Merge pull request #532 from tomaka/precise-errors

Precise errors

6 files changed, 36 insertions, 23 deletions

diff --git a/src/api/cocoa/mod.rs b/src/api/cocoa/mod.rs
index 332244e..5ea57ae 100644
--- a/src/api/cocoa/mod.rs
+++ b/src/api/cocoa/mod.rs
@@ -335,7 +335,7 @@ impl Window {
 
         match builder.gl_robustness {
             Robustness::RobustNoResetNotification | Robustness::RobustLoseContextOnReset => {
-                return Err(CreationError::NotSupported);
+                return Err(CreationError::RobustnessNotSupported);
             },
             _ => ()
         }
@@ -512,11 +512,11 @@ impl Window {
             },
             (_, Some((1 ... 2, _)), Some(GlProfile::Core)) |
             (_, Some((3 ... 4, _)), Some(GlProfile::Compatibility)) =>
-                return Err(CreationError::NotSupported),
+                return Err(CreationError::OpenGlVersionNotSupported),
             (_, Some((1 ... 2, _)), _) => NSOpenGLProfileVersionLegacy as u32,
             (_, Some((3, 0 ... 2)), _) => NSOpenGLProfileVersion3_2Core as u32,
             (_, Some((3 ... 4, _)), _) => NSOpenGLProfileVersion4_1Core as u32,
-            _ => return Err(CreationError::NotSupported),
+            _ => return Err(CreationError::OpenGlVersionNotSupported),
         };
 
         // NOTE: OS X no longer has the concept of setting individual
@@ -603,7 +603,7 @@ impl Window {
                     Err(CreationError::NotSupported)
                 }
             } else {
-                Err(CreationError::NotSupported)
+                Err(CreationError::NoAvailablePixelFormat)
             }
         }
     }
diff --git a/src/api/egl/mod.rs b/src/api/egl/mod.rs
index d22c009..328a11e 100644
--- a/src/api/egl/mod.rs
+++ b/src/api/egl/mod.rs
@@ -68,7 +68,7 @@ impl Context {
                         } else if egl.BindAPI(ffi::egl::OPENGL_ES_API) != 0 {
                             (None, Api::OpenGlEs)
                         } else {
-                            return Err(CreationError::NotSupported);
+                            return Err(CreationError::OpenGlVersionNotSupported);
                         }
                     } else {
                         (None, Api::OpenGlEs)
@@ -77,21 +77,21 @@ impl Context {
                 GlRequest::Specific(Api::OpenGlEs, version) => {
                     if egl_version >= (1, 2) {
                         if egl.BindAPI(ffi::egl::OPENGL_ES_API) == 0 {
-                            return Err(CreationError::NotSupported);
+                            return Err(CreationError::OpenGlVersionNotSupported);
                         }
                     }
                     (Some(version), Api::OpenGlEs)
                 },
                 GlRequest::Specific(Api::OpenGl, version) => {
                     if egl_version < (1, 4) {
-                        return Err(CreationError::NotSupported);
+                        return Err(CreationError::OpenGlVersionNotSupported);
                     }
                     if egl.BindAPI(ffi::egl::OPENGL_API) == 0 {
-                        return Err(CreationError::NotSupported);
+                        return Err(CreationError::OpenGlVersionNotSupported);
                     }
                     (Some(version), Api::OpenGl)
                 },
-                GlRequest::Specific(_, _) => return Err(CreationError::NotSupported),
+                GlRequest::Specific(_, _) => return Err(CreationError::OpenGlVersionNotSupported),
                 GlRequest::GlThenGles { opengles_version, opengl_version } => {
                     if egl_version >= (1, 4) {
                         if egl.BindAPI(ffi::egl::OPENGL_API) != 0 {
@@ -99,7 +99,7 @@ impl Context {
                         } else if egl.BindAPI(ffi::egl::OPENGL_ES_API) != 0 {
                             (Some(opengles_version), Api::OpenGlEs)
                         } else {
-                            return Err(CreationError::NotSupported);
+                            return Err(CreationError::OpenGlVersionNotSupported);
                         }
                     } else {
                         (Some(opengles_version), Api::OpenGlEs)
@@ -245,7 +245,7 @@ impl<'a> ContextPrototype<'a> {
                 {
                     ctxt
                 } else {
-                    return Err(CreationError::NotSupported);
+                    return Err(CreationError::OpenGlVersionNotSupported);
                 }
 
