feat(opengl-bindings): add Buffer init fn

1 files changed, 50 insertions, 18 deletions

diff --git a/opengl-bindings/src/buffer.rs b/opengl-bindings/src/buffer.rs
index 4c91649..3bb6c48 100644
--- a/opengl-bindings/src/buffer.rs
+++ b/opengl-bindings/src/buffer.rs
@@ -27,6 +27,35 @@ impl<Item: ReprC> Buffer<Item>
         Self { buf: buffer, _pd: PhantomData }
     }
 
+    /// Initializes this buffer with a size and a usage.
+    ///
+    /// # Errors
+    /// Returns `Err` if the size (in bytes) is too large.
+    pub fn init(
+        &self,
+        current_context: &CurrentContextWithFns<'_>,
+        size: usize,
+        usage: Usage,
+    ) -> Result<(), Error>
+    {
+        let size: crate::sys::types::GLsizeiptr =
+            size.try_into().map_err(|_| Error::SizeTooLarge {
+                size,
+                max_size: crate::sys::types::GLsizeiptr::MAX as usize,
+            })?;
+
+        unsafe {
+            current_context.fns().NamedBufferData(
+                self.buf,
+                size,
+                null(),
+                usage.into_gl(),
+            );
+        }
+
+        Ok(())
+    }
+
     /// Stores items in this buffer.
     ///
     /// # Errors
@@ -41,12 +70,10 @@ impl<Item: ReprC> Buffer<Item>
         let total_size = size_of_val(items);
 
         let total_size: crate::sys::types::GLsizeiptr =
-            total_size
-                .try_into()
-                .map_err(|_| Error::TotalItemsSizeTooLarge {
-                    total_size,
-                    max_total_size: crate::sys::types::GLsizeiptr::MAX as usize,
-                })?;
+            total_size.try_into().map_err(|_| Error::SizeTooLarge {
+                size: total_size,
+                max_size: crate::sys::types::GLsizeiptr::MAX as usize,
+            })?;
 
         unsafe {
             current_context.fns().NamedBufferData(
@@ -82,12 +109,10 @@ impl<Item: ReprC> Buffer<Item>
         let total_size = size_of::<Item>() * values.len();
 
         let total_size: crate::sys::types::GLsizeiptr =
-            total_size
-                .try_into()
-                .map_err(|_| Error::TotalItemsSizeTooLarge {
-                    total_size,
-                    max_total_size: crate::sys::types::GLsizeiptr::MAX as usize,
-                })?;
+            total_size.try_into().map_err(|_| Error::SizeTooLarge {
+                size: total_size,
+                max_size: crate::sys::types::GLsizeiptr::MAX as usize,
+            })?;
 
         unsafe {
             current_context.fns().NamedBufferData(
@@ -160,15 +185,22 @@ impl Usage
     }
 }
 
+#[derive(Debug)]
+#[repr(u32)]
+pub enum BindingTarget
+{
+    AtomicCounterBuffer = crate::sys::ATOMIC_COUNTER_BUFFER,
+    TransformFeedbackBuffer = crate::sys::TRANSFORM_FEEDBACK_BUFFER,
+    UniformBuffer = crate::sys::UNIFORM_BUFFER,
+    ShaderStorageBuffer = crate::sys::SHADER_STORAGE_BUFFER,
+}
+
 #[derive(Debug, thiserror::Error)]
 pub enum Error
 {
-    #[error(
-        "Total size of items ({total_size}) is too large. Must be < {max_total_size}"
-    )]
-    TotalItemsSizeTooLarge
+    #[error("Size ({size}) is too large. Must be < {max_size}")]
+    SizeTooLarge
     {
-        total_size: usize,
-        max_total_size: usize,
+        size: usize, max_size: usize
     },
 }