Start porting <c3d/maths.h>, vectors and matrices

citro3d/examples/triangle.rs

@@ -3,13 +3,10 @@
 
 #![feature(allocator_api)]
 
-use std::ffi::CStr;
-use std::mem::MaybeUninit;
-
 use citro3d::macros::include_shader;
+use citro3d::math::{CoordinateSystem, Matrix};
 use citro3d::render::{self, ClearFlags};
-use citro3d::{attrib, buffer, shader};
-use citro3d_sys::C3D_Mtx;
+use citro3d::{attrib, buffer, shader, AspectRatio};
 use ctru::prelude::*;
 use ctru::services::gfx::{RawFrameBuffer, Screen, TopScreen3D};
 
@@ -92,7 +89,10 @@ fn main() {
     let mut buf_info = buffer::Info::new();
     let (attr_info, vbo_idx) = prepare_vbos(&mut buf_info, &vbo_data);
 
-    let projection_uniform_idx = scene_init(&mut program);
+    scene_init(&mut program);
+
+    let projection_uniform_idx = program.get_uniform_location("projection").unwrap();
+
     while apt.main_loop() {
         hid.scan_input();
 
@@ -109,14 +109,7 @@ fn main() {
                 let clear_color: u32 = 0x7F_7F_7F_FF;
                 target.clear(ClearFlags::ALL, clear_color, 0);
 
-                unsafe {
-                    // Update the uniforms
-                    citro3d_sys::C3D_FVUnifMtx4x4(
-                        ctru_sys::GPU_VERTEX_SHADER,
-                        projection_uniform_idx.into(),
-                        projection,
-                    );
-                }
+                instance.update_vertex_uniform_mat4x4(projection_uniform_idx, projection);
 
                 instance.set_attr_info(&attr_info);
 
@@ -165,16 +158,12 @@ where
 }
 
 struct Projections {
-    left: C3D_Mtx,
-    right: C3D_Mtx,
-    center: C3D_Mtx,
+    left: Matrix,
+    right: Matrix,
+    center: Matrix,
 }
 
 fn calculate_projections() -> Projections {
-    let mut left_eye = MaybeUninit::uninit();
-    let mut right_eye = MaybeUninit::uninit();
-    let mut center = MaybeUninit::uninit();
-
     // TODO: it would be cool to allow playing around with these parameters on
     // the fly with D-pad, etc.
     let slider_val = unsafe { ctru_sys::osGet3DSliderState() };
@@ -182,53 +171,48 @@ fn calculate_projections() -> Projections {
 
     let near = 0.01;
     let far = 100.0;
-    let fovy = 40.0_f32.to_radians();
+    let fov_y = 40.0_f32.to_radians();
     let screen = 2.0;
 
-    unsafe {
-        citro3d_sys::Mtx_PerspStereoTilt(
-            left_eye.as_mut_ptr(),
-            fovy,
-            citro3d_sys::C3D_AspectRatioTop as f32,
+    let left_eye = Matrix::perspective_stereo_tilt(
+        fov_y,
+        AspectRatio::TopScreen,
         near,
         far,
         -iod,
         screen,
-            true,
+        CoordinateSystem::LeftHanded,
     );
 
-        citro3d_sys::Mtx_PerspStereoTilt(
-            right_eye.as_mut_ptr(),
-            fovy,
-            citro3d_sys::C3D_AspectRatioTop as f32,
+    let right_eye = Matrix::perspective_stereo_tilt(
+        fov_y,
+        AspectRatio::TopScreen,
         near,
         far,
         iod,
         screen,
-            true,
+        CoordinateSystem::LeftHanded,
     );
 
-        citro3d_sys::Mtx_PerspTilt(
-            center.as_mut_ptr(),
-            fovy,
-            citro3d_sys::C3D_AspectRatioBot as f32,
+    let center = Matrix::perspective_tilt(
+        fov_y,
+        AspectRatio::BottomScreen,
         near,
         far,
-            true,
+        CoordinateSystem::LeftHanded,
     );
 