             } else {
@@ -267,7 +267,7 @@ impl<'a> ContextPrototype<'a> {
                 {
                     ctxt
                 } else {
-                    return Err(CreationError::NotSupported);
+                    return Err(CreationError::OpenGlVersionNotSupported);
                 }
             }
         };
@@ -434,7 +434,7 @@ unsafe fn create_context(egl: &ffi::egl::Egl, display: ffi::egl::types::EGLDispl
                     context_attributes.push(ffi::egl::NO_RESET_NOTIFICATION as libc::c_int);
                     flags = flags | ffi::egl::CONTEXT_OPENGL_ROBUST_ACCESS as libc::c_int;
                 } else {
-                    return Err(CreationError::NotSupported);
+                    return Err(CreationError::RobustnessNotSupported);
                 }
             },
 
@@ -454,7 +454,7 @@ unsafe fn create_context(egl: &ffi::egl::Egl, display: ffi::egl::types::EGLDispl
                     context_attributes.push(ffi::egl::LOSE_CONTEXT_ON_RESET as libc::c_int);
                     flags = flags | ffi::egl::CONTEXT_OPENGL_ROBUST_ACCESS as libc::c_int;
                 } else {
-                    return Err(CreationError::NotSupported);
+                    return Err(CreationError::RobustnessNotSupported);
                 }
             },
 
@@ -488,7 +488,7 @@ unsafe fn create_context(egl: &ffi::egl::Egl, display: ffi::egl::types::EGLDispl
         // robustness is not supported
         match gl_robustness {
             Robustness::RobustNoResetNotification | Robustness::RobustLoseContextOnReset => {
-                return Err(CreationError::NotSupported);
+                return Err(CreationError::RobustnessNotSupported);
             },
             _ => ()
         }
@@ -504,7 +504,7 @@ unsafe fn create_context(egl: &ffi::egl::Egl, display: ffi::egl::types::EGLDispl
 
     if context.is_null() {
         match egl.GetError() as u32 {
-            ffi::egl::BAD_ATTRIBUTE => return Err(CreationError::NotSupported),
+            ffi::egl::BAD_ATTRIBUTE => return Err(CreationError::OpenGlVersionNotSupported),
             e => panic!("eglCreateContext failed: 0x{:x}", e),
         }
     }
diff --git a/src/api/glx/mod.rs b/src/api/glx/mod.rs
index e0adde7..65819f8 100644
--- a/src/api/glx/mod.rs
+++ b/src/api/glx/mod.rs
@@ -301,7 +301,7 @@ fn create_context(glx: &ffi::glx::Glx, extra_functions: &ffi::glx_extra::Glx, ex
                 } else {
                     match robustness {
                         Robustness::RobustNoResetNotification | Robustness::RobustLoseContextOnReset => {
-                            return Err(CreationError::NotSupported);
+                            return Err(CreationError::RobustnessNotSupported);
                         },
                         _ => ()
                     }
@@ -328,6 +328,7 @@ fn create_context(glx: &ffi::glx::Glx, extra_functions: &ffi::glx_extra::Glx, ex
         };
 
         if context.is_null() {
+            // TODO: check for errors and return `OpenGlVersionNotSupported`
             return Err(CreationError::OsError(format!("GL context creation failed")));
         }
 
diff --git a/src/api/osmesa/mod.rs b/src/api/osmesa/mod.rs
index db0a1e7..056e2d1 100644
--- a/src/api/osmesa/mod.rs
+++ b/src/api/osmesa/mod.rs
@@ -41,11 +41,13 @@ impl OsMesaContext {
 
         match builder.gl_robustness {
             Robustness::RobustNoResetNotification | Robustness::RobustLoseContextOnReset => {
-                return Err(CreationError::NotSupported.into());
+                return Err(CreationError::RobustnessNotSupported.into());
             },
             _ => ()
         }
 
