diff --git a/citro3d-sys/src/base.rs b/citro3d-sys/src/base.rs
index 7ca1ada..16463dc 100644
--- a/citro3d-sys/src/base.rs
+++ b/citro3d-sys/src/base.rs
@@ -1,9 +1,9 @@
-//! `<c3d/base.h>`
+//! Definitions from `<c3d/base.h>`
 
-use super::*;
-use libc::c_int;
+use crate::C3D_FixedAttribGetWritePtr;
 
-pub unsafe fn C3D_FixedAttribSet(id: c_int, x: f32, y: f32, z: f32, w: f32) {
+#[inline]
+pub unsafe fn C3D_FixedAttribSet(id: libc::c_int, x: f32, y: f32, z: f32, w: f32) {
     let ptr = C3D_FixedAttribGetWritePtr(id);
     (*ptr).c.copy_from_slice(&[x, y, z, w]);
 }
diff --git a/citro3d-sys/src/gx.rs b/citro3d-sys/src/gx.rs
new file mode 100644
index 0000000..9be28ed
--- /dev/null
+++ b/citro3d-sys/src/gx.rs
@@ -0,0 +1,33 @@
+//! Helper functions based on `<3ds/gpu/gx.h>`.
+
+use crate::{GX_TRANSFER_FORMAT, GX_TRANSFER_SCALE};
+
+#[inline]
+pub fn GX_TRANSFER_FLIP_VERT(flip: bool) -> u32 {
+    flip as u32
+}
+
+#[inline]
+pub fn GX_TRANSFER_OUT_TILED(tiled: bool) -> u32 {
+    (tiled as u32) << 1
+}
+
+#[inline]
+pub fn GX_TRANSFER_RAW_COPY(raw_copy: bool) -> u32 {
+    (raw_copy as u32) << 3
+}
+
+#[inline]
+pub fn GX_TRANSFER_IN_FORMAT(format: GX_TRANSFER_FORMAT) -> u32 {
+    format << 8
+}
+
+#[inline]
+pub fn GX_TRANSFER_OUT_FORMAT(format: GX_TRANSFER_FORMAT) -> u32 {
+    format << 12
+}
+
+#[inline]
+pub fn GX_TRANSFER_SCALING(scale: GX_TRANSFER_SCALE) -> u32 {
+    scale << 24
+}
diff --git a/citro3d-sys/src/lib.rs b/citro3d-sys/src/lib.rs
index 8e17aae..3426e83 100644
--- a/citro3d-sys/src/lib.rs
+++ b/citro3d-sys/src/lib.rs
@@ -6,6 +6,7 @@
 #![allow(clippy::all)]
 
 pub mod base;
+pub mod gx;
 pub mod renderqueue;
 pub mod texenv;
 pub mod uniforms;
@@ -14,6 +15,7 @@ mod bindings;
 
 pub use base::*;
 pub use bindings::*;
+pub use gx::*;
 pub use renderqueue::*;
 pub use texenv::*;
 pub use uniforms::*;
diff --git a/citro3d-sys/src/renderqueue.rs b/citro3d-sys/src/renderqueue.rs
index 3385cfa..cb7050f 100644
--- a/citro3d-sys/src/renderqueue.rs
+++ b/citro3d-sys/src/renderqueue.rs
@@ -1,5 +1,6 @@
-//! `<c3d/renderqueue.h>`
+//! Definitions from `<c3d/renderqueue.h>`
 
+#[inline]
 pub unsafe fn C3D_RenderTargetClear(
     target: *mut crate::C3D_RenderTarget,
     clearBits: crate::C3D_ClearBits,
diff --git a/citro3d-sys/src/texenv.rs b/citro3d-sys/src/texenv.rs
index f7ef661..f52ffac 100644
--- a/citro3d-sys/src/texenv.rs
+++ b/citro3d-sys/src/texenv.rs
@@ -1,9 +1,8 @@
-//! Definitions for `<c3d/texenv.h>`.
+//! Definitions from `<c3d/texenv.h>`.
+//!
 //! Most of these functions are `static inline` so they don't get generated by `bindgen`.
 //! See <https://github.com/rust-lang/rust-bindgen/issues/1090>.
 
-// TODO: probably should mark these all as #[inline] for parity with the C code
-
 use core::ops::{BitOr, Shl};
 
 use libc::c_int;
@@ -13,6 +12,7 @@ use super::*;
 // TODO: why are these two different macros in C?
 
