GK/QT/triangle-textures/mywindow.cpp

// Dolaczamy plik naglowkowy naszej klasy MyWindow
#include "mywindow.h"

// Dolaczamy plik naglowkowy zawierajacy definicje GUI
// Plik ten jest generowany automatycznie
// z pliku XML "mywindow.ui"
#include "ui_mywindow.h"

#include <cmath>
#include <QColor>
#include <QDebug>
#include <QColorDialog>
#include <iostream>
#include <float.h> // for float,double macros
#include <string.h>
#include <stack>
#include <vector>

#define PI 3.1415

std::vector<float> matrixMul(std::vector<float> p, std::vector<float> m)
{
    std::vector<float> res(3);
    for(int i = 0; i < 3; i++)
    {
        res.push_back(0);
        for(int j = 0; j < 3; j++)
        {
            res[i] += m[i * 3 + j] * p[j];
        }
    }
    return res;
}

std::vector<float> matrixMul3x3(std::vector<float> m1, std::vector<float> m2)
{
    std::vector<float> res(9, 0);
    for(int i = 0; i < 3; i++)
    {
        for(int j = 0; j < 3; j++)
        {
            for(int k = 0; k < 3; k++)
            {
                res[i * 3 + j] += m1[i * 3 + k] * m2[k * 3 + j];
            }
        }
    }
    return res;
}


QColor mul(float v, QColor c){
    int red = (int)(c.red() * v);
    if(red > 255) red = 255;
    int green = (int)(c.green() * v);
    if(green > 255) green = 255;
    int blue = (int)(c.blue() * v);
    if(blue > 255) blue = 255;
    int alpha = (int)(c.alpha() * v);
    if(alpha > 255) alpha = 255;
    return QColor(red, green, blue, alpha);
}

QColor add(QColor c1, QColor c2){
    int red = (int)(c1.red() + c2.red());
    if(red > 255) red = 255;
    int green = (int)(c1.green() + c2.green());
    if(green > 255) green = 255;
    int blue = (int)(c1.blue() + c2.blue());
    if(blue > 255) blue = 255;
    int alpha = (int)(c1.alpha() + c2.alpha());
    if(alpha > 255) alpha = 255;
    return QColor(red, green, blue, alpha);
}
// Definicja konstruktora, wywolujemy najpierw
// konstruktor klasy nadrzednej, nastepnie tworzymy
// obiekt klasy Ui_MyWindow reprezentujacy GUI
MyWindow::MyWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MyWindow)
{
    // Wywolujemy funkcje tworzaca elementy GUI
    // Jej definicja znajduje sie w pliku "ui_mywindow.h"
    ui->setupUi(this);

    // Pobieramy wymiary i wspolrzedne lewego gornego naroznika ramki
    // i ustawiamy wartosci odpowiednich pol
    // Uwaga: ramke "rysujFrame" wykorzystujemy tylko do
    // wygodnego ustaiwenia tych wymiarow. Rysunek bedziemy wyswietlac
    // bezposrednio w glownym oknie aplikacji.
    szer = ui->frame1->width();
    wys = ui->frame1->height();
    poczX1 = ui->frame1->x();
    poczY1 = ui->frame1->y();
    poczX2 = ui->frame2->x();
    poczY2 = ui->frame2->y();

    // Tworzymy obiekt klasy QImage, o odpowiedniej szerokosci
    // i wysokosci. Ustawiamy format bitmapy na 32 bitowe RGB
    // (0xffRRGGBB).
    img = new QImage(szer,wys,QImage::Format_RGB32);
    f1_img = new QImage(szer,wys,QImage::Format_RGB32);
    f2_img = new QImage(szer,wys,QImage::Format_RGB32);

    loaded_img1 = new QImage("/Users/dawidpietrykowski/Desktop/projects/umk/GK/QT/triangle-textures/c.jpg");

