.2f, -0.2f, -0.2f },
		{  0.2f, -0.2f,  0.2f }, {  0.2f, -0.2f, -0.2f }
	};

	glVertexPointer(3, GL_FLOAT, 0, box);
	glDrawArrays(GL_LINES, 0, 24);
}

void lcLight::RenderSphere()
{
	const int Slices = 6;
	const int NumIndices = 3 * Slices + 6 * Slices * (Slices - 2) + 3 * Slices;
	const int NumVertices = (Slices - 1) * Slices + 2;
	const float Radius = 0.2f;
	lcVector3 Vertices[NumVertices];
	lcuint16 Indices[NumIndices];

	lcVector3* Vertex = Vertices;
	lcuint16* Index = Indices;

	*Vertex++ = lcVector3(0, 0, Radius);

	for (int i = 1; i < Slices; i++ )
	{
		float r0 = Radius * sinf(i * (LC_PI / Slices));
		float z0 = Radius * cosf(i * (LC_PI / Slices));

		for (int j = 0; j < Slices; j++)
		{
			float x0 = r0 * sinf(j * (LC_2PI / Slices));
			float y0 = r0 * cosf(j * (LC_2PI / Slices));

			*Vertex++ = lcVector3(x0, y0, z0);
		}
	}

	*Vertex++ = lcVector3(0, 0, -Radius);

	for (int i = 0; i < Slices - 1; i++ )
	{
		*Index++ = 0;
		*Index++ = 1 + i;
		*Index++ = 1 + i + 1;
	}

	*Index++ = 0;
	*Index++ = 1;
	*Index++ = 1 + Slices - 1;

	for (int i = 0; i < Slices - 2; i++ )
	{
		int Row1 = 1 + i * Slices;
		int Row2 = 1 + (i + 1) * Slices;

		for (int j = 0; j < Slices - 1; j++ )
		{
			*Index++ = Row1 + j;
			*Index++ = Row2 + j + 1;
			*Index++ = Row2 + j;

			*Index++ = Row1 + j;
			*Index++ = Row1 + j + 1;
			*Index++ = Row2 + j + 1;
		}

		*Index++ = Row1 + Slices - 1;
		*Index++ = Row2 + 0;
		*Index++ = Row2 + Slices - 1;

		*Index++ = Row1 + Slices - 1;
		*Index++ = Row2 + 0;
		*Index++ = Row1 + 0;
	}

	for (int i = 0; i < Slices - 1; i++ )
	{
		*Index++ = (Slices - 1) * Slices + 1;
		*Index++ = (Slices - 1) * (Slices - 1) + i;
		*Index++ = (Slices - 1) * (Slices - 1) + i + 1;
	}

	*Index++ = (Slices - 1) * Slices + 1;
	*Index++ = (Slices - 1) * (Slices - 1) + (Slices - 2) + 1;
	*Index++ = (Slices - 1) * (Slices - 1);

	glVertexPointer(3, GL_FLOAT, 0, Vertices);
	glDrawElements(GL_TRIANGLES, NumIndices, GL_UNSIGNED_SHORT, Indices);
}

bool lcLight::Setup(int LightIndex)
{
	GLenum LightName = (GLenum)(GL_LIGHT0 + LightIndex);

	if (mState & LC_LIGHT_DISABLED)
		return false;

	glEnable(LightName);

	glLightfv(LightName, GL_AMBIENT, mAmbientColor);
	glLightfv(LightName, GL_DIFFUSE, mDiffuseColor);
	glLightfv(LightName, GL_SPECULAR, mSpecularColor);

	if (!IsDirectionalLight())
	{
		glLightf(LightName, GL_CONSTANT_ATTENUATION, mAttenuation[0]);
		glLightf(LightName, GL_LINEAR_ATTENUATION, mAttenuation[1]);
		glLightf(LightName, GL_QUADRATIC_ATTENUATION, mAttenuation[2]);

		lcVector4 Position(mPosition, 1.0f);
		glLightfv(LightName, GL_POSITION, Position);
	}
	else
	{
		lcVector4 Position(mPosition, 0.0f);
		glLightfv(LightName, GL_POSITION, Position);
	}

	if (IsPointLight())
	{
		glLightf(LightName, GL_SPOT_CUTOFF, 180.0f);
	}
	else if (IsSpotLight())
	{
		lcVector3 Dir(mTargetPosition - mPosition);
		Dir.Normalize();

		glLightf(LightName, GL_SPOT_CUTOFF, mSpotCutoff);
		glLightf(LightName, GL_SPOT_EXPONENT, mSpotExponent);
		glLightfv(LightName, GL_SPOT_DIRECTION, Dir);
	}

	return true;
}