Document all the public ErrorCode constants.

These are from the official GLFW documentation at:

http://www.glfw.org/docs/latest/group__errors.html#gad44162d78100ea5e87cdd38426b8c7a1

1 files changed, 42 insertions, 4 deletions

diff --git a/error.go b/error.go
index a4f05fb..ea18b5b 100644
--- a/error.go
+++ b/error.go
@@ -22,11 +22,49 @@ const (
 	platformError    ErrorCode = C.GLFW_PLATFORM_ERROR     // A platform-specific error occurred that does not match any of the more specific categories.
 )
 
-// Error codes.
 const (
-	APIUnavailable     ErrorCode = C.GLFW_API_UNAVAILABLE     // GLFW could not find support for the requested client API on the system.
-	VersionUnavailable ErrorCode = C.GLFW_VERSION_UNAVAILABLE // The requested client API version is not available.
-	FormatUnavailable  ErrorCode = C.GLFW_FORMAT_UNAVAILABLE  // The clipboard did not contain data in the requested format.
+	// APIUnavailable is the error code used when GLFW could not find support
+	// for the requested client API on the system.
+	//
+	// The installed graphics driver does not support the requested client API,
+	// or does not support it via the chosen context creation backend. Below
+	// are a few examples.
+	//
+	// Some pre-installed Windows graphics drivers do not support OpenGL. AMD
+	// only supports OpenGL ES via EGL, while Nvidia and Intel only supports it
+	// via a WGL or GLX extension. OS X does not provide OpenGL ES at all. The
+	// Mesa EGL, OpenGL and OpenGL ES libraries do not interface with the
+	// Nvidia binary driver.
+	APIUnavailable ErrorCode = C.GLFW_API_UNAVAILABLE
+
+	// VersionUnavailable is the error code used when the requested OpenGL or
+	// OpenGL ES (including any requested profile or context option) is not
+	// available on this machine.
+	//
+	// The machine does not support your requirements. If your application is
+	// sufficiently flexible, downgrade your requirements and try again.
+	// Otherwise, inform the user that their machine does not match your
+	// requirements.
+	//
+	// Future invalid OpenGL and OpenGL ES versions, for example OpenGL 4.8 if
+	// 5.0 comes out before the 4.x series gets that far, also fail with this
+	// error and not GLFW_INVALID_VALUE, because GLFW cannot know what future
+	// versions will exist.
+	VersionUnavailable ErrorCode = C.GLFW_VERSION_UNAVAILABLE
+
+	// FormatUnavailable is the error code used for both window creation and
+	// clipboard querying format errors.
+	//
+	// If emitted during window creation, the requested pixel format is not
+	// supported. This means one or more hard constraints did not match any of
+	// the available pixel formats. If your application is sufficiently
+	// flexible, downgrade your requirements and try again. Otherwise, inform
+	// the user that their machine does not match your requirements.
+	//
+	// If emitted when querying the clipboard, the contents of the clipboard
+	// could not be converted to the requested format. You should ignore the
+	// error or report it to the user, as appropriate.
+	FormatUnavailable ErrorCode = C.GLFW_FORMAT_UNAVAILABLE
 )
 
 func (e ErrorCode) String() string {