+        // TODO: check OpenGL version and return `OpenGlVersionNotSupported` if necessary
+
         Ok(OsMesaContext {
             width: dimensions.0,
             height: dimensions.1,
diff --git a/src/api/wgl/mod.rs b/src/api/wgl/mod.rs
index 222620c..89538f1 100644
--- a/src/api/wgl/mod.rs
+++ b/src/api/wgl/mod.rs
@@ -235,7 +235,7 @@ unsafe fn create_context(extra: Option<(&gl::wgl_extra::Wgl, &BuilderAttribs<'st
                         attributes.push(gl::wgl_extra::CONTEXT_PROFILE_MASK_ARB as libc::c_int);
                         attributes.push(gl::wgl_extra::CONTEXT_ES2_PROFILE_BIT_EXT as libc::c_int);
                     } else {
-                        return Err(CreationError::NotSupported);
+                        return Err(CreationError::OpenGlVersionNotSupported);
                     }
 
                     attributes.push(gl::wgl_extra::CONTEXT_MAJOR_VERSION_ARB as libc::c_int);
@@ -243,7 +243,7 @@ unsafe fn create_context(extra: Option<(&gl::wgl_extra::Wgl, &BuilderAttribs<'st
                     attributes.push(gl::wgl_extra::CONTEXT_MINOR_VERSION_ARB as libc::c_int);
                     attributes.push(minor as libc::c_int);
                 },
-                GlRequest::Specific(_, _) => return Err(CreationError::NotSupported),
+                GlRequest::Specific(_, _) => return Err(CreationError::OpenGlVersionNotSupported),
                 GlRequest::GlThenGles { opengl_version: (major, minor), .. } => {
                     attributes.push(gl::wgl_extra::CONTEXT_MAJOR_VERSION_ARB as libc::c_int);
                     attributes.push(major as libc::c_int);
@@ -290,7 +290,7 @@ unsafe fn create_context(extra: Option<(&gl::wgl_extra::Wgl, &BuilderAttribs<'st
                 } else {
                     match builder.gl_robustness {
                         Robustness::RobustNoResetNotification | Robustness::RobustLoseContextOnReset => {
-                            return Err(CreationError::NotSupported);
+                            return Err(CreationError::RobustnessNotSupported);
                         },
                         _ => ()
                     }
@@ -573,5 +573,5 @@ fn choose_dummy_pixel_format<I>(iter: I) -> Result<libc::c_int, CreationError>
         }
     }
 
-    backup_id.ok_or(CreationError::NotSupported)
+    backup_id.ok_or(CreationError::OsError("No available pixel format".to_string()))
 }
diff --git a/src/lib.rs b/src/lib.rs
index d43dcfb..9821c9f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -108,7 +108,11 @@ pub trait GlContext {
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum CreationError {
     OsError(String),
+    /// TODO: remove this error
     NotSupported,
+    RobustnessNotSupported,
+    OpenGlVersionNotSupported,
+    NoAvailablePixelFormat,
 }
 
 impl CreationError {
@@ -116,6 +120,12 @@ impl CreationError {
         match *self {
             CreationError::OsError(ref text) => &text,
             CreationError::NotSupported => "Some of the requested attributes are not supported",
+            CreationError::RobustnessNotSupported => "Your requested robustness, but it is \
+                                                      not supported.",
+            CreationError::OpenGlVersionNotSupported => "The requested OpenGL version is not \
+                                                         supported.",
+            CreationError::NoAvailablePixelFormat => "Couldn't find any pixel format that matches \
+                                                      the criterias.",
         }
     }
 }
@@ -465,7 +475,7 @@ impl<'a> BuilderAttribs<'a> {
         }
 
         current_result.or(current_software_result)
-                      .ok_or(CreationError::NotSupported)
+                      .ok_or(CreationError::NoAvailablePixelFormat)
     }
 }