class Main {
    
    static int division_tmp;
    static Array mem;
    static Array st;
    static int f;
    static boolean color;

    /** Initializes the library. */
    function void init_test() {
        var int a;
        let st = Array.new(16);
        let st[0] = 1;
        while (a < 15){
            let a = a + 1;
            let st[a] = st[a - 1] + st[a - 1];
        }
        let color = 1;
        return;
    }
    
   
    function void main(){
        do Main.init_test();
        do Main.test_drawPixel(256,128);
        do Main.test_drawPixel(255,128);
        do Main.test_drawPixel(257,128);
        do Main.test_changeColor(0);
        do Main.test_drawPixel(256,128);
        return;
    }
    function void test_changeColor(boolean x){
        let color = x;
        return;
    }
    function void test_clearScreen(){
        var int a;
        let a = 16384;
        while (a < 24575){
            let mem[a] = 0;
            let a = a + 1;
        }
        return;
    }
    function void test_drawRectangle(int x1, int y1, int x2, int y2){
        var int a, tmp;
        if (x1 > x2){
            let tmp = x1;
            let x1 = x2;
            let x2 = tmp;
        }
        if (y1 > y2){
            let tmp = y1;
            let y1 = y2;
            let y2 = tmp;
        }
        if((x1 < 0) | (x2 > 511) | (y1 < 0) | (y2 > 255)){
            do Sys.error(8);
        }
        while(a < y2){
            do Screen.drawLine(x1, y1 + a, x2, y1 + a);
            let a = a + 1;
        }
        return;    
    }
    function void test_drawCicle(int x, int y, int r){
        var int dy, dx, tmp;
        if(r > 181){
            do Sys.error(7);
        }
        let dy = - r;
        while (dy < r){
            let tmp = Math.sqrt((r * r) - (dy * dy));
            do Screen.drawLine(x - tmp, y + dy, x + tmp, y + dy);
            let dy = dy + 1;
        }
        return;
    }
    function  void test_drawLine_optimize(int x1, int y1, int x2, int y2){
        var int diff, dx, dy, a, b, tmp;
        if (x1 > x2){
            let tmp = x1;
            let x1 = x2;
            let x2 = tmp;
        }
        if (y1 > y2){
            let tmp = y1;
            let y1 = y2;
            let y2 = tmp;
        }
        if((x1 < 0) | (x2 > 511) | (y1 < 0) | (y2 > 255)){
            do Sys.error(8);
        }
        let dx = x2 - x1;
        let dy = y2 - y1;
        if (dx = 0){
            while(~(b > dy)){
                do Screen.drawPixel(x1, y1 + b);
                let b = b + 1;
            }
            return;
        }
        if (dy = 0){
            while(~(a > dx)){
                do Screen.drawPixel(x1 + a, y1);
                let a = a + 1;
            }
            return;
        }
        while ((~(a > dx)) & (~(b > dy))){
            do Screen.drawPixel(x1 + a, y1 + b);
            if (diff < 0){
                let a = a + 1;
                let diff = diff + dy;
            }
            else{
                let b = b + 1;
                let diff = diff - dx;               
            }
        }
        return;
    }
    
    function void test_drawPixel(int x, int y) {
        var int value, address, bit, mem_block;
        if ((x > 511) | (x < 0) | (y > 255) | (y < 0)){
            do Sys.error(7);
        }
        let mem_block = x / 16;
        let address = (32 * y) + mem_block + 16384;
        let value = mem[address];
        let bit = x - (mem_block * 16);
        if (color = 1){
            let mem[address] = st[bit] | value;
        }
        else{
            let mem[address] = (~st[bit])& value;
        }
        return;
    }
    

    function int test_multiply(int x, int y){
        var int sum, temp, y_comp, i, neg;
        let neg = ((x < 0) & (y > 0)) | ((x > 0) & (y < 0)); 
        let x = Math.abs(x);
        let y = Math.abs(y);
        if (x < y){
            let temp = x;
            let x = y;
            let y = temp;
        }
        if (y = 1){
            if(neg){
                return -x;
            }
            return x;
        }
        while((y_comp - 1) < (y - 1)){
            if ((st[i] & y) > 0) {
                let sum = sum + x;
                let y_comp = y_comp + st[i];
            }
            let x = x + x;
            let i = i + 1;
        }
        if(neg){
            let sum = -sum;
        }
        return sum;
    }
    function int test_max(int x, int y){
        if (x > y){
            return x;
        }
        return y;
    }
    
