Expand gfx into a droppable type.

On creation, Gfx will init gfx. On drop, it will exit. You should
wrap it in an Rc to move it around.

src/gfx.rs

@@ -1,31 +1,105 @@
 use ::raw::gfx;
 
-pub fn init_default() -> () {
-    unsafe {
-        gfx::gfxInitDefault();
+use core::default::Default;
+use core::marker::PhantomData;
+use core::ops::Drop;
+
+use ::services::gsp::FramebufferFormat;
+
+pub struct Gfx {
+    // we do this to prevent people from making a Gfx struct manually
+    pd: PhantomData<i32>
+}
+
+#[derive(Copy, Clone)]
+pub enum Screen {
+    Top,
+    Bottom
+}
+
+#[derive(Copy, Clone)]
+pub enum Side {
+    Left,
+    Right
+}
+
+#[inline] fn screen_to_raw(s: Screen) -> gfx::gfxScreen_t {
+    match s {
+        Screen::Top => gfx::gfxScreen_t::GFX_TOP,
+        Screen::Bottom => gfx::gfxScreen_t::GFX_BOTTOM
     }
 }
 
-pub fn exit() -> () {
-    unsafe {
-        gfx::gfxExit();
+#[inline] fn side3d_to_raw(s: Side) -> gfx::gfx3dSide_t {
+    match s {
+        Side::Left => gfx::gfx3dSide_t::GFX_LEFT,
+        Side::Right => gfx::gfx3dSide_t::GFX_RIGHT
     }
 }
 
-pub fn set_3d_enabled(enabled: bool) -> () {
-    unsafe {
-        gfx::gfxSet3D(match enabled { true => 1u8, false => 0u8 });
+impl Gfx {
+    pub fn set_3d_enabled(&mut self, enabled: bool) {
+        unsafe {
+            gfx::gfxSet3D(match enabled { true => 1u8, false => 0u8 });
+        }
+    }
+
+    pub fn get_framebuffer(& mut self, screen: Screen, side: Side) -> (&'static mut [u8], u16, u16) {
+        unsafe {
+            use core::slice::from_raw_parts_mut;
+
+            let mut w: u16 = 0;
+            let mut h: u16 = 0;
+            let buf: *mut u8 = gfx::gfxGetFramebuffer(screen_to_raw(screen), side3d_to_raw(side), &mut w as *mut u16, &mut h as &mut u16);
+
+            let fbfmt = self.get_framebuffer_format(screen);
+
+            (from_raw_parts_mut(buf, (w as usize * h as usize) * fbfmt.pixel_depth_bytes()), w, h)
+        }
+    }
+
+    pub fn flush_buffers(&mut self) {
+        unsafe { gfx::gfxFlushBuffers() };
+    }
+
+    pub fn swap_buffers(&mut self) {
+        unsafe { gfx::gfxSwapBuffers() };
+    }
+
+    pub fn swap_buffers_gpu(&mut self) {
+        unsafe { gfx::gfxSwapBuffersGpu() };
+    }
+
+    pub fn get_framebuffer_format(&self, screen: Screen) -> FramebufferFormat {
+        use core::convert::Into;
+        unsafe {
+            gfx::gfxGetScreenFormat(screen_to_raw(screen)).into()
+        }
+    }
+
+    pub fn set_framebuffer_format(&mut self, screen: Screen, fmt: FramebufferFormat) {
+        use core::convert::Into;
+        unsafe {
+            gfx::gfxSetScreenFormat(screen_to_raw(screen), fmt.into())
+        }
+    }
+
+    pub fn set_double_buffering(&mut self, screen: Screen, enabled: bool) {
+        unsafe {
+            gfx::gfxSetDoubleBuffering(screen_to_raw(screen), match enabled { true => 1u8, false => 0u8 })
+        };
     }
 }
 
-pub fn flush_buffers() -> () {
-    unsafe {
-        gfx::gfxFlushBuffers();
+impl Default for Gfx {
+    fn default() -> Self {
+        unsafe { gfx::gfxInitDefault() };
+        Gfx { pd: PhantomData }
     }
 }
 
-pub fn swap_buffers() -> () {
-    unsafe {
-        gfx::gfxSwapBuffers();
+impl Drop for Gfx {
+    fn drop(&mut self) {
+        unsafe { gfx::gfxExit() };
     }
 }

src/raw/services/gsp.rs

@@ -18,6 +18,7 @@ pub struct GSP_FramebufferInfo {
 }
 
 #[repr(C)]
+#[derive(Clone, Copy)]
 pub enum GSP_FramebufferFormats {
 	GSP_RGBA8_OES=0, //pixel_size = 4-bytes
 	GSP_BGR8_OES=1, //pixel_size = 3-bytes

src/services/apt.rs

@@ -1,7 +1,5 @@
 use ::Result;
 
-use core::ops::Fn;
-
 use ::raw::services::apt;
 
 pub enum AppStatus {
@@ -102,7 +100,7 @@ pub fn return_to_menu() -> () {
 ///     false
 /// });
 /// ```
-pub fn main_loop<F>(f: F) -> () where F : Fn() -> bool {
+pub fn main_loop<F>(mut f: F) -> () where F : FnMut() -> bool {
     unsafe {
         while apt::aptMainLoop() != 0 {
             if !f() { break; }

src/services/gsp.rs

@@ -1,5 +1,7 @@
 use ::raw::services::gsp;
 
+use core::convert::From;
+
 pub enum Event {
     Psc0,
     Psc1,
@@ -10,6 +12,56 @@ pub enum Event {
     DMA
 }
 
+#[derive(Copy, Clone)]
+pub enum FramebufferFormat {
+    Rgba8,
+    Bgr8,
+    Rgb565,
+    Rgb5A1,
+    Rgba4
+}
+
+impl FramebufferFormat {
+    pub fn pixel_depth_bytes(&self) -> usize {
+        use self::FramebufferFormat::*;
+        match *self {
+            Rgba8 => 4usize,
+            Bgr8 => 3usize,
+            Rgb565 => 2usize,
+            Rgb5A1 => 2usize,
+            Rgba4 => 2usize
+        }
+    }
+}
+
+impl From<gsp::GSP_FramebufferFormats> for FramebufferFormat {
+    #[inline] fn from(g: gsp::GSP_FramebufferFormats) -> FramebufferFormat {
+        use ::raw::services::gsp::GSP_FramebufferFormats::*;
+        use self::FramebufferFormat::*;
+        match g {
+            GSP_RGBA8_OES => Rgba8,
+            GSP_BGR8_OES => Bgr8,
+            GSP_RGB565_OES => Rgb565,
+            GSP_RGB5_A1_OES => Rgb5A1,
+            GSP_RGBA4_OES => Rgba4
+        }
+    }
+}
+
+impl From<FramebufferFormat> for gsp::GSP_FramebufferFormats {
+    #[inline] fn from(g: FramebufferFormat) -> gsp::GSP_FramebufferFormats {
+        use ::raw::services::gsp::GSP_FramebufferFormats::*;
+        use self::FramebufferFormat::*;
+        match g {
+            Rgba8 => GSP_RGBA8_OES,
+            Bgr8 => GSP_BGR8_OES,
+            Rgb565 => GSP_RGB565_OES,
+            Rgb5A1 => GSP_RGB5_A1_OES,
+            Rgba4 => GSP_RGBA4_OES
+        }
+    }
+}
+
 fn to_raw_event(ev: Event) -> gsp::GSP_Event {
     use ::raw::services::gsp::GSP_Event::*;
     use self::Event::*;