1 files changed, 120 insertions, 0 deletions
diff --git a/engine/src/renderer/opengl/graphics_mesh.rs b/engine/src/renderer/opengl/graphics_mesh.rs
new file mode 100644
index 0000000..9b929c0
--- /dev/null
+++ b/engine/src/renderer/opengl/graphics_mesh.rs
@@ -0,0 +1,120 @@
+use opengl_bindings::buffer::{Buffer as GlBuffer, Usage as GlBufferUsage};
+use opengl_bindings::vertex_array::{
+    DataType as GlVertexArrayDataType,
+    VertexArray as GlVertexArray,
+};
+use opengl_bindings::CurrentContextWithFns as GlCurrentContextWithFns;
+
+use crate::mesh::Mesh;
+use crate::renderer::opengl::vertex::{
+    AttributeComponentType as VertexAttributeComponentType,
+    Vertex as RendererVertex,
+};
+
+#[derive(Debug)]
+pub struct GraphicsMesh
+{
+    /// Vertex and index buffer has to live as long as the vertex array
+    _vertex_buffer: GlBuffer<RendererVertex>,
+    pub index_buffer: Option<GlBuffer<u32>>,
+    pub element_cnt: u32,
+    pub vertex_arr: GlVertexArray,
+}
+
+impl GraphicsMesh
+{
+    #[tracing::instrument(skip_all)]
+    pub fn new(
+        current_context: &GlCurrentContextWithFns<'_>,
+        mesh: &Mesh,
+    ) -> Result<Self, Error>
+    {
+        tracing::trace!(
+            "Creating vertex array, vertex buffer{}",
+            if mesh.indices().is_some() {
+                " and index buffer"
+            } else {
+                ""
+            }
+        );
+
+        let vertex_arr = GlVertexArray::new(current_context);
+        let vertex_buffer = GlBuffer::new(current_context);
+
+        vertex_buffer
+            .store_mapped(
+                current_context,
+                mesh.vertices(),
+                GlBufferUsage::Static,
+                |vertex| RendererVertex {
+                    pos: vertex.pos.into(),
+                    texture_coords: vertex.texture_coords.into(),
+                    normal: vertex.normal.into(),
+                },
+            )
+            .map_err(Error::StoreVerticesFailed)?;
+
+        vertex_arr.bind_vertex_buffer(current_context, 0, &vertex_buffer, 0);
+
+        let mut offset = 0u32;
+
+        for attrib in RendererVertex::attrs() {
+            vertex_arr.enable_attrib(current_context, attrib.index);
+
+            vertex_arr.set_attrib_format(
+                current_context,
+                attrib.index,
+                match attrib.component_type {
+                    VertexAttributeComponentType::Float => GlVertexArrayDataType::Float,
+                },
+                false,
+                offset,
+            );
+
+            vertex_arr.set_attrib_vertex_buf_binding(current_context, attrib.index, 0);
+
+            offset += attrib.component_size * attrib.component_cnt as u32;
+        }
+
+        if let Some(indices) = mesh.indices() {
+            let index_buffer = GlBuffer::new(current_context);
+
+            index_buffer
+                .store(current_context, indices, GlBufferUsage::Static)
+                .map_err(Error::StoreIndicesFailed)?;
+
+            vertex_arr.bind_element_buffer(current_context, &index_buffer);
+
+            return Ok(Self {
+                _vertex_buffer: vertex_buffer,
+                index_buffer: Some(index_buffer),
+                element_cnt: indices
+                    .len()
+                    .try_into()
+                    .expect("Mesh index count does not fit into a 32-bit unsigned int"),
+                vertex_arr,
+            });
+        }
+
+        Ok(Self {
+            _vertex_buffer: vertex_buffer,
+            index_buffer: None,
+            element_cnt: mesh
+                .vertices()
+                .len()
+                .try_into()
+                .expect("Mesh vertex count does not fit into a 32-bit unsigned int"),
+            vertex_arr,
+        })
+    }
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error
+{
+    #[error("Failed to store vertices in vertex buffer")]
+    StoreVerticesFailed(#[source] opengl_bindings::buffer::Error),
+
+    #[error("Failed to store indices in index buffer")]
+    StoreIndicesFailed(#[source] opengl_bindings::buffer::Error),
+}