File content as of revision 14:36c306e26317:

#include "tank.h"
#include "globals.h"
#include "math.h"
#include "game_synchronizer.h"

extern Game_Synchronizer sync;


Tank::Tank(int sx, int sy, int width, int height, int color) {
    x = sx; y = sy;
    w = width; h = height;
    tank_color = color;
    barrel_theta = PI/4.0;
    barrel_length = w;
    wheel_rad = 2.0;
    draw();
}
int Tank::min_x(void) { 
    int barrel_extent = (-barrel_length*cos(barrel_theta) > w/2.0) ? barrel_length*cos(barrel_theta) + w/2.0 : 0;
    return x + barrel_extent;
}
    
int Tank::min_y(void) { return y; }
int Tank::max_x(void) { 
    int barrel_extent = (barrel_length*cos(barrel_theta) > w/2.0) ? barrel_length*cos(barrel_theta) : w/2.0;
    return x + w/2.0 + barrel_extent; 
}

int Tank::max_y(void) { 
    int barrel_extent = (sin(barrel_theta) > 0) ? barrel_length*sin(barrel_theta) : 0;
    return y + h + wheel_rad + barrel_extent;
}

void Tank::barrel_end(int& bx, int& by) {
    bx = x + w/2.0 + (barrel_length+1)*cos(barrel_theta);
    by = y+h+wheel_rad + (barrel_length+1)*sin(barrel_theta);
}

void Tank::reposition(int new_x, int new_y, float new_theta) {
    float old_theta = barrel_theta;
    int old_x = x;
    int old_y = y;
    int minx = min_x();
    int miny = min_y();
    int maxx = max_x();
    int maxy = max_y();
    
    x = new_x; y = new_y; barrel_theta = new_theta - (int)(new_theta/PI)*PI;
    
    if(min_x() < 0 || max_x() > 128) { 
        x = old_x; y = old_y; barrel_theta = old_theta;
        draw();
        return;
    }
    
    int right_edge = sync.read_pixel(min_x()-1, (min_y()+max_y())/2.0);
    int left_edge  = sync.read_pixel(max_x()+1, (min_y()+max_y())/2.0);
    
    if( ( right_edge != CONVERT_24_TO_16_BPP(SKY_COLOR) && new_x < old_x ) ||
        ( left_edge  != CONVERT_24_TO_16_BPP(SKY_COLOR) && new_x > old_x ) ) {
        x = old_x; y = old_y; barrel_theta = old_theta;
        draw();
        return;  
    } 
    
    
    sync.filled_rectangle(minx, miny, maxx, maxy, SKY_COLOR);
    sync.line(old_x + w/2.0, old_y+h+wheel_rad, old_x + w/2.0 + 1 + barrel_length*cos(old_theta), old_y+h + barrel_length*sin(old_theta), SKY_COLOR);
    draw();
}

void Tank::draw() {
    sync.line(x + w/2.0, y+h+wheel_rad, x + w/2.0 + barrel_length*cos(barrel_theta), y+h+wheel_rad + barrel_length*sin(barrel_theta), BLACK);
    sync.filled_rectangle(x, y+wheel_rad, x+w, y+h+wheel_rad, tank_color);
    sync.filled_circle(x+wheel_rad, y+wheel_rad, wheel_rad, BLACK);
    sync.filled_circle(x+w-wheel_rad, y+wheel_rad, wheel_rad, BLACK);
}