 /// Creates a texture combiner source parameter from three sources.
+#[inline]
 fn GPU_TEVSOURCES<T>(a: T, b: T, c: T) -> T
 where
     T: BitOr<Output = T> + Shl<u8, Output = T>,
@@ -21,6 +21,7 @@ where
 }
 
 /// Creates a texture combiner operand parameter from three operands.
+#[inline]
 fn GPU_TEVOPERANDS<T>(a: T, b: T, c: T) -> T
 where
     T: BitOr<Output = T> + Shl<u8, Output = T>,
@@ -28,6 +29,7 @@ where
     a | b << 4 | c << 8
 }
 
+#[inline]
 pub unsafe fn C3D_TexEnvInit(env: *mut C3D_TexEnv) {
     (*env).srcRgb = GPU_TEVSOURCES(GPU_PREVIOUS, 0, 0) as u16;
     (*env).srcAlpha = (*env).srcRgb;
@@ -39,6 +41,7 @@ pub unsafe fn C3D_TexEnvInit(env: *mut C3D_TexEnv) {
     (*env).scaleAlpha = GPU_TEVSCALE_1 as u16;
 }
 
+#[inline]
 pub unsafe fn C3D_TexEnvSrc(
     env: *mut C3D_TexEnv,
     mode: C3D_TexEnvMode,
@@ -58,6 +61,7 @@ pub unsafe fn C3D_TexEnvSrc(
 }
 
 // TODO: match API of texenv.h
+#[inline]
 pub unsafe fn C3D_TexEnvOp(
     env: *mut C3D_TexEnv,
     mode: C3D_TexEnvMode,
@@ -83,6 +87,7 @@ pub unsafe fn C3D_TexEnvOp(
     }
 }
 
+#[inline]
 pub unsafe fn C3D_TexEnvFunc(env: *mut C3D_TexEnv, mode: C3D_TexEnvMode, param: GPU_COMBINEFUNC) {
     if mode & C3D_RGB != 0 {
         (*env).funcRgb = param as u16;
diff --git a/citro3d-sys/src/uniforms.rs b/citro3d-sys/src/uniforms.rs
index c2b0290..b2df616 100644
--- a/citro3d-sys/src/uniforms.rs
+++ b/citro3d-sys/src/uniforms.rs
@@ -1,11 +1,13 @@
-//! `<c3d/uniforms.h>`
+//! Definitions from`<c3d/uniforms.h>`
 
-use super::*;
-
-use libc::c_int;
+use super::{C3D_FVUnif, C3D_FVUnifDirty, C3D_FVec, C3D_Mtx, GPU_SHADER_TYPE};
 
 #[inline]
-pub unsafe fn C3D_FVUnifWritePtr(type_: GPU_SHADER_TYPE, id: c_int, size: c_int) -> *mut C3D_FVec {
+pub unsafe fn C3D_FVUnifWritePtr(
+    type_: GPU_SHADER_TYPE,
+    id: libc::c_int,
+    size: libc::c_int,
+) -> *mut C3D_FVec {
     for i in 0..size {
         C3D_FVUnifDirty[type_ as usize][(id + i) as usize] = true;
     }
@@ -14,7 +16,12 @@ pub unsafe fn C3D_FVUnifWritePtr(type_: GPU_SHADER_TYPE, id: c_int, size: c_int)
 }
 
 #[inline]
-pub unsafe fn C3D_FVUnifMtxNx4(type_: GPU_SHADER_TYPE, id: c_int, mtx: *const C3D_Mtx, num: c_int) {
+pub unsafe fn C3D_FVUnifMtxNx4(
+    type_: GPU_SHADER_TYPE,
+    id: libc::c_int,
+    mtx: *const C3D_Mtx,
+    num: libc::c_int,
+) {
     let ptr = C3D_FVUnifWritePtr(type_, id, num);
 
     for i in 0..num {
@@ -23,12 +30,19 @@ pub unsafe fn C3D_FVUnifMtxNx4(type_: GPU_SHADER_TYPE, id: c_int, mtx: *const C3
 }
 
 #[inline]
-pub unsafe fn C3D_FVUnifMtx4x4(type_: GPU_SHADER_TYPE, id: c_int, mtx: *const C3D_Mtx) {
+pub unsafe fn C3D_FVUnifMtx4x4(type_: GPU_SHADER_TYPE, id: libc::c_int, mtx: *const C3D_Mtx) {
     C3D_FVUnifMtxNx4(type_, id, mtx, 4);
 }
 
 #[inline]
-pub unsafe fn C3D_FVUnifSet(type_: GPU_SHADER_TYPE, id: c_int, x: f32, y: f32, z: f32, w: f32) {
+pub unsafe fn C3D_FVUnifSet(
+    type_: GPU_SHADER_TYPE,
+    id: libc::c_int,
+    x: f32,
+    y: f32,
+    z: f32,
+    w: f32,
+) {
     let ptr = C3D_FVUnifWritePtr(type_, id, 1);
     (*ptr).c.copy_from_slice(&[x, y, z, w]);
 }