Question

我试图用javacript创建游戏。我的对象可以在画布中的任何4个方向移动。我试图让它沿对角线移动。有任何想法如何做到这一点。

  this.move = function () {
        counter++;
        // Determine if the action is move action
        if (KEY_STATUS.left || KEY_STATUS.right || KEY_STATUS.down || KEY_STATUS.up || KEY_STATUS.shift || KEY_STATUS.ctrl) {
            // The ship moved, so erase it's current image so it can
            // be redrawn in it's new location
            this.context.clearRect(this.x, this.y, this.width, this.height);
            // Update x and y according to the direction to move and
            // redraw the ship. Change the else if's to if statements
            // to have diagonal movement.
            if (KEY_STATUS.left) {
                this.x -= this.speed;
                if (this.x <= 0) // Keep player within the screen
                    this.x = 0;
            }
            else if (KEY_STATUS.right) {
                this.x += this.speed;
                if (this.x >= this.canvasWidth - this.width) this.x = this.canvasWidth - this.width;
            }
            else if (KEY_STATUS.up) {
                console.log(this.y);
                this.y -= this.speed;
                if (this.y < 0) this.y = 0;
                //                if (this.y <= this.canvasHeight / 4 * 3) this.y = this.canvasHeight / 4 * 3;
            }
            else if (KEY_STATUS.down) {
                this.y += this.speed;
                if (this.y >= this.canvasHeight - this.height) this.y = this.canvasHeight - this.height;
                console.log(this.canvasHeight);
                console.log(this.height);
            }
            else if (KEY_STATUS.shift) {
                this.speed += 2;
            }
            else if (KEY_STATUS.ctrl) {
                if (this.speed > 2) {
                    this.speed -= 2;
                }
                else {
                    this.speed = 2;
                }
            }
            // Finish by redrawing the ship
            this.draw();
        }
        if (KEY_STATUS.space && counter >= fireRate) {
            this.fire();
            counter = 0;
        }
    };

所以基本上对角移动它应该例如do;

this.x += this.speed;

但同时做：

this.y += this.speed;

Answer 1

你必须调整你的其他条件，如果条件为if，在它可以进入多个方向的情况下。

例如，您可能不想在同一侧上下或左右移动。因此，在这些情况下，您保持type: 'category', position: 'left', ticks: {条件。否则，只需将else if条件更改为if条件。

我假设您也无法同时按下else if和shift。

以下是您的代码的外观。

control

同时javascript canvas eventlistener 2按钮

1 个答案: