Merge pull request #4 from rust3ds/render-target-screen-lifetime

Add mutable ref to `Screen` in `render::Target`

Cargo.toml

@@ -1,5 +1,5 @@
 [workspace]
 members = ["citro3d-sys", "citro3d", "bindgen-citro3d"]
 
-[patch."https://github.com/ian-h-chamberlain/citro3d-rs.git"]
+[patch."https://github.com/rust3ds/citro3d-rs.git"]
 citro3d-sys = { path = "citro3d-sys" }

citro3d-sys/src/renderqueue.rs

@@ -1,11 +1,18 @@
 //! Definitions from `<c3d/renderqueue.h>`
 
+use crate::*;
+
+#[inline]
+pub unsafe fn C3D_RenderTargetDetachOutput(target: *mut C3D_RenderTarget) {
+    C3D_RenderTargetSetOutput(core::ptr::null_mut(), (*target).screen, (*target).side, 0);
+}
+
 #[inline]
 pub unsafe fn C3D_RenderTargetClear(
-    target: *mut crate::C3D_RenderTarget,
-    clearBits: crate::C3D_ClearBits,
+    target: *mut C3D_RenderTarget,
+    clearBits: C3D_ClearBits,
     clearColor: u32,
     clearDepth: u32,
 ) {
-    crate::C3D_FrameBufClear(&mut (*target).frameBuf, clearBits, clearColor, clearDepth);
+    C3D_FrameBufClear(&mut (*target).frameBuf, clearBits, clearColor, clearDepth);
 }

citro3d/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2021"
 [dependencies]
 bitflags = "1.3.2"
 bytemuck = { version = "1.10.0", features = ["extern_crate_std"] }
-citro3d-sys = { git = "https://github.com/ian-h-chamberlain/citro3d-rs.git" }
+citro3d-sys = { git = "https://github.com/rust3ds/citro3d-rs.git" }
 ctru-rs = { git = "https://github.com/rust3ds/ctru-rs.git" }
 ctru-sys = { git = "https://github.com/rust3ds/ctru-rs.git" }
 libc = "0.2.125"

citro3d/examples/triangle.rs

@@ -1,16 +1,18 @@
+#![feature(allocator_api)]
+
+use citro3d::render::{ClearFlags, Target};
 use citro3d::{include_aligned_bytes, shader};
 use citro3d_sys::C3D_Mtx;
-use ctru::gfx::{Gfx, Side};
+use ctru::gfx::{Gfx, RawFrameBuffer, Screen};
 use ctru::services::apt::Apt;
 use ctru::services::hid::{Hid, KeyPad};
 use ctru::services::soc::Soc;
 
-use citro3d::render::{ClearFlags, ColorFormat, DepthFormat};
-
 use std::ffi::CStr;
 use std::mem::MaybeUninit;
 
 #[repr(C)]
+#[derive(Copy, Clone)]
 struct Vec3 {
     x: f32,
     y: f32,
@@ -24,12 +26,13 @@ impl Vec3 {
 }
 
 #[repr(C)]
+#[derive(Copy, Clone)]
 struct Vertex {
     pos: Vec3,
     color: Vec3,
 }
 
-const VERTICES: &[Vertex] = &[
+static VERTICES: &[Vertex] = &[
     Vertex {
         pos: Vec3::new(0.0, 0.5, 0.5),
         color: Vec3::new(1.0, 0.0, 0.0),
@@ -44,7 +47,7 @@ const VERTICES: &[Vertex] = &[
     },
 ];
 
-const SHADER_BYTES: &[u8] =
+static SHADER_BYTES: &[u8] =
     include_aligned_bytes!(concat!(env!("OUT_DIR"), "/examples/assets/vshader.shbin"));
 
 fn main() {
@@ -58,26 +61,28 @@ fn main() {
     let apt = Apt::init().expect("Couldn't obtain APT controller");
 
     let mut top_screen = gfx.top_screen.borrow_mut();
-    let frame_buffer = top_screen.get_raw_framebuffer(Side::Left);
+    let RawFrameBuffer { width, height, .. } = top_screen.get_raw_framebuffer();
 
     let mut instance = citro3d::Instance::new().expect("failed to initialize Citro3D");
 
-    let mut render_target = instance
-        .render_target_for_screen(
-            &frame_buffer,
-            ColorFormat::RGBA8,
-            DepthFormat::Depth24Stencil8,
-        )
+    let mut top_target = citro3d::render::Target::new(width, height, top_screen, None)
         .expect("failed to create render target");
 