//    int width = loaded_img1->width();
//    int height = loaded_img1->height();
//    for(int x = 0; x < width; x++)
//        for(int y = 0; y < height; y++){
//            QColor color = GetPixel(loaded_img1, x, y);
//                DrawPixel(loaded_img1, x, y, QColor(255, 255, 255));
//        }

    for(int x = 0; x < szer; x++)
        for(int y = 0; y < wys; y++){
                float xw = (float) x / (float)szer;
                float yh = (float) y / (float) wys;
                QColor color = GetInterpolatedColor(loaded_img1, xw, yh);
                color.setAlpha(255);
                DrawPixel(img, x, y, color);
        }

    UpdateImage();

    update();
}

// Definicja destruktora
MyWindow::~MyWindow()
{
    delete ui;
}

// Funkcja (slot) wywolywana po nacisnieciu przycisku "Wyjscie" (exitButton)
// Uwaga: polaczenie tej funkcji z sygnalem "clicked"
// emitowanym przez przycisk jest realizowane
// za pomoca funkcji QMetaObject::connectSlotsByName(MyWindow)
// znajdujacej sie w automatycznie generowanym pliku "ui_mywindow.h"
// Nie musimy wiec sami wywolywac funkcji "connect"
void MyWindow::on_exitButton_clicked()
{
    // qApp to globalny wskaznik do obiektu reprezentujacego aplikacje
    // quit() to funkcja (slot) powodujaca zakonczenie aplikacji z kodem 0 (brak bledu)
    qApp->quit();
}

void MyWindow::UpdateImage(){
    ClearImage(f1_img);
    ClearImage(f2_img);

    memcpy(f1_img->bits(), img->bits(), szer * wys * 4);

    DrawTriangles();

    update();
}


QColor MyWindow::GetPixel(QImage* img, int x, int y){
    QColor res;
    int width = img->width();
    int height = img->height();
    if(x >= width || y >= height || x < 0 || y < 0)
        return res;

    unsigned char* ptr = img->bits();

    res.setBlue(ptr[width*4*y + 4*x]);
    res.setGreen(ptr[width*4*y + 4*x + 1]);
    res.setRed(ptr[width*4*y + 4*x + 2]);
    res.setAlpha(ptr[width*4*y + 4*x + 3]);

    return res;
}


QColor MyWindow::GetInterpolatedColor(QImage* im, float x, float y){
    float width = im->width();
    float height = im->height();
    float xw = (x * width);
    float yw = (y * height);
    int x_f = (int) (x * width);
    int y_f = (int) (y * height);
    int x_c = ceil(x * width);
    int y_c = ceil(y * height);
    float a = (xw - (float) x_f);
    float b = ((yw) - (float) y_f);

    QColor P1 = GetPixel(im, x_f, y_c);
    QColor P2 = GetPixel(im, x_c, y_c);
    QColor P3 = GetPixel(im, x_c, y_f);
    QColor P4 = GetPixel(im, x_f, y_f);

    QColor v1 = mul(1.0f - a, P1);
    QColor v2 = mul(a, P2);
    QColor v3 = mul(a, P3);
    QColor v4 = mul(1.0f - a, P4);
    QColor top = add(v1, v2);
    QColor bottom = add(v3, v4);
    QColor btop = mul(b, top);
    QColor bbottom = mul(1.0f - b, bottom);
    QColor res = add(btop, bbottom);

    return res;
}

void GetUVW(Point P, std::vector<Point> points, std::vector<float>& res){
    Point A = points[0];
    Point B = points[1];
    Point C = points[2];
    float x = P.x;
    float y = P.y;
    float v_top = (x - A.x) * (C.y - A.y) - (C.x - A.x) * (y - A.y);
    float v_bottom = (B.x - A.x) * (C.y - A.y) - (C.x - A.x) * (B.y - A.y);
    float w_top = (B.x - A.x) * (y - A.y) - (x - A.x) * (B.y - A.y);
    float w_bottom = (B.x - A.x) * (C.y - A.y) - (C.x - A.x) * (B.y - A.y);
    float v = v_top / v_bottom;
    float w = w_top / w_bottom;
    float u = 1.0f - v - w;
    res.push_back(u);
    res.push_back(v);
    res.push_back(w);
}

