#include "PerformanceGraph.h"
#include "glInterface.h"


PerformanceGraph::PerformanceGraph(int maxData): 
mMaxData(maxData), mCurrentIdx(0)
{
	mGraphColor[0] = 1.0f;
	mGraphColor[1] = 0.0f;
	mGraphColor[2] = 0.0f;
}

	
void PerformanceGraph::DrawBackGround()
{
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

	glColor4f(0.0f, 0.0f, 0.0f, 0.5f);

	// show a grid
	glBegin(GL_QUADS);
	glVertex3f(0, 0, 0.0f);
	glVertex3f(1, 0, 0.0f);
	glVertex3f(1, 1, 0.0f);
	glVertex3f(0, 1, 0.0f);
	glEnd();

	glDisable(GL_BLEND);
}


void PerformanceGraph::DrawGrid()
{
	glColor4f(0.0f, 1.0f, 0.0f, 1.0f);

	// show a grid
	glBegin(GL_LINE_LOOP);
	glVertex3f(0, 0, 0.0f);
	glVertex3f(1, 0, 0.0f);
	glVertex3f(1, 1, 0.0f);
	glVertex3f(0, 1, 0.0f);
	glEnd();
}


void PerformanceGraph::Draw()
{
	glPushAttrib(GL_ALL_ATTRIB_BITS);

	glLineWidth(2);
	glDisable(GL_DEPTH_TEST);
	//glDepthMask(true);

	glDisable(GL_LIGHTING);
	glDisable(GL_TEXTURE_2D);

	// init ortographic projection
	glMatrixMode(GL_PROJECTION);
	glPushMatrix();
	glLoadIdentity();

	gluOrtho2D(0, 1.0f, 0, 1.0f);

	glMatrixMode(GL_MODELVIEW);
	glPushMatrix();
	glLoadIdentity();
	
	glTranslatef(0.668f, 0.668f, 0.0f);
	glScalef(0.33f, 0.33f, 1.0f);

	DrawBackGround();
	DrawCurve();
	DrawGrid();

	glPopMatrix();
	
	// restore the projection matrix
	glMatrixMode(GL_PROJECTION);
	glPopMatrix();

	glMatrixMode(GL_MODELVIEW);

	glPopAttrib();
}


void PerformanceGraph::DrawCurve()
{
	const float scalex = 1.0f / mMaxData;
	const float scaley = 1.0f / 50.0f;

	glColor3fv(mGraphColor);

	glBegin(GL_LINE_STRIP);

	for (size_t i = 0; i < mData.size(); ++ i)
	{
		const float x = i * scalex;
		const float y = mData[i] * scaley;

		glVertex3f(x, y, 0.0f);
	}

	glEnd();

	// show a grid
	glBegin(GL_LINES);
	glVertex3f(mCurrentIdx * scalex, 0, 0.0f);
	glVertex3f(mCurrentIdx * scalex, 1, 0.0f);
	glEnd();
}


void PerformanceGraph::AddData(float data)
{
	if ((int)mData.size() < mMaxData)
		mData.push_back(data);
	else
		mData[mCurrentIdx]= data;

	mCurrentIdx = (mCurrentIdx + 1) % mMaxData;
}


void PerformanceGraph::Reset()
{
	mCurrentIdx = 0;
	mData.clear();
}


void PerformanceGraph::SetGraphColor(float *col)
{
	mGraphColor[0] = col[0];
	mGraphColor[1] = col[1];
	mGraphColor[2] = col[2];
}