//
// Computergraphik II
// Prof. Dr. Juergen Doellner
// Wintersemester 2001/2002
// 
// Rahmenprogramm fuer Aufgabenzettel 3
//
// Autoren: Florian Kirsch (kirsch@hpi.uni-potsdam.de)
//          Marc Nienhaus (nienhaus@hpi.uni-potsdam.de)
//          Juergen Doellner (doellner@hpi.uni-potsdam.de)
//

#include "cgraster.h"

CGRaster::CGRaster(int width, int height)
    : width_(width), height_(height) {
    raster_ = new Color[width_ * height_];
    clear();
}

CGRaster::~CGRaster() {
    delete [] raster_;
}

int CGRaster::width() const {
    return(width_);
}

int CGRaster::height() const {
    return(height_);
}

void CGRaster::clear(const Color& c) {
    for(int i = 0; i < width_ * height_; ++i) {
        raster_[i] = c;
    }
}

Color& CGRaster::getPixel(int x, int y) const {
    assert(x < width_);
    assert(y < height_);
    return raster_[x + y * width_];
}

void CGRaster::setPixel(int x, int y, const Color& c) {
    assert(x < width_);
    assert(y < height_);
    raster_[x + y * width_] = c;
}

void CGRaster::draw() const {
    int x,y;
    // draw pixels
    glColor3f(0, 0, 0);
    glBegin(GL_QUADS);
    for(y = 0; y < height(); ++y) {
        for(x = 0; x < width(); ++x) {
            const Color& c = getPixel(x,y);
            glColor4d(c[0], c[1], c[2], c[3]);
            glVertex2f(x    , y);
            glVertex2f(x + 1, y);
            glVertex2f(x + 1, y + 1);
            glVertex2f(x    , y + 1);
        }
    }
    glEnd();
        
    // draw grid
    glColor3f(0.5, 0.5, 0.5);
    glBegin(GL_LINES);
    for(x = 0; x <= width(); ++x) {
        glVertex2f(x, 0);
        glVertex2f(x, height());
    }
    for(y = 0; y <= height(); ++y) {
        glVertex2f(0, y);
        glVertex2f(width(), y);
    }
    glEnd();
}