Introduction to Quartz and OpenGL for IOS development (106)

1 Preface
We have already learned that we can construct a wide variety of application interfaces. Then, some applications cannot be fully implemented simply by using the built-in components of UIKit. Sometimes the application needs custom plotting. In this case, we need to rely on two libraries to meet our drawing requirements. One library is Quartz 2D, which is part of the Core Graphics framework, and the other is OpenGL ES, which is a cross-platform Graphics library. OpenGL ES is a simplified version of OpenGL. Is a subset of it.

2. Details
Quartz 2D is a set of functions, data types and objects, which are used to draw views or images directly in memory. Quartz 2D regards the view or image being drawn as a virtual canvas and follows the so-called painter model ., Each drawing operation is applied to the canvas and above all previous drawing operations.

OpenGL ES is implemented in the form of a state machine. It does not allow operations that directly affect views, windows, or images. It maintains a virtual 3D world. When an object is added to this world, OpenGL ES tracks the state of all objects. OpenGL ES provides a virtual window into its world. You can add objects to the world and define the location of the virtual window relative to the world. Then, draw a view based on the configuration method and the relative positions of the objects in the middle, and present the view to the user through a window.

Quartz 2D only supports 2D plotting.

OpenGL ES provides 2D and 3D plotting tools.

3 conclusion
The above is a general introduction of the two drawing frameworks. In the next section, we will enter the magical world of drawing, Are u ready?