glfw: add C -> Zig error translation

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>

glfw/src/errors.zig

@@ -0,0 +1,104 @@
+//! Errors
+
+const c = @cImport(@cInclude("GLFW/glfw3.h"));
+
+/// Errors that GLFW can produce.
+const Error = error{
+    /// GLFW has not been initialized.
+    ///
+    /// This occurs if a GLFW function was called that must not be called unless the library is
+    /// initialized.
+    NotInitialized,
+
+    /// No context is current for this thread.
+    ///
+    /// This occurs if a GLFW function was called that needs and operates on the current OpenGL or
+    /// OpenGL ES context but no context is current on the calling thread. One such function is
+    /// glfw.SwapInterval.
+    NoCurrentContext,
+
+    /// One of the arguments to the function was an invalid enum value.
+    ///
+    /// One of the arguments to the function was an invalid enum value, for example requesting
+    /// glfw.red_bits with glfw.getWindowAttrib.
+    InvalidEnum,
+
+    /// One of the arguments to the function was an invalid value.
+    ///
+    /// One of the arguments to the function was an invalid value, for example requesting a
+    /// non-existent OpenGL or OpenGL ES version like 2.7.
+    ///
+    /// Requesting a valid but unavailable OpenGL or OpenGL ES version will instead result in a
+    /// glfw.Error.VersionUnavailable error.
+    InvalidValue,
+
+    /// A memory allocation failed.
+    OutOfMemory,
+
+    /// GLFW could not find support for the requested API on the system.
+    ///
+    /// The installed graphics driver does not support the requested 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 support it via a WGL or GLX extension. macOS
+    /// does not provide OpenGL ES at all. The Mesa EGL, OpenGL and OpenGL ES libraries do not
+    /// interface with the Nvidia binary driver. Older graphics drivers do not support Vulkan.
+    APIUnavailable,
+
+    /// The requested OpenGL or OpenGL ES version (including any requested context or framebuffer
+    /// hints) 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.Error.InvalidValue,
+    /// because GLFW cannot know what future versions will exist.
+    VersionUnavailable,
+
+    /// A platform-specific error occurred that does not match any of the more specific categories.
+    ///
+    /// A bug or configuration error in GLFW, the underlying operating system or its drivers, or a
+    /// lack of required resources. Report the issue to our [issue tracker](https://github.com/glfw/glfw/issues).
+    PlatformError,
+
+    /// The requested format is not supported or available.
+    ///
+    /// If emitted during window creation, the requested pixel format is not supported.
+    ///
+    /// If emitted when querying the clipboard, the contents of the clipboard could not be
+    /// converted to the requested format.
+    ///
+    /// If emitted during window creation, 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, ignore the error or report it to the user, as
+    /// appropriate.
+    FormatUnavailable,
+
+    /// The specified window does not have an OpenGL or OpenGL ES context.
+    ///
+    /// A window that does not have an OpenGL or OpenGL ES context was passed to a function that
+    /// requires it to have one.
+    NoWindowContext,
+};
+
+fn convertError(e: int) ?Error {
+    return switch (e) {
+        c.GLFW_NO_ERROR => null,
+        c.GLFW_NOT_INITIALIZED => Error.NotInitialized,
+        c.GLFW_NO_CURRENT_CONTEXT => Error.NoCurrentContext,
+        c.GLFW_INVALID_ENUM => Error.InvalidEnum,
+        c.GLFW_INVALID_VALUE => Error.InvalidValue,
+        c.GLFW_OUT_OF_MEMORY => Error.OutOfMemory,
+        c.GLFW_API_UNAVAILABLE => Error.APIUnavailable,
+        c.GLFW_VERSION_UNAVAILABLE => Error.VersionUnavailable,
+        c.GLFW_PLATFORM_ERROR => Error.PlatformError,
+        c.GLFW_FORMAT_UNAVAILABLE => Error.FormatUnavailable,
+        c.GLFW_NO_WINDOW_CONTEXT => Error.NoWindowContext,
+    };
+}

glfw/src/main.zig

@@ -4,6 +4,7 @@ const testing = std.testing;
 const c = @cImport(@cInclude("GLFW/glfw3.h"));
 
 pub usingnamespace @import("consts.zig");
+pub usingnamespace @import("errors.zig");
 
 pub const action = @import("action.zig");
 pub const gamepad_axis = @import("gamepad_axis.zig");