Android NDK Beginner's Guide - Second Edition

Time for action – loading a PNG image

Now that libpng is compiled, let's read a real PNG file with it:

1. Edit jni/GraphicsManager.hpp and include the Resource header file.

   Create a new structure named TextureProperties containing:

   • A resource representing the texture asset
   • An OpenGL texture identifier (which is a kind of handle)
   • A width and a height

     ...
     #include "Resource.hpp"
     #include "Types.hpp"
     ...
     
     struct TextureProperties {
         Resource* textureResource;
         GLuint texture;
         int32_t width;
         int32_t height;
     };
     ...

2. Append a method loadTexture() to the GraphicsManager to read a PNG and load it into an OpenGL texture.

   Textures are saved in an mTextures array to cache and finalize them.

   ... class GraphicsManager { public: ... status start(); void stop(); status update(); ...