分析一下这段 opengl vertex的代码： // __multiversion__ // this signals the loading code to prepend either #version 100 or #version 300 es as apropriate. // to use centroid sampling we need to have version 300 es shaders, which requires changing: // attribute to in // varying to out when in vertex shaders or in when in fragment shaders // defining an out vec4 fragcolor and replacing uses of gl_fragcolor with fragcolor // texture2d to texture #if __version__ >= 300 #define attribute in #define varying out