     Projections {
-            left: left_eye.assume_init(),
-            right: right_eye.assume_init(),
-            center: center.assume_init(),
-        }
+        left: left_eye,
+        right: right_eye,
+        center,
     }
 }
 
-fn scene_init(program: &mut shader::Program) -> i8 {
+fn scene_init(program: &mut shader::Program) {
     // Load the vertex shader, create a shader program and bind it
     unsafe {
-        citro3d_sys::C3D_BindProgram(program.as_raw());
+        citro3d_sys::C3D_BindProgram(program.as_raw_mut());
 
         // Configure the first fragment shading substage to just pass through the vertex color
         // See https://www.opengl.org/sdk/docs/man2/xhtml/glTexEnv.xml for more insight
@@ -242,13 +226,5 @@ fn scene_init(program: &mut shader::Program) -> i8 {
             0,
         );
         citro3d_sys::C3D_TexEnvFunc(env, citro3d_sys::C3D_Both, ctru_sys::GPU_REPLACE);
-
-        // Get the location of the uniforms
-        let projection_name = CStr::from_bytes_with_nul(b"projection\0").unwrap();
-
-        ctru_sys::shaderInstanceGetUniformLocation(
-            (*program.as_raw()).vertexShader,
-            projection_name.as_ptr(),
-        )
     }
 }

citro3d/src/lib.rs

@@ -5,11 +5,12 @@
 pub mod attrib;
 pub mod buffer;
 pub mod error;
+pub mod math;
 pub mod render;
 pub mod shader;
 
-use citro3d_sys::C3D_FrameDrawOn;
 pub use error::{Error, Result};
+pub use math::Matrix;
 
 pub mod macros {
     //! Helper macros for working with shaders.
@@ -53,7 +54,7 @@ impl Instance {
     /// Fails if the given target cannot be used for drawing.
     pub fn select_render_target(&mut self, target: &render::Target<'_>) -> Result<()> {
         let _ = self;
-        if unsafe { C3D_FrameDrawOn(target.as_raw()) } {
+        if unsafe { citro3d_sys::C3D_FrameDrawOn(target.as_raw()) } {
             Ok(())
         } else {
             Err(Error::InvalidRenderTarget)
@@ -121,6 +122,19 @@ impl Instance {
             );
         }
     }
+
+    // TODO: need separate versions for vertex/geometry and different dimensions?
+    // Maybe we could do something nicer with const generics, or something, although
+    // it will probably be tricker
+    pub fn update_vertex_uniform_mat4x4(&mut self, index: i8, matrix: &Matrix) {
+        unsafe {
+            citro3d_sys::C3D_FVUnifMtx4x4(
+                ctru_sys::GPU_VERTEX_SHADER,
+                index.into(),
+                matrix.as_raw(),
+            )
+        }
+    }
 }
 
 impl Drop for Instance {
@@ -130,3 +144,21 @@ impl Drop for Instance {
         }
     }
 }
+
+#[derive(Clone, Copy, Debug)]
+#[non_exhaustive]
+pub enum AspectRatio {
+    TopScreen,
+    BottomScreen,
+    Other(f32),
+}
+
+impl From<AspectRatio> for f32 {
+    fn from(ratio: AspectRatio) -> Self {
+        match ratio {
+            AspectRatio::TopScreen => citro3d_sys::C3D_AspectRatioTop as f32,
+            AspectRatio::BottomScreen => citro3d_sys::C3D_AspectRatioBot as f32,
+            AspectRatio::Other(ratio) => ratio,
+        }
+    }
+}

