OpenGL 加载透明纹理

一、编译LPNG，ZLIB

依然是以前的老一套，在此不作过多赘述
将编译好的


加到工程中

可以参考https://blog.youkuaiyun.com/liuyez123/article/details/50629906

二、读取PNG

LPNG有示例，我直接拿来用了

image

namespace image{
   
   

	class png {
   
   
	public:
		png();
		~png();

		long load(const ::std::string &path);

	public:

		int width;
		int height;
		png_byte color_type;
		png_byte bit_depth;
		std::unique_ptr<unsigned char> data;
	};
}

long image::png::load(const ::std::string &path)
{
   
   
	unsigned char header[8];    // 8 is the maximum size that can be checked
	int x, y;
	png_structp png_ptr;
	png_infop info_ptr;
	int number_of_passes;

	/* open file and test for it being a png */
	FILE *fp;
	fopen_s(&fp, path.c_str(), "rb");
	if (!fp)
		return -1;
	fread(header, 1, 8, fp);
	if (png_sig_cmp(header, 0<