c - SDL 相对位置

Question

我有一个关于 SDL Surface 光标的理论问题。 如果我想在屏幕上显示 surface_A，我将使用通过 SDL_Rectcursor; 创建的光标，并将其与 SDL_BlitSurface(); 一起使用。 光标将包含相对于窗口左上角的位置。

但是如果我想在surface_A内显示surface_B，我是否必须指示相对于窗口左上角或surface_A左上角的光标？

Answer 1

您可能对光标的相对位置做出了一些错误的假设。链接位置有一套非常好的、详细的教程，可以帮助您解决问题...

来自 HERE ...

Using the first tutorial as our base, we'll delve more into the world of SDL surfaces. As I attempted to explain in the last lesson, SDL Surfaces are basically images stored in memory. Imagine we have a blank 320x240 pixel surface. Illustrating the SDL coordinate system, we have something like this:

This coordinate system is quite different than the normal one you are familiar with. Notice how the Y coordinate increases going down, and the X coordinate increases going right. Understanding the SDL coordinate system is important in order to properly draw images on the screen.

一些可能有助于澄清的附加术语:

SDL Window :您可以将其视为物理像素，或您的显示器。
SDL Renderer :控制在该窗口中创建的内容的属性/设置。