feat(engine): add texturing

2 files changed, 145 insertions, 0 deletions

diff --git a/engine/src/opengl/mod.rs b/engine/src/opengl/mod.rs
index 4f4f96f..d58ca50 100644
--- a/engine/src/opengl/mod.rs
+++ b/engine/src/opengl/mod.rs
@@ -6,6 +6,7 @@ use crate::vector::Vec2;
 pub mod buffer;
 pub mod currently_bound;
 pub mod shader;
+pub mod texture;
 pub mod vertex_array;
 
 mod util;
diff --git a/engine/src/opengl/texture.rs b/engine/src/opengl/texture.rs
new file mode 100644
index 0000000..c7bf75b
--- /dev/null
+++ b/engine/src/opengl/texture.rs
@@ -0,0 +1,144 @@
+use crate::opengl::currently_bound::CurrentlyBound;
+use crate::vector::Vec2;
+
+#[derive(Debug)]
+pub struct Texture
+{
+    texture: gl::types::GLuint,
+}
+
+impl Texture
+{
+    pub fn new() -> Self
+    {
+        let mut texture = gl::types::GLuint::default();
+
+        unsafe {
+            gl::GenTextures(1, &mut texture);
+        };
+
+        Self { texture }
+    }
+
+    pub fn bind(&self, cb: impl FnOnce(CurrentlyBound<'_, Self>))
+    {
+        unsafe {
+            gl::BindTexture(gl::TEXTURE_2D, self.texture);
+        }
+
+        // SAFETY: The buffer object is bound above
+        let currently_bound = unsafe { CurrentlyBound::new() };
+
+        cb(currently_bound);
+    }
+
+    pub fn generate(_: &CurrentlyBound<Self>, dimens: &Vec2<u32>, data: &[u8])
+    {
+        #[allow(clippy::cast_possible_wrap)]
+        unsafe {
+            gl::TexImage2D(
+                gl::TEXTURE_2D,
+                0,
+                gl::RGB as i32,
+                dimens.x as i32,
+                dimens.y as i32,
+                0,
+                gl::RGB,
+                gl::UNSIGNED_BYTE,
+                data.as_ptr().cast(),
+            );
+
+            gl::GenerateMipmap(gl::TEXTURE_2D);
+        }
+    }
+
+    pub fn set_wrap(_: CurrentlyBound<Self>, wrapping: Wrapping)
+    {
+        let wrapping_gl = wrapping.to_gl();
+
+        #[allow(clippy::cast_possible_wrap)]
+        unsafe {
+            gl::TexParameteri(gl::TEXTURE_2D, gl::TEXTURE_WRAP_S, wrapping_gl as i32);
+            gl::TexParameteri(gl::TEXTURE_2D, gl::TEXTURE_WRAP_T, wrapping_gl as i32);
+        }
+    }
+
+    pub fn set_magnifying_filter(_: CurrentlyBound<Self>, filtering: Filtering)
+    {
+        let filtering_gl = filtering.to_gl();
+
+        #[allow(clippy::cast_possible_wrap)]
+        unsafe {
+            gl::TexParameteri(
+                gl::TEXTURE_2D,
+                gl::TEXTURE_MAG_FILTER,
+                filtering_gl as i32,
+            );
+        }
+    }
+
+    pub fn set_minifying_filter(_: CurrentlyBound<Self>, filtering: Filtering)
+    {
+        let filtering_gl = filtering.to_gl();
+
+        #[allow(clippy::cast_possible_wrap)]
+        unsafe {
+            gl::TexParameteri(
+                gl::TEXTURE_2D,
+                gl::TEXTURE_MIN_FILTER,
+                filtering_gl as i32,
+            );
+        }
+    }
+}
+
+impl Drop for Texture
+{
+    fn drop(&mut self)
+    {
+        unsafe {
+            gl::DeleteTextures(1, &self.texture);
+        }
+    }
+}
+
+/// Texture wrapping.
+#[derive(Debug, Clone, Copy)]
+pub enum Wrapping
+{
+    Repeat,
+    MirroredRepeat,
+    ClampToEdge,
+    ClampToBorder,
+}
+
+impl Wrapping
+{
+    fn to_gl(self) -> gl::types::GLenum
+    {
+        match self {
+            Self::Repeat => gl::REPEAT,
+            Self::MirroredRepeat => gl::MIRRORED_REPEAT,
+            Self::ClampToEdge => gl::CLAMP_TO_EDGE,
+            Self::ClampToBorder => gl::CLAMP_TO_BORDER,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub enum Filtering
+{
+    Nearest,
+    Linear,
+}
+
+impl Filtering
+{
+    fn to_gl(self) -> gl::types::GLenum
+    {
+        match self {
+            Self::Linear => gl::LINEAR,
+            Self::Nearest => gl::NEAREST,
+        }
+    }
+}