game.c

/*Written by Fredrik Lundström and Michell Dib 2021 (c)*/

#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <pic32mx.h> 
#include "snake.h" //Project header file

int btns;
int speed = 1000; //Higher is slower

//We made premade apples since the time.h library would not work on the Uno32
int apple_x[] = {
    56,
    39,
    28,
    95,
    46,
    107,
    13,
    69,
    65,
    11,
    28,
    82
};

int apple_y[] = {
    10,
    29,
    20,
    9,
    15,
    3,
    21,
    27,
    11,
    17,
    8,
    12
};

void game(){ 
    snake_move(); //First we will call for the snake movements
    if(snake.y[0] == apple_y[score] && snake.x[0] == apple_x[score]){ //If we collide with apple
        eat_apple(); //Call eat_apple function
    }
    if((snake.y[0] == 32 || snake.y[0] == 0) || (snake.x[0] == 128 || snake.x[0] == 0)){ //If we collide with wall
        collision(); //Call collision function
    }
    create_snake(); //After movements are made we create the snake

    int k;
    for(k = snake.length - 1; k > 0; k--){ // This for loop check if the head will collide with any coordinate of the body
        if(snake.x[0] == snake.x[k] && snake.y[0] == snake.y[k])
            collision();
    }

    create_apple(); //Every frame we create an apple based on the score that changes the apples coordinates to any of the premade values.
    delay(speed);
}

void collision(){
    char score2[] = "X";
    score2[0] = score + '0'; //Here we make an integer to a string

    while(btns != 0b1000){ //While BTN4 is not pressed we will display the score and a game over string.
        clear_display();
        display_string(1, "GAME OVER SCORE: ");
        display_string(2, score2);
        display_update();
        translateToImage();
	    display_image(0, oled_display);
        btns = getbtns();
    }
    main(); //If BTN4 is pressed we jump back to main and the game will then restart. 
}


void create_snake(){ //Here we will print out the snake
    int i,j,k,x,y;
    for(k = 0; k < snake.length; k++){
        for(i = 0; i < 1; i++){ //These for-loops can change the size of the snake but we decided to go with one pixel
            for(j = 0; j < 1; j++){
                x = snake.x[k] + i;
                y = snake.y[k] + j;

                display[y][x] = 1; 
            }
        }
    }
}

void snake_move(){ //MOVEMENT FOR SNAKE

    btns = getbtns(); //Get buttons

    int i;
    for(i = snake.length - 1; i > 0; i--){ //This for loop will change the coordinates of every part of the snake so that the body will follow the head
        snake.x[i] = snake.x[i - 1];
        snake.y[i] = snake.y[i - 1];
    }
    
    if(snake.dir == 'R'){ //RIGHT
        snake.x[0] += 1;
    }
    if(snake.dir == 'D'){ //DOWN
        snake.y[0] += 1;
    }
    if(snake.dir == 'U'){ //UP
        snake.y[0] -= 1;
    }
    if(snake.dir == 'L'){ //LEFT
        snake.x[0] -= 1;
    }

    /*for(k = snake.length - 1; k > 0; k--){ // This for loop check if the head will collide with any coordinate of the body
        if(snake.x[0] == snake.x[k] && snake.y[0] == snake.y[k])
            collision();
    }*/

    //  SO THE UNO32 REMEMBER THE DIRECTION EVEN AFTER THE BUTTON IS RELEASED
    if(snake.dir != 'L'){
        if(btns == 0b0001){ //RIGHT
            snake.dir = 'R';
        }
    }
    if(snake.dir != 'U'){
        if(btns == 0b0010){ //DOWN
            snake.dir = 'D';
        }
    }
    if(snake.dir != 'D'){
        if(btns == 0b0100){ //UP
            snake.dir = 'U';
        }
    }
    if(snake.dir != 'R'){
        if(btns == 0b1000){ //LEFT
            snake.dir = 'L';
        }
    }
}

void create_apple(){
    //RANDOMIZE POSITION does not work :(
    display[apple_y[score]][apple_x[score]] = 1; //Display apple
}

void eat_apple(){
    snake.length++; //Increase length
    score++; //Increase score which will also give the apple new coordinates 
}

int getbtns(void){ //Get btns
    int btn = (PORTD >> 5) & 0x0007;
    btn = (btn << 1);
                                    //Since the buttons was set to bits 11 through 5 we will now
                                    //shift the bits 5 bits the right and check them with and operation
                                   //and then see if buttons 4,3 or 2 are active.  
                                   // & them with seven since it is 0b0111 and button 1 will then always be 0
    btn = ((PORTF >> 1) & 0x1) | btn;  //For some reason the first button is in the portf register                              
    return btn; //Return the active buttons as integer (active bits will be 1)
}