-    render_target.set_output(&*top_screen, Side::Left);
+    let mut bottom_screen = gfx.bottom_screen.borrow_mut();
+    let RawFrameBuffer { width, height, .. } = bottom_screen.get_raw_framebuffer();
+
+    let mut bottom_target = citro3d::render::Target::new(width, height, bottom_screen, None)
+        .expect("failed to create bottom screen render target");
 
     let shader = shader::Library::from_bytes(SHADER_BYTES).unwrap();
     let vertex_shader = shader.get(0).unwrap();
 
     let mut program = shader::Program::new(vertex_shader).unwrap();
 
-    let (uloc_projection, projection, vbo_data) = scene_init(&mut program);
+    let mut vbo_data = Vec::with_capacity_in(VERTICES.len(), ctru::linear::LinearAllocator);
+    vbo_data.extend_from_slice(VERTICES);
+
+    let (uloc_projection, projection) = scene_init(&mut program, &vbo_data);
 
     while apt.main_loop() {
         hid.scan_input();
@@ -86,22 +91,24 @@ fn main() {
             break;
         }
 
+        let mut render_to = |target: &mut Target| {
             instance.render_frame_with(|instance| {
-            let clear_color: u32 = 0x7F_7F_7F_FF;
-            render_target.clear(ClearFlags::ALL, clear_color, 0);
-
                 instance
-                .select_render_target(&render_target)
+                    .select_render_target(target)
                     .expect("failed to set render target");
 
+                let clear_color: u32 = 0x7F_7F_7F_FF;
+                target.clear(ClearFlags::ALL, clear_color, 0);
                 scene_render(uloc_projection.into(), &projection);
             });
-    }
+        };
 
-    scene_exit(vbo_data);
+        render_to(&mut top_target);
+        render_to(&mut bottom_target);
+    }
 }
 
-fn scene_init(program: &mut shader::Program) -> (i8, C3D_Mtx, *mut libc::c_void) {
+fn scene_init(program: &mut shader::Program, vbo_data: &[Vertex]) -> (i8, C3D_Mtx) {
     // Load the vertex shader, create a shader program and bind it
     unsafe {
         citro3d_sys::C3D_BindProgram(program.as_raw());
@@ -136,22 +143,12 @@ fn scene_init(program: &mut shader::Program) -> (i8, C3D_Mtx, *mut libc::c_void)
             projection.assume_init()
         };
 
-        // Create the vertex buffer object
-        let vbo_data: *mut Vertex = ctru_sys::linearAlloc(
-            std::mem::size_of_val(&VERTICES)
-                .try_into()
-                .expect("size fits in u32"),
-        )
-        .cast();
-
-        vbo_data.copy_from(VERTICES.as_ptr(), VERTICES.len());
-
         // Configure buffers
         let buf_info = citro3d_sys::C3D_GetBufInfo();
         citro3d_sys::BufInfo_Init(buf_info);
         citro3d_sys::BufInfo_Add(
             buf_info,
-            vbo_data.cast(),
+            vbo_data.as_ptr().cast(),
             std::mem::size_of::<Vertex>()
                 .try_into()
                 .expect("size of vec3 fits in u32"),
@@ -172,7 +169,7 @@ fn scene_init(program: &mut shader::Program) -> (i8, C3D_Mtx, *mut libc::c_void)
         );
         citro3d_sys::C3D_TexEnvFunc(env, citro3d_sys::C3D_Both, ctru_sys::GPU_REPLACE);
 
-        (uloc_projection, projection, vbo_data.cast())
+        (uloc_projection, projection)
     }
 }
 
@@ -192,9 +189,3 @@ fn scene_render(uloc_projection: i32, projection: &C3D_Mtx) {
         );
     }
 }
-
-fn scene_exit(vbo_data: *mut libc::c_void) {
-    unsafe {
-        ctru_sys::linearFree(vbo_data);
-    }
-}

citro3d/src/lib.rs

@@ -7,11 +7,8 @@ pub mod texture;
 pub mod vbo;
 
 use citro3d_sys::C3D_FrameDrawOn;
-use ctru::gfx::RawFrameBuffer;
 pub use error::{Error, Result};
 
-use render::Target;
-
 /// The single instance for using `citro3d`. This is the base type that an application
 /// should instantiate to use this library.
 #[non_exhaustive]
@@ -41,32 +38,12 @@ impl Instance {
         }
     }
 
