我有一个存储在String值中的着色器：
var myShader =
" attribute vec4 a_position;" +
" void main() {" +
" gl_Position = a_position;" +
" }"
glShaderSource(shader,GLsizei(1),myShader,nil)
函数glShaderSource具有绑定签名：
func glShaderSource(shader: GLuint,count: GLsizei,string: UnsafePointer<UnsafePointer<GLchar>>,length: UnsafePointer<GLint>)
当我尝试直接将着色器String传递给glShaderSource时,我收到错误消息：
'String' is not convertible to 'UnsafePointer<UnsafePointer<GLchar>>'
如何正确传递String？ (xCode版本6.1(6A1052d))
