自上而下的射手。 我如何使子弹朝玩家瞄准的方向射击？

Question

I have a player made out of rectangles. I currently have it so that it always aims towards the mouse. I would like the player to be able to fire the bullets straight towards the mouse but I am unsure of what equation I would use to make the bullet move the correct amount along the x and y so that it meets the point it is aimed at.

This is what I currently have for the player.

public void playerImage(Graphics g) {
    Graphics2D g2d = (Graphics2D) g;
    theta = Math.atan2(playerY - InputHandler.mouseY + playerHeight / 2,
            playerX - InputHandler.mouseX + playerWidth / 2) - Math.PI / 2;
    g2d.rotate(theta, playerX + playerWidth / 2, playerY + playerHeight / 2);
    g2d.setColor(Color.blue.darker());
    // Main body
    g2d.drawRect(playerX, playerY, playerWidth, playerHeight);
    // Left arm
    g2d.drawRect(playerX - playerWidth / 2, playerY, playerWidth / 2,
            playerHeight);
    g2d.fillRect(playerX - playerWidth / 2, playerY, playerWidth / 2,
            playerHeight);
    // Right arm
    g2d.drawRect(playerX + playerWidth, playerY, playerWidth / 2,
            playerHeight);
    g2d.fillRect(playerX + playerWidth, playerY, playerWidth / 2,
            playerHeight);
    g2d.setColor(Color.red);
    g2d.fillRect(playerX, playerY, playerWidth, playerHeight);

}

Answer 1

Using the point where the player is located and the point where the bullet should go, you can define a line that goes through them. This will give you an equation like f(x) = a*x + b, which then you can use to calculate your coordinates for the path.

Check also the wiki page .