int MyWindow::FindPoint(int x, int y, float radius, int frame){
    Point src_point(x, y);
    float min_dist = FLT_MAX;
    int min_id = -1;
    std::vector<Point> points = frame == 0 ? points1 : points2;
    for(int i = 0; i < (int)points.size(); i++){
        float dist = (src_point - (Point)(points[i])).length();
        if(dist < min_dist && dist < radius){
            min_id = i;
            min_dist = dist;
        }
    }
    return min_id;
}

// Funkcja (slot) wywolywana po nacisnieciu przycisku myszy (w glownym oknie)
void MyWindow::mousePressEvent(QMouseEvent *event)
{
    // Pobieramy wspolrzedne punktu klikniecia
    int x = event->x();
    int y = event->y();

    // Sa to wspolrzedne wzgledem glownego okna,
    // Musimy odjac od nich wpolrzedne lewego gornego naroznika rysunku

    int x1 = x - poczX1;
    int y1 = y - poczY1;
    int x2 = x - poczX2;
    int y2 = y - poczY2;

    if(x1 < szer && y1 < wys && x1 >= 0 && y1 >= 0){
        tmp_point_id = FindPoint(x1, y1, 20, 0);
        if(tmp_point_id == -1 && points1.size() != 3){
            mode = Add;
        }else if(tmp_point_id != -1){
            mode = Move;
        }else{
            mode = None;
        }
        switch(mode){
        case Add:
            points1.push_back(Point(x1, y1));
            break;
        case Move:
            points1[tmp_point_id].x = x1;
            points1[tmp_point_id].y = y1;
            break;
        default:
            break;
        }
    }else if(x2 < szer && y2 < wys && x2 >= 0 && y2 >= 0){
        tmp_point_id = FindPoint(x2, y2, 20, 1);
        if(tmp_point_id == -1 && points2.size() != 3){
            mode = Add;
        }else if(tmp_point_id != -1){
            mode = Move;
        }else{
            mode = None;
        }
        switch(mode){
        case Add:
            points2.push_back(Point(x2, y2));
            break;
        case Move:
            points2[tmp_point_id].x = x2;
            points2[tmp_point_id].y = y2;
            break;
        default:
            break;
        }
    }else
        mode = None;

    UpdateImage();
}

void MyWindow::mouseMoveEvent(QMouseEvent *event)
{



    // Pobieramy wspolrzedne punktu klikniecia
    int x = event->x();
    int y = event->y();

    // Sa to wspolrzedne wzgledem glownego okna,
    // Musimy odjac od nich wpolrzedne lewego gornego naroznika rysunku

    int x1 = x - poczX1;
    int y1 = y - poczY1;
    int x2 = x - poczX2;
    int y2 = y - poczY2;

    if(x1 < szer && y1 < wys && x1 >= 0 && y1 >= 0){
        if(mode == Move){
            points1[tmp_point_id].x = x1;
            points1[tmp_point_id].y = y1;
        }
    }else if(x2 < szer && y2 < wys && x2 >= 0 && y2 >= 0){
        if(mode == Move){
            points2[tmp_point_id].x = x2;
            points2[tmp_point_id].y = y2;
        }
    }else
        mode = None;

    UpdateImage();
}

void MyWindow::DrawTriangles(){
    if(points1.size() == 3 && points2.size() == 3)
    for(int x = 0; x < szer; x++){
        for(int y = 0; y < wys; y++){
            std::vector<float> res;
            GetUVW(Point(x, y), points2, res);
            if(res[0] > 0 && res[1] > 0 && res[2] > 0){
                float u = res[0];
                float v = res[1];
                float w = res[2];
                Point A = points1[0];
                Point B = points1[1];
                Point C = points1[2];
                Point P2 = A * (1.0f - v - w) + B * v + C * w;
                DrawPixel(f2_img, x, y, GetInterpolatedColor(f1_img, (float) P2.x / szer, (float) P2.y / wys));
            }
//                DrawPixel(f1_img, x, y, QColor(255, 255, 255));
        }
    }

