diff --git a/include/c3d/texenv.h b/include/c3d/texenv.h
index 9a42d1b..c14b36d 100644
--- a/include/c3d/texenv.h
+++ b/include/c3d/texenv.h
@@ -1,6 +1,13 @@
+/**
+ * @file texenv.h
+ * @brief Configure texture combiner stages (TexEnv)
+ * @see https://www.khronos.org/opengl/wiki/Texture_Combiners
+ * @see https://www.khronos.org/registry/OpenGL-Refpages/gl2.1/xhtml/glTexEnv.xml
+ */
 #pragma once
 #include "types.h"
 
+/// TexEnv stage configuration
 typedef struct
 {
 	u16 srcRgb, srcAlpha;
@@ -14,20 +21,52 @@ typedef struct
 	u16 scaleRgb, scaleAlpha;
 } C3D_TexEnv;
 
+/// TexEnv operation mode
 typedef enum
 {
-	C3D_RGB = BIT(0),
-	C3D_Alpha = BIT(1),
-	C3D_Both = C3D_RGB | C3D_Alpha,
+	C3D_RGB = BIT(0),               ///< RGB mode
+	C3D_Alpha = BIT(1),             ///< Alpha mode
+	C3D_Both = C3D_RGB | C3D_Alpha, ///< Both
 } C3D_TexEnvMode;
 
+/**
+ * @brief Gets the global TexEnv for a given stage.
+ * @param[in] id TexEnv stage between 0-5 to return.
+ * @return TexEnv of the given stage.
+ */
 C3D_TexEnv* C3D_GetTexEnv(int id);
+
+/**
+ * @brief Sets the global TexEnv for a given stage.
+ * @param[in] id  TexEnv stage between 0-5 to set.
+ * @param[in] env Pointer to user TexEnv.
+ */
 void C3D_SetTexEnv(int id, C3D_TexEnv* env);
+
+/**
+ * @brief Marks a TexEnv as needing to be updated.
+ * @note One must use this if they are continuing to use a TexEnv pointer they got from \ref C3D_GetTexEnv() after performing an action that flushes state.
+ * @param[in] env Pointer to a TexEnv struct.
+ */
 void C3D_DirtyTexEnv(C3D_TexEnv* env);
 
+/**
+ * @brief Configures the stages where the GPU_PREVIOUS_BUFFER source value should be updated with the output of that stage.
+ * @param[in] mode TexEnv update modes (see \ref C3D_TexEnvMode)
+ * @param[in] mask Bitmask containing which stages update GPU_PREVIOUS_BUFFER (bitmask can be created using \ref GPU_TEV_BUFFER_WRITE_CONFIG())
+ */
 void C3D_TexEnvBufUpdate(int mode, int mask);
+
+/**
+ * @brief Configure the initial value of GPU_PREVIOUS_BUFFER. This value will be kept until it is updated; see \ref C3D_TexEnvBufUpdate().
+ * @param[in] color Color value.
+ */
 void C3D_TexEnvBufColor(u32 color);
 
+/**
+ * @brief Resets a TexEnv to its default values.
+ * @param[out] env TexEnv to initialize.
+ */
 static inline void C3D_TexEnvInit(C3D_TexEnv* env)
 {
 	env->srcRgb     = GPU_TEVSOURCES(GPU_PREVIOUS, 0, 0);
@@ -46,6 +85,14 @@ static inline void C3D_TexEnvInit(C3D_TexEnv* env)
 #define _C3D_DEFAULT(x)
 #endif
 
+/**
+ * @brief Sets the input source of a TexEnv.
+ * @param[out] env  Pointer to TexEnv struct.
+ * @param[in]  mode TexEnv update modes (see \ref C3D_TexEnvMode)
+ * @param[in]  s1   First source.
+ * @param[in]  s2   Second source.
+ * @param[in]  s3   Third source.
+ */
 static inline void C3D_TexEnvSrc(C3D_TexEnv* env, C3D_TexEnvMode mode,
 	GPU_TEVSRC s1,
 	GPU_TEVSRC s2 _C3D_DEFAULT(GPU_PRIMARY_COLOR),
@@ -58,6 +105,13 @@ static inline void C3D_TexEnvSrc(C3D_TexEnv* env, C3D_TexEnvMode mode,
 		env->srcAlpha = param;
 }
 
+/**
+ * @brief Configures the operation to be applied to the input color of a TexEnv before the function is applied.
+ * @param[out] env Pointer to TexEnv struct.
+ * @param[in]  o1  Operation to perform on the first source.
+ * @param[in]  o2  Operation to perform on the second source.
+ * @param[in]  o3  Operation to perform on the third source.
+ */
 static inline void C3D_TexEnvOpRgb(C3D_TexEnv* env,
 	GPU_TEVOP_RGB o1,
 	GPU_TEVOP_RGB o2 _C3D_DEFAULT(GPU_TEVOP_RGB_SRC_COLOR),
@@ -66,6 +120,13 @@ static inline void C3D_TexEnvOpRgb(C3D_TexEnv* env,
 	env->opRgb = GPU_TEVOPERANDS((int)o1, (int)o2, (int)o3);
 }
 
+/**
+ * @brief Configures the operation to be applied to the input alpha of a TexEnv before the function is applied.
+ * @param[out] env Pointer to TexEnv struct.
+ * @param[in]  o1  Operation to perform on the first source.
+ * @param[in]  o2  Operation to perform on the second source.
+ * @param[in]  o3  Operation to perform on the third source.
+ */
 static inline void C3D_TexEnvOpAlpha(C3D_TexEnv* env,
 	GPU_TEVOP_A o1,
 	GPU_TEVOP_A o2 _C3D_DEFAULT(GPU_TEVOP_A_SRC_ALPHA),
@@ -74,6 +135,12 @@ static inline void C3D_TexEnvOpAlpha(C3D_TexEnv* env,
 	env->opAlpha = GPU_TEVOPERANDS((int)o1, (int)o2, (int)o3);
 }
 
+/**
+ * @brief Sets the combiner function to perform in this TexEnv.
+ * @param[out] env   Pointer to TexEnv struct.
+ * @param[in]  mode  TexEnv update modes (see \ref C3D_TexEnvMode)
+ * @param[in]  param Function to use.
+ */
 static inline void C3D_TexEnvFunc(C3D_TexEnv* env, C3D_TexEnvMode mode, GPU_COMBINEFUNC param)
 {
 	if ((int)mode & C3D_RGB)
@@ -82,11 +149,22 @@ static inline void C3D_TexEnvFunc(C3D_TexEnv* env, C3D_TexEnvMode mode, GPU_COMB
 		env->funcAlpha = param;
 }
 
+/**
+ * @brief Sets the value of the GPU_CONSTANT source for a TexEnv stage.
+ * @param[out] env   Pointer to TexEnv struct.
+ * @param[in]  color RGBA color value to apply.
+ */
 static inline void C3D_TexEnvColor(C3D_TexEnv* env, u32 color)
 {
 	env->color = color;
 }
 
+/**
+ * @brief Configures the scaling to be applied to the output of a TexEnv.
+ * @param[out] env   Pointer to TexEnv struct.
+ * @param[in]  mode  TexEnv update modes (see \ref C3D_TexEnvMode)
+ * @param[in]  param Scale factor to apply.
+ */
 static inline void C3D_TexEnvScale(C3D_TexEnv* env, int mode, GPU_TEVSCALE param)
 {
 	if (mode & C3D_RGB)