    function int test_min(int x, int y){
        if (x < y){
            return x;
        }
        return y;
    }
    function int test_sqrt(int x) {
        var int j, b, d, y;
        if (x < 0){
            do Sys.error(4);
            }
        let j = 7;
        while (j > -1){
            let d = y + st[j];
            let b = Main.test_multiply(d,d);
            if ((~(b > x)) & (b > 0)){
                let y = d;
            }
            let j = j - 1;
        }
        return y;
    }
    function int test_divide(int x, int y) {
        var int q, neg;
        if (f = 0){
            let division_tmp = 0;
            let neg = ((x < 0) & (y > 0)) | ((x > 0) & (y < 0)); 
            let x = Math.abs(x);  
            let y = Math.abs(y); 
            if (y = 0){
                do Sys.error(3);
            }
            let f = 1;
        }
        if ((y > x) | (y < 0)){
            return 0;
        }
        let q = test_divide(x, y + y);
        let f = 0;
        let q = Math.abs(q);
        if ((q & 1) = 1){
            let division_tmp = division_tmp + y + y;
        }
        if (x - division_tmp < y){
            if (neg){
                return -(q + q);
            }
            return q + q;
        }
        else{
            if (neg){
                return -(q + q + 1);
            }
            return q + q + 1;
        }
    }
    

    function int test_abs(int x) {
        if (x > 0){
            return x;
            }
        return -x;
    }

    function int test_peek(int x){
        return mem[x];
    }
    
    function void test_poke(int x, int y){
        let mem[x] = y;
        return;
    }
    
    function int test_dealloc_stolen(Array x){
        var int obj_add,b;
        let obj_add = x - 2;
        let b = obj_add[1];
        if (b[0] = 0){
            let obj_add[0] = obj_add[1] - obj_add -2;
        }
        else{
            let obj_add[0] = obj_add[1] - obj_add + b[0];
            if (b[1] = b +2){
                let obj_add[1] = obj_add + 2;
            }
            else{
                let obj_add[1] = b[1];
            }
        }
    }
    
    function void test_dealloc(Array o){
         var Array current_block;
         let current_block = 2048;
         let o[1]= current_block[1];
         let current_block[1] = o;
     }
     
    function int test_alloc(int size){
        var Array current_block;
        var int tmp;
        let current_block = 2048;
        if (size < 0){
            do Sys.error(5);
        }
        if (size = 0){
            let size = 1;
        }
        while (current_block[0] < (size + 2)) {
            let current_block = current_block[1];
        }
        let current_block[0] = current_block[0] - size - 2;
        let current_block = current_block + current_block[0] + 2;
        let current_block[0] = size;
        return current_block + 2;
    }
    
    function int test_alloc_stolen(int x){
        var Array curret_block, next_block;
        if (x < 0){
            do Sys.error(5);
        }
        if (x = 0){
            let x = 1;
        }
        let curret_block = 2048; 
        let curret_block[0] = 14334;
        let curret_block[1] = 2050;
        while ((curret_block < 16383) & (curret_block[0] < x)){ 
            let next_block = curret_block[1]; 
            if ((curret_block[0] = 0) | (next_block > 16382) | (next_block[0] = 0)){ // this sends directly out of while
                let curret_block = next_block; 
            }
            else {
                let curret_block[0] = curret_block[1] - curret_block + next_block[0];  // cb size =  
                if (next_block[1] = next_block + 2){ 
                    let curret_block[1] = curret_block + 2; 
                }
                else{
                    let curret_block[1] = next_block[1]; 
                }
            }
        }
        if ((curret_block + x) > 16379){
            do Sys.error(6);
        }
        if (curret_block[0] > (x + 2)){ // if current block fills the desired size perfectly
            let curret_block[x + 2] = curret_block[0] - x -2;
            if (curret_block[1] = curret_block + 2){
                let curret_block[x + 3] = curret_block + x + 4;
            }
            else{
                let curret_block[x + 3] = curret_block[1];
            }
        }
        let curret_block[0] = 0;
        return (curret_block + 2);
    }
    
    
}