#include "GraphingTexture.h"
#include "../OpenGLWindow/OpenGLInclude.h"
#include <assert.h>

GraphingTexture::GraphingTexture()
	: m_textureId(0),
	  m_width(0),
	  m_height(0)
{
}

GraphingTexture::~GraphingTexture()
{
	destroy();
}

void GraphingTexture::destroy()
{
	//TODO(erwincoumans) release memory etc...
	m_width = 0;
	m_height = 0;
	glDeleteTextures(1, (GLuint*)&m_textureId);
	m_textureId = 0;
}

bool GraphingTexture::create(int texWidth, int texHeight)
{
	m_width = texWidth;
	m_height = texHeight;
	glActiveTexture(GL_TEXTURE0);

	m_imageData.resize(texWidth * texHeight * 4);
	for (int y = 0; y < texHeight; ++y)
	{
		//					const int	t=y>>5;
		GLubyte* pi = &m_imageData[y * texWidth * 4];
		for (int x = 0; x < texWidth; ++x)
		{
			if (x >= y)  //x<2||y<2||x>253||y>253)
			{
				pi[0] = 0;
				pi[1] = 0;
				pi[2] = 255;
				pi[3] = 255;
			}
			else
			{
				pi[0] = 255;
				pi[1] = 0;
				pi[2] = 0;
				pi[3] = 255;
			}

			pi += 4;
		}
	}

	glGenTextures(1, (GLuint*)&m_textureId);

	uploadImageData();
	return true;
}

void GraphingTexture::uploadImageData()
{
	glBindTexture(GL_TEXTURE_2D, m_textureId);
	assert(glGetError() == GL_NO_ERROR);

	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, m_width, m_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, &m_imageData[0]);
	glGenerateMipmap(GL_TEXTURE_2D);

	assert(glGetError() == GL_NO_ERROR);
}