    Point lastPoint(0, 0);
    for(int i = 0; i < points1.size(); i+=1){
        DrawSquare(f1_img, points1[i].x, points1[i].y, 15, QColor(255, 0, 0));
        if(i != 0){
            DrawLine(f1_img, lastPoint.x, lastPoint.y, points1[i].x, points1[i].y);
        }
        lastPoint = points1[i];
    }
    if(points1.size() == 3)
        DrawLine(f1_img, points1[0].x, points1[0].y, points1[2].x, points1[2].y);

    for(int i = 0; i < points2.size(); i+=1){
        DrawSquare(f2_img, points2[i].x, points2[i].y, 15, QColor(255, 0, 0));
        if(i != 0){
            DrawLine(f2_img, lastPoint.x, lastPoint.y, points2[i].x, points2[i].y);
        }
        lastPoint = points2[i];
    }
    if(points2.size() == 3)
        DrawLine(f2_img, points2[0].x, points2[0].y, points2[2].x, points2[2].y);
}

void MyWindow::DrawSquare(QImage* im, int x, int y, int size, QColor color){
    size /= 2;
    for(int x1 = x - size; x1 < x + size; x1++){
        for(int y1 = y - size; y1 < y + size; y1++){
            if(x1 >= szer || y1 >= wys || x1 < 0 || y1 < 0)
                continue;
            DrawPixel(im, x1, y1, color);
        }
    }
}

// Funkcja "odmalowujaca" komponent
void MyWindow::paintEvent(QPaintEvent*)
{
    QPainter p(this);

//    UpdateImage();

    p.drawImage(poczX1,poczY1,*f1_img);
    p.drawImage(poczX2,poczY2,*f2_img);
}


void MyWindow::DrawPixel(QImage* im, int x, int y, QColor color){
    int width = im->width();
    int height = im->height();

    if(x >= width || y >= height || x < 0 || y < 0)
        return;

    unsigned char* ptr = im->bits();

    ptr[width*4*y + 4*x] = color.blue();
    ptr[width*4*y + 4*x + 1] = color.green();
    ptr[width*4*y + 4*x + 2] = color.red();
    ptr[width*4*y + 4*x + 3] = color.alpha();
}


void MyWindow::ClearImage(QImage *img){
    unsigned char* empty_val = (unsigned char*)malloc(4);
    empty_val[0] = 0;
    empty_val[1] = 0;
    empty_val[2] = 0;
    empty_val[3] = 255;
    unsigned char* ptr = img->bits();
    for(int i = 0; i < img->width(); i++){
        for(int j = 0; j < img->height(); j++){
            memcpy(ptr + 4 * (i + j * img->width()), empty_val, 4);
        }
    }
}


void MyWindow::DrawLine(QImage *im, int x1, int y1, int x2, int y2){
    if(x1 > x2){
        std::swap(x1, x2);
        std::swap(y1, y2);
    }
    float diff = x2 - x1;
    float a = diff != 0 ? (y2 - y1) / diff : FLT_MAX;

    QColor color(255, 255, 255, 255);

    if(abs(a) < 1.0f){
        for(int x = x1; x <= x2; x++){
            int x_form = x - x1;
            int y = a * x_form + y1;

            DrawPixel(im, x, y, color);
        }
    }
    else{
        if(y1 > y2){
            std::swap(x1, x2);
            std::swap(y1, y2);
        }
        float diff = x2 - x1;
        float a = diff != 0 ? (y2 - y1) / diff : FLT_MAX;
        for(int y = y1; y <= y2; y++){
            int y_form = y - y1;
            int x = ((float)(y_form) / a) + x1;

            DrawPixel(im, x, y, color);
        }
    }
}