#include "TextureModuleGrass.h"
#include "../Utility/Random.h"

using namespace TexGen;

TextureModuleGrass::TextureModuleGrass(void)
: TextureModuleBase("ProceduralGrass")
, m_NumberOfGrassIterations(100000)
{
	SetupParameters();
}

TextureModuleGrass::~TextureModuleGrass(void)
{
}

void TextureModuleGrass::DoModuleProcess()
{
	ColorValue green = ColorValue(0.231f, 0.294f, 0.007f, 1.0f);
	ColorValue darkGreen = ColorValue(0.407f, 0.396f, 0.180f, 1.0f);

	//Clear the whole image with a random color between our green and darkGreen color values
	for(int y = 0; y < m_HeightInPixels; ++y)
	{
		for(int x = 0; x < m_WidthInPixels; ++x)
		{
			float colorLerp = Util::Random::Range(0.0f, 1.0f);
			ColorValue resultColor = (green * colorLerp) + (darkGreen * (1.0f - colorLerp));

			SetPixel(x, y, resultColor);
		}
	}

	//Now we 'make' the grass by drawing a number of lines over the texture.
	for(int grassIteration = 0; grassIteration < m_NumberOfGrassIterations; ++grassIteration)
	{
		//We get a random start position
		float startX = Util::Random::Range(0.0f, (float)m_WidthInPixels);
		float startY = Util::Random::Range(0.0f, (float)m_HeightInPixels);

		//A random direction
		float directionX = Util::Random::Range(-1.0f, 1.0f);
		float directionY = Util::Random::Range(-1.0f, 1.0f);
		
		//A length
		int length = Util::Random::Range(2, 10);

		//And a random color
		float colorLerp = Util::Random::Range(0.0f, 1.0f);
		ColorValue grassColor = (green * colorLerp) + (darkGreen * (1.0f - colorLerp));

		for(int step = 0; step < length; ++step)
		{
			//Get the x and y coordinates for our current step.
			int x = (int)(startX + (directionX * (float)step));
			int y = (int)(startY + (directionY * (float)step));

			//Wrap our coordinates around the texture boundaries
			x = x % m_WidthInPixels;
			y = y % m_HeightInPixels;
			while(x < 0)
				x += m_WidthInPixels;
			while(y < 0)
				y += m_HeightInPixels;

			//Plot the pixel color
			SetPixel(x, y, grassColor);
		}
	}
}

void TextureModuleGrass::SetupParameters()
{
	//Register our parameters so we can edit them when the application is running.
	AddParameter("GrassIterations", &m_NumberOfGrassIterations);
}