-    /// Create a default render target for the given screen.
-    ///
-    /// # Errors
-    ///
-    /// Fails if the render target could not be created.
-    pub fn render_target_for_screen(
-        &self,
-        frame_buffer: &RawFrameBuffer,
-        color_format: render::ColorFormat,
-        depth_format: render::DepthFormat,
-    ) -> Result<Target> {
-        let _ = self;
-        Target::new(
-            frame_buffer.width.into(),
-            frame_buffer.height.into(),
-            color_format,
-            depth_format,
-        )
-    }
-
     /// Select the given render target for drawing the frame.
     ///
     /// # Errors
     ///
     /// Fails if the given target cannot be used for drawing.
-    pub fn select_render_target(&mut self, target: &render::Target) -> Result<()> {
+    pub fn select_render_target(&mut self, target: &render::Target<'_>) -> Result<()> {
         let _ = self;
         if unsafe { C3D_FrameDrawOn(target.as_raw()) } {
             Ok(())

citro3d/src/render.rs

@@ -1,10 +1,12 @@
 //! This module provides render target types and options for controlling transfer
 //! of data to the GPU, including the format of color and depth data to be rendered.
 
+use std::cell::RefMut;
+
 use citro3d_sys::{
     C3D_RenderTarget, C3D_RenderTargetCreate, C3D_RenderTargetDelete, C3D_DEPTHTYPE,
 };
-use ctru::gfx;
+use ctru::gfx::Screen;
 use ctru::services::gspgpu::FramebufferFormat;
 use ctru_sys::{GPU_COLORBUF, GPU_DEPTHBUF};
 
@@ -14,12 +16,14 @@ mod transfer;
 
 /// A render target for `citro3d`. Frame data will be written to this target
 /// to be rendered on the GPU and displayed on the screen.
-pub struct Target {
+pub struct Target<'screen> {
     raw: *mut citro3d_sys::C3D_RenderTarget,
-    color_format: ColorFormat,
+    // This is unused after construction, but ensures unique access to the
+    // screen this target writes to during rendering
+    _screen: RefMut<'screen, dyn Screen>,
 }
 
-impl Drop for Target {
+impl Drop for Target<'_> {
     fn drop(&mut self) {
         unsafe {
             C3D_RenderTargetDelete(self.raw);
@@ -27,52 +31,52 @@ impl Drop for Target {
     }
 }
 
-impl Target {
+impl<'screen> Target<'screen> {
     /// Create a new render target with the specified size, color format,
     /// and depth format.
     ///
     /// # Errors
     ///
-    /// Fails if the specified sizes are invalid, or the target could not be
-    /// created.
+    /// Fails if the target could not be created.
     pub fn new(
-        width: u32,
-        height: u32,
-        color_format: ColorFormat,
-        depth_format: DepthFormat,
+        width: u16,
+        height: u16,
+        screen: RefMut<'screen, dyn Screen>,
+        depth_format: Option<DepthFormat>,
     ) -> Result<Self> {
+        let color_format: ColorFormat = screen.get_framebuffer_format().into();
+
         let raw = unsafe {
             C3D_RenderTargetCreate(
-                width.try_into()?,
-                height.try_into()?,
+                width.into(),
+                height.into(),
                 color_format as GPU_COLORBUF,
-                depth_format.as_raw(),
+                depth_format.map_or(C3D_DEPTHTYPE { __i: -1 }, DepthFormat::as_raw),
             )
         };
 
         if raw.is_null() {
-            Err(Error::FailedToInitialize)
-        } else {
-            Ok(Self { raw, color_format })
-        }
+            return Err(Error::FailedToInitialize);
         }
 
-    /// Sets the screen to actually display the output of this render target.
-    pub fn set_output(&mut self, screen: &impl gfx::Screen, side: gfx::Side) {
-        let framebuf_format = screen.get_framebuffer_format();
-
+        // Set the render target to actually output to the given screen
         let flags = transfer::Flags::default()
-            .in_format(self.color_format.into())
-            .out_format(ColorFormat::from(framebuf_format).into());
+            .in_format(color_format.into())
+            .out_format(color_format.into());
 
         unsafe {
             citro3d_sys::C3D_RenderTargetSetOutput(
-                self.raw,
+                raw,
                 screen.as_raw(),
-                side.into(),
+                screen.side().into(),
                 flags.bits(),
             );
         }
+
+        Ok(Self {
+            raw,
+            _screen: screen,
+        })
     }
 
     /// Clear the render target with the given 32-bit RGBA color and depth buffer value.