Implement multisampling for x11

4 files changed, 28 insertions, 6 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 7a64e70..0e61649 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -94,6 +94,7 @@ pub struct WindowBuilder<'a> {
     gl_debug: bool,
     vsync: bool,
     visible: bool,
+    multisampling: Option<u16>,
 }
 
 #[cfg(feature = "window")]
@@ -109,6 +110,7 @@ impl<'a> WindowBuilder<'a> {
             gl_debug: cfg!(ndebug),
             vsync: false,
             visible: true,
+            multisampling: None,
         }
     }
 
@@ -173,6 +175,18 @@ impl<'a> WindowBuilder<'a> {
         self
     }
 
+    /// Sets the multisampling level to request.
+    ///
+    /// # Panic
+    ///
+    /// Will panic if `samples` is not a power of two.
+    pub fn with_multisampling(mut self, samples: u16) -> WindowBuilder<'a> {
+        use std::num::UnsignedInt;
+        assert!(samples.is_power_of_two());
+        self.multisampling = Some(samples);
+        self
+    }
+
     /// Builds the window.
     ///
     /// Error should be very rare and only occur in case of permission denied, incompatible system,
diff --git a/src/win32/init.rs b/src/win32/init.rs
index 29b45cb..62c1f54 100644
--- a/src/win32/init.rs
+++ b/src/win32/init.rs
@@ -16,7 +16,8 @@ pub fn new_window(builder_dimensions: Option<(uint, uint)>, builder_title: Strin
                   builder_monitor: Option<super::MonitorID>,
                   builder_gl_version: Option<(uint, uint)>, builder_debug: bool,
                   builder_vsync: bool, builder_hidden: bool,
-                  builder_sharelists: Option<ffi::HGLRC>) -> Result<Window, CreationError>
+                  builder_sharelists: Option<ffi::HGLRC>, builder_multisampling: Option<u16>)
+                  -> Result<Window, CreationError>
 {
     use std::mem;
     use std::os;
diff --git a/src/win32/mod.rs b/src/win32/mod.rs
index ef2e3ea..f08c033 100644
--- a/src/win32/mod.rs
+++ b/src/win32/mod.rs
@@ -26,7 +26,7 @@ impl HeadlessContext {
     pub fn new(builder: HeadlessRendererBuilder) -> Result<HeadlessContext, CreationError> {
         let HeadlessRendererBuilder { dimensions, gl_version, gl_debug } = builder;
         init::new_window(Some(dimensions), "".to_string(), None, gl_version, gl_debug, false, true,
-                         None)
+                         None, None)
                          .map(|w| HeadlessContext(w))
     }
 
@@ -70,9 +70,9 @@ impl Window {
     /// See the docs in the crate root file.
     pub fn new(builder: WindowBuilder) -> Result<Window, CreationError> {
         let WindowBuilder { dimensions, title, monitor, gl_version,
-                            gl_debug, vsync, visible, sharing } = builder;
+                            gl_debug, vsync, visible, sharing, multisampling } = builder;
         init::new_window(dimensions, title, monitor, gl_version, gl_debug, vsync,
-                         !visible, sharing.map(|w| w.window.context))
+                         !visible, sharing.map(|w| w.window.context), multisampling)
     }
 }
 
diff --git a/src/x11/window/mod.rs b/src/x11/window/mod.rs
index 8662fdc..72c7133 100644
--- a/src/x11/window/mod.rs
+++ b/src/x11/window/mod.rs
@@ -58,7 +58,7 @@ impl Window {
 
         // getting the FBConfig
         let fb_config = unsafe {
-            const VISUAL_ATTRIBUTES: [libc::c_int, ..23] = [
+            let mut visual_attributes = vec![
                 ffi::GLX_X_RENDERABLE,  1,
                 ffi::GLX_DRAWABLE_TYPE, ffi::GLX_WINDOW_BIT,
                 ffi::GLX_RENDER_TYPE,   ffi::GLX_RGBA_BIT,
@@ -73,10 +73,17 @@ impl Window {
                 0
             ];
 
+            if let Some(val) = builder.multisampling {
+                visual_attributes.push(ffi::glx::SAMPLE_BUFFERS as libc::c_int);
+                visual_attributes.push(1);
+                visual_attributes.push(ffi::glx::SAMPLES as libc::c_int);
+                visual_attributes.push(val as libc::c_int);
+            }
+
             let mut num_fb: libc::c_int = mem::uninitialized();
 
             let fb = ffi::glx::ChooseFBConfig(display, ffi::XDefaultScreen(display),
-                VISUAL_ATTRIBUTES.as_ptr(), &mut num_fb);
+                visual_attributes.as_ptr(), &mut num_fb);
             if fb.is_null() {
                 return Err(OsError(format!("glx::ChooseFBConfig failed")));
             }