1 files changed, 189 insertions, 0 deletions
diff --git a/opengl-bindings/src/framebuffer.rs b/opengl-bindings/src/framebuffer.rs
new file mode 100644
index 0000000..9511f88
--- /dev/null
+++ b/opengl-bindings/src/framebuffer.rs
@@ -0,0 +1,189 @@
+use crate::texture::Texture;
+use crate::MaybeCurrentContextWithFns;
+
+#[derive(Debug, Clone)]
+pub struct Framebuffer
+{
+    inner: crate::sys::types::GLuint,
+}
+
+impl Framebuffer
+{
+    #[must_use]
+    pub fn new(current_context: &MaybeCurrentContextWithFns) -> Self
+    {
+        let mut inner = 0;
+
+        unsafe {
+            current_context.fns().GenFramebuffers(1, &raw mut inner);
+        }
+
+        Self { inner }
+    }
+
+    /// Attaches a texture object as a logical buffer of this framebuffer object.
+    pub fn attach_texture(
+        &self,
+        current_context: &MaybeCurrentContextWithFns,
+        attachment: Attachment,
+        texture: Texture,
+        texture_mipmap_level: u16,
+    )
+    {
+        unsafe {
+            current_context.fns().NamedFramebufferTexture(
+                self.inner,
+                attachment.into_gl(),
+                texture.into_raw(),
+                texture_mipmap_level.into(),
+            );
+        }
+    }
+
+    /// Specifies which color buffer is to be drawn into when colors are written to this
+    /// framebuffer object.
+    ///
+    /// If `buffer` is `None`, no color buffer will be written into.
+    pub fn set_draw_buffer(
+        &self,
+        current_context: &MaybeCurrentContextWithFns,
+        buffer: Option<ColorAttachment>,
+    )
+    {
+        unsafe {
+            current_context.fns().NamedFramebufferDrawBuffer(
+                self.inner,
+                buffer
+                    .map(ColorAttachment::into_gl)
+                    .unwrap_or(crate::sys::NONE),
+            );
+        }
+    }
+
+    pub fn delete(self, current_context: &MaybeCurrentContextWithFns)
+    {
+        unsafe {
+            current_context
+                .fns()
+                .DeleteFramebuffers(1, &raw const self.inner);
+        }
+    }
+
+    pub fn from_raw(raw: u32) -> Self
+    {
+        Self { inner: raw }
+    }
+
+    pub fn into_raw(self) -> u32
+    {
+        self.inner
+    }
+}
+
+/// Binds a framebuffer to a framebuffer target.
+///
+/// If `framebuffer` is `None`, breaks the existing binding of a framebuffer object to
+/// the framebuffer target `target`.
+pub fn bind(
+    current_context: &MaybeCurrentContextWithFns,
+    target: Target,
+    framebuffer: Option<&Framebuffer>,
+)
+{
+    unsafe {
+        current_context.fns().BindFramebuffer(
+            target.into_gl(),
+            framebuffer
+                .map(|framebuffer| framebuffer.inner)
+                .unwrap_or(0),
+        );
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum Target
+{
+    Draw,
+    Read,
+    DrawAndRead,
+}
+
+impl Target
+{
+    fn into_gl(self) -> crate::sys::types::GLenum
+    {
+        match self {
+            Self::Draw => crate::sys::DRAW_FRAMEBUFFER,
+            Self::Read => crate::sys::READ_FRAMEBUFFER,
+            Self::DrawAndRead => crate::sys::FRAMEBUFFER,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[non_exhaustive]
+pub enum Attachment
+{
+    Color(ColorAttachment),
+    Depth,
+    Stencil,
+    DepthStencil,
+}
+
+impl Attachment
+{
+    fn into_gl(self) -> crate::sys::types::GLenum
+    {
+        match self {
+            Self::Color(color_attachment) => color_attachment.into_gl(),
+            Self::Depth => crate::sys::DEPTH_ATTACHMENT,
+            Self::Stencil => crate::sys::STENCIL_ATTACHMENT,
+            Self::DepthStencil => crate::sys::DEPTH_STENCIL_ATTACHMENT,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct ColorAttachment(pub u8);
+
+impl ColorAttachment
+{
+    fn into_gl(self) -> crate::sys::types::GLenum
+    {
+        match self.0 {
+            0 => crate::sys::COLOR_ATTACHMENT0,
+            1 => crate::sys::COLOR_ATTACHMENT1,
+            10 => crate::sys::COLOR_ATTACHMENT10,
+            11 => crate::sys::COLOR_ATTACHMENT11,
+            12 => crate::sys::COLOR_ATTACHMENT12,
+            13 => crate::sys::COLOR_ATTACHMENT13,
+            14 => crate::sys::COLOR_ATTACHMENT14,
+            15 => crate::sys::COLOR_ATTACHMENT15,
+            16 => crate::sys::COLOR_ATTACHMENT16,
+            17 => crate::sys::COLOR_ATTACHMENT17,
+            18 => crate::sys::COLOR_ATTACHMENT18,
+            19 => crate::sys::COLOR_ATTACHMENT19,
+            2 => crate::sys::COLOR_ATTACHMENT2,
+            20 => crate::sys::COLOR_ATTACHMENT20,
+            21 => crate::sys::COLOR_ATTACHMENT21,
+            22 => crate::sys::COLOR_ATTACHMENT22,
+            23 => crate::sys::COLOR_ATTACHMENT23,
+            24 => crate::sys::COLOR_ATTACHMENT24,
+            25 => crate::sys::COLOR_ATTACHMENT25,
+            26 => crate::sys::COLOR_ATTACHMENT26,
+            27 => crate::sys::COLOR_ATTACHMENT27,
+            28 => crate::sys::COLOR_ATTACHMENT28,
+            29 => crate::sys::COLOR_ATTACHMENT29,
+            3 => crate::sys::COLOR_ATTACHMENT3,
+            30 => crate::sys::COLOR_ATTACHMENT30,
+            31 => crate::sys::COLOR_ATTACHMENT31,
+            4 => crate::sys::COLOR_ATTACHMENT4,
+            5 => crate::sys::COLOR_ATTACHMENT5,
+            6 => crate::sys::COLOR_ATTACHMENT6,
+            7 => crate::sys::COLOR_ATTACHMENT7,
+            8 => crate::sys::COLOR_ATTACHMENT8,
+            9 => crate::sys::COLOR_ATTACHMENT9,
+            _ => panic!("Invalid color attachment index. Must be < 32"),
+        }
+    }
+}