source: GTP/trunk/App/Demos/Vis/FriendlyCulling/src/PerformanceGraph.cpp @ 2834

#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);

        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();

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

        glMatrixMode(GL_MODELVIEW);
        glPopMatrix();

        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];
}