我试图理解检查游戏中两个对象之间碰撞的代码 - 每像素碰撞。代码是:
/// <summary>
/// Determines if there is overlap of the non-transparent pixels
/// between two sprites.
/// </summary>
/// <param name="rectangleA">Bounding rectangle of the first sprite</param>
/// <param name="dataA">Pixel data of the first sprite</param>
/// <param name="rectangleB">Bouding rectangle of the second sprite</param>
/// <param name="dataB">Pixel data of the second sprite</param>
/// <returns>True if non-transparent pixels overlap; false otherwise</returns>
static bool IntersectPixels(Rectangle rectangleA, Color[] dataA,
Rectangle rectangleB, Color[] dataB)
{
// Find the bounds of the rectangle intersection
int top = Math.Max(rectangleA.Top, rectangleB.Top);
int bottom = Math.Min(rectangleA.Bottom, rectangleB.Bottom);
int left = Math.Max(rectangleA.Left, rectangleB.Left);
int right = Math.Min(rectangleA.Right, rectangleB.Right);
// Check every point within the intersection bounds
for (int y = top; y < bottom; y++)
{
for (int x = left; x < right; x++)
{
// Get the color of both pixels at this point
Color colorA = dataA[(x - rectangleA.Left) +
(y - rectangleA.Top) * rectangleA.Width];
Color colorB = dataB[(x - rectangleB.Left) +
(y - rectangleB.Top) * rectangleB.Width];
// If both pixels are not completely transparent,
if (colorA.A != 0 && colorB.A != 0)
{
// then an intersection has been found
return true;
}
}
}
// No intersection found
return false;
}
我找到了一些解释,但没有人解释最后几行:
// If both pixels are not completely transparent,
if (colorA.A != 0 && colorB.A != 0)
{
// then an intersection has been found
return true;
}
这是什么colorA.A
属性?为什么这个 if 语句确定发生了冲突?