citro3d/src/math.rs

@@ -0,0 +1,87 @@
+//! Safe wrappers for working with matrix and vector types provided by `citro3d`.
+
+use std::mem::MaybeUninit;
+
+use crate::AspectRatio;
+
+/// A 4-vector of [`u8`]s.
+pub struct IntVec(citro3d_sys::C3D_IVec);
+
+/// A 4-vector of [`f32`]s.
+pub struct FloatVec(citro3d_sys::C3D_FVec);
+
+/// A quaternion, internally represented the same way as [`FVec`].
+pub struct Quaternion(citro3d_sys::C3D_FQuat);
+
+/// A 4x4 row-major matrix of [`f32`]s.
+pub struct Matrix(citro3d_sys::C3D_Mtx);
+
+/// Whether to use left-handed or right-handed coordinates for calculations.
+#[derive(Clone, Copy, Debug)]
+#[non_exhaustive] // This probably is exhaustive, but just in case
+pub enum CoordinateSystem {
+    LeftHanded,
+    RightHanded,
+}
+
+impl Matrix {
+    // TODO: this could probably be generalized with something like builder or options
+    // pattern. Should look and see what the different citro3d implementations look like
+    pub fn perspective_stereo_tilt(
+        fov_y: f32,
+        aspect_ratio: AspectRatio,
+        near: f32,
+        far: f32,
+        interocular_distance: f32,
+        /* better name ?? */ screen_depth: f32,
+        coordinates: CoordinateSystem,
+    ) -> Self {
+        let mut result = MaybeUninit::uninit();
+
+        let inner = unsafe {
+            citro3d_sys::Mtx_PerspStereoTilt(
+                result.as_mut_ptr(),
+                fov_y,
+                aspect_ratio.into(),
+                near,
+                far,
+                interocular_distance,
+                screen_depth,
+                matches!(coordinates, CoordinateSystem::LeftHanded),
+            );
+
+            result.assume_init()
+        };
+
+        Self(inner)
+    }
+
+    pub fn perspective_tilt(
+        fov_y: f32,
+        aspect_ratio: AspectRatio,
+        near: f32,
+        far: f32,
+        coordinates: CoordinateSystem,
+    ) -> Self {
+        let mut result = MaybeUninit::uninit();
+
+        let inner = unsafe {
+            citro3d_sys::Mtx_PerspTilt(
+                result.as_mut_ptr(),
+                fov_y,
+                aspect_ratio.into(),
+                near,
+                far,
+                matches!(coordinates, CoordinateSystem::LeftHanded),
+            );
+
+            result.assume_init()
+        };
+
+        Self(inner)
+    }
+
+    pub(crate) fn as_raw(&self) -> *const citro3d_sys::C3D_Mtx {
+        &self.0
+    }
+}

citro3d/src/shader.rs

@@ -5,6 +5,7 @@
 //! documentation for <https://github.com/devkitPro/picasso>.
 
 use std::error::Error;
+use std::ffi::CString;
 use std::mem::MaybeUninit;
 
 /// A PICA200 shader program. It may have one or both of:
@@ -66,8 +67,30 @@ impl Program {
         }
     }
 
+    // TODO: newtype for index?
+    pub fn get_uniform_location(&self, name: &str) -> crate::Result<i8> {
+        let vertex_instance = unsafe { (*self.as_raw()).vertexShader };
+        if vertex_instance.is_null() {
+            return Err(todo!());
+        }
+
+        let name = CString::new(name).map_err(|e| -> crate::Error { todo!() })?;
+
+        let idx =
+            unsafe { ctru_sys::shaderInstanceGetUniformLocation(vertex_instance, name.as_ptr()) };
+
+        if idx < 0 {
+            Err(todo!())
+        } else {
+            Ok(idx)
+        }
+    }
     // TODO: pub(crate)
-    pub fn as_raw(&mut self) -> *mut ctru_sys::shaderProgram_s {
+    pub fn as_raw(&self) -> *const ctru_sys::shaderProgram_s {
+        &self.program
+    }
+
+    pub fn as_raw_mut(&mut self) -> *mut ctru_sys::shaderProgram_s {
         &mut self.program
     }
 }
@@ -75,7 +98,7 @@ impl Program {
 impl Drop for Program {
     fn drop(&mut self) {
         unsafe {
-            let _ = ctru_sys::shaderProgramFree(self.as_raw());
+            let _ = ctru_sys::shaderProgramFree(self.as_raw_mut());
         }
     }
 }