screen_fs.c

static const char* screen_fs = "#version 330 core\n"
"\n"
"in vec2 TexCoords;\n"
"out vec4 FragColor;\n"
"\n"
"uniform sampler2D screenTexture;\n"
"\n"
"void main()\n"
"{\n"
"  FragColor = texture(screenTexture, TexCoords);\n"
"}\n"
;