algoBresenham.c

//
// Created by Mathi on 5/30/2024.
//

#include "algoBresenham.h"

void detectHigh(int x0, int y0, int x1, int y1, int** listOfBlock, SDL_Renderer* renderer, SDL_Point* point) {
    int deltaX, deltaY, D, xi, x;

    deltaX = x1 - x0;
    deltaY = y1 - y0;
    xi = 1;


    if (deltaX < 0) {
        xi = -1;
        deltaX = -deltaX;
    }

    D = 2*deltaX-deltaY;

    point->x = x0*(1920/SIZE);
    point->y = y0*(1080/SIZE);
    x = x0;


    for (int y = y0; y<y1; y++) {

        point->x = x*(1920/SIZE);
        point->y = y*(1080/SIZE);

        if (y >= SIZE || y < 0 || x >= SIZE || x < 0) {
            point->x = x0*(1920/SIZE);
            point->y = y0*(1080/SIZE);
            return;
        }
        if (listOfBlock[y][x] == 1) {
            return;
        }
        if (D > 0) {
            x += xi;
            D += 2*(deltaX-deltaY);
        } else {
            D += 2*deltaX;
        }
    }
}
void detectLow(int x0, int y0, int x1, int y1, int** listOfBlock, SDL_Renderer* renderer, SDL_Point* point) {
    int deltaX, deltaY, D, yi, y;

    deltaX = x1 - x0;
    deltaY = y1 - y0;
    yi = 1;

    if (deltaY < 0) {
        yi = -1;
        deltaY = -deltaY;
    }

    D = (2*deltaY)-deltaX;

    point->x = x0*(1920/SIZE);
    point->y = y0*(1080/SIZE);
    y = y0;

    for (int x = x0; x<x1; x++) {
        point->x = x*(1920/SIZE);
        point->y = y*(1080/SIZE);
        if (x >= SIZE || x < 0 || y >= SIZE || y < 0) {
            point->x = x0*(1920/SIZE);
            point->y = y0*(1080/SIZE);
            return;
        }
        if (listOfBlock[y][x] == 1) {
            return;
        }
        if (D > 0) {
            y += yi;
            D += 2*(deltaY-deltaX);
        } else {
            D += 2*deltaY;
        }
    }
}
void detect(int x0, int y0, int x1, int y1, int** listOfBlock, int angle, SDL_Renderer* renderer, SDL_Point* point) {
    if (abs(y1 - y0) < abs(x1 - x0)) {
        if (x0 > x1) {
            detectLow(x1, y1, x0, y0, listOfBlock, renderer, point);
        } else {
            detectLow(x0, y0, x1, y1, listOfBlock, renderer, point);
        }
    } else {

        if (y0 > y1) {
            detectHigh(x1, y1, x0, y0, listOfBlock, renderer, point);
        } else {
            detectHigh(x0, y0, x1, y1, listOfBlock, renderer, point);
        }
    }
}

double distance(int x0, int y0, double x1, double y1) {
    return sqrt(((x1-x0)*(x1-x0))+((y1-y0)*(y1-y0)));
}

int DDA(float x0, float y0, int x1, int y1, int listOfBlock[SIZE][SIZE], int angle, SDL_Renderer* renderer, SDL_FPoint* point) {
    int mx, my, mp, stop, ra;
    double aTan, nTan, rx2, ry2, rx1, ry1, xo, yo;
    ra = angle%360;
    while (ra < 0) {
        ra += 360;
    }
    stop = 0;
    aTan = -(1 / tanf(ra * PI / 180));
    if (ra > 180) {
        ry1 = y1 - 0.0001;
        rx1 = (y1 - ry1) * aTan + x1;
        yo = -1;
        xo = -yo * aTan;
    }
    if (ra < 180) {
        ry1 = y1 + 1;
        rx1 = (y1 - ry1) * aTan + x1;
        yo = 1;
        xo = -yo * aTan;
    }
    if (ra == 0) {
        rx1 = 2000;
        ry1 = y1;
        stop = SIZE * SIZE*3;
    }
    if (ra == 180) {
        rx1 = -2000;
        ry1 = y1;
        stop = SIZE * SIZE*3;
    }
    while (stop < SIZE * SIZE*3) {

        mx = (int) (rx1) / (1920 / SIZE);
        my = (int) (ry1) / (1080 / SIZE);
        //SDL_Log("%f %f %d\t %f %f\t %d %d", rx, ry, ra, x0, y0, mx, my);
        mp = my * SIZE + mx;
        if (mx >= 0 && mx < SIZE && my >= 0 && my < SIZE && listOfBlock[my][mx] > 0) {
            stop = SIZE * SIZE*3;
        } else {
            rx1 += xo;
            ry1 += yo;
            stop++;
        }

    }
    stop = 0;
    nTan = -tan(ra * PI / 180);
    if (ra > 90 && ra < 270) {
        rx2 = x1 - 0.0001;
        ry2 = (x1 - rx2) * nTan + y1;
        xo = -1;
        yo = -xo * nTan;
    }
    if (ra < 90 || ra > 270) {
        rx2 = x1 + 1;
        ry2 = (x1 - rx2) * nTan + y1;
        xo = 1;
        yo = -xo * nTan;
    }
    if (ra == 270) {
        rx2 = x1;
        ry2 = -2000;
        stop = SIZE * SIZE*3;
    }
    if (ra == 90) {
        rx2 = x1;
        ry2 = 2000;
        stop = SIZE * SIZE*3;
    }
    while (stop < SIZE * SIZE*3) {

        mx = (int) (rx2) / (1920 / SIZE);
        my = (int) (ry2) / (1080 / SIZE);
        //SDL_Log("%f %f %d\t %f %f\t %d %d\t %d", rx2, ry2, ra, x0, y0, mx, my, angle);
        mp = my * SIZE + mx;
        if (mx >= 0 && mx < SIZE && my >= 0 && my < SIZE && listOfBlock[my][mx] > 0) {
            stop = SIZE * SIZE*3;
        } else {
            rx2 += xo;
            ry2 += yo;
            stop++;
        }

    }
    //SDL_Log("");
    //SDL_Log("");
    //SDL_Log("");
    //SDL_SetRenderDrawColor(renderer, 0, 255, 255, 255);
    //SDL_RenderDrawLineF(renderer, x0, y0, rx1, ry1);
    //SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
    //SDL_RenderDrawLineF(renderer, x0, y0, rx2, ry2);
    //SDL_Log("%d %f %f", ra, aTan, nTan);
    if (distance(x1, y1, rx1, ry1) > distance(x1, y1, rx2, ry2)) {
        point->x = rx2;
        point->y = ry2;
        //SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
        //SDL_RenderDrawLineF(renderer, x1, y1, rx2, ry2);
        return listOfBlock[(int) (ry2) / (1080 / SIZE)][(int) (rx2) / (1920 / SIZE)];
    } else if (distance(x1, y1, rx1, ry1) < distance(x1, y1, rx2, ry2)) {
        point->x = rx1;
        point->y = ry1;
        //SDL_SetRenderDrawColor(renderer, 0, 255, 255, 255);
        //SDL_RenderDrawLineF(renderer, x1, y1, rx1, ry1);
        return listOfBlock[(int) (ry1) / (1080 / SIZE)][(int) (rx1) / (1920 / SIZE)]+10;
    }
    return -1;
}