From 6f35786b847b934ff2ab02cac97d9972b1d0345c Mon Sep 17 00:00:00 2001
From: Joshua Barretto <joshua.s.barretto@gmail.com>
Date: Mon, 19 Aug 2019 18:23:47 +0100
Subject: [PATCH] Added Instances construct

---
 voxygen/src/render/instances.rs | 32 ++++++++++++++++++++++++++++++++
 voxygen/src/render/mod.rs       |  1 +
 voxygen/src/render/renderer.rs  | 23 +++++++++++++++++++++++
 3 files changed, 56 insertions(+)
 create mode 100644 voxygen/src/render/instances.rs

diff --git a/voxygen/src/render/instances.rs b/voxygen/src/render/instances.rs
new file mode 100644
index 0000000000..da5f62b83b
--- /dev/null
+++ b/voxygen/src/render/instances.rs
@@ -0,0 +1,32 @@
+use super::{gfx_backend, RenderError};
+use gfx::{
+    self,
+    buffer::Role,
+    memory::{Bind, Usage},
+    Factory,
+};
+
+/// Represents a mesh that has been sent to the GPU.
+pub struct Instances<T: Copy + gfx::traits::Pod> {
+    pub ibuf: gfx::handle::Buffer<gfx_backend::Resources, T>,
+}
+
+impl<T: Copy + gfx::traits::Pod> Instances<T> {
+    pub fn new(factory: &mut gfx_backend::Factory, len: usize) -> Result<Self, RenderError> {
+        Ok(Self {
+            ibuf: factory
+                .create_buffer(len, Role::Vertex, Usage::Data, Bind::TRANSFER_DST)
+                .map_err(|err| RenderError::BufferCreationError(err))?,
+        })
+    }
+
+    pub fn update(
+        &mut self,
+        encoder: &mut gfx::Encoder<gfx_backend::Resources, gfx_backend::CommandBuffer>,
+        instances: &[T],
+    ) -> Result<(), RenderError> {
+        encoder
+            .update_buffer(&self.ibuf, instances, 0)
+            .map_err(|err| RenderError::UpdateError(err))
+    }
+}
diff --git a/voxygen/src/render/mod.rs b/voxygen/src/render/mod.rs
index ec371da2e8..3fd92a63f7 100644
--- a/voxygen/src/render/mod.rs
+++ b/voxygen/src/render/mod.rs
@@ -1,4 +1,5 @@
 pub mod consts;
+pub mod instances;
 pub mod mesh;
 pub mod model;
 pub mod pipelines;
diff --git a/voxygen/src/render/renderer.rs b/voxygen/src/render/renderer.rs
index 0294364274..c9d516ef8e 100644
--- a/voxygen/src/render/renderer.rs
+++ b/voxygen/src/render/renderer.rs
@@ -1,6 +1,7 @@
 use super::{
     consts::Consts,
     gfx_backend,
+    instances::Instances,
     mesh::Mesh,
     model::{DynamicModel, Model},
     pipelines::{figure, fluid, postprocess, skybox, sprite, terrain, ui, Globals, Light},
@@ -435,6 +436,28 @@ impl Renderer {
         );
     }
 
+    /// Queue the rendering of the provided terrain chunk model in the upcoming frame.
+    pub fn render_sprites(
+        &mut self,
+        model: &Model<sprite::SpritePipeline>,
+        globals: &Consts<Globals>,
+        instances: &Instances<sprite::Instance>,
+        lights: &Consts<Light>,
+    ) {
+        self.encoder.draw(
+            &model.slice,
+            &self.sprite_pipeline.pso,
+            &sprite::pipe::Data {
+                vbuf: model.vbuf.clone(),
+                ibuf: instances.ibuf.clone(),
+                globals: globals.buf.clone(),
+                lights: lights.buf.clone(),
+                tgt_color: self.tgt_color_view.clone(),
+                tgt_depth: self.tgt_depth_view.clone(),
+            },
+        );
+    }
+
     /// Queue the rendering of the provided UI element in the upcoming frame.
     pub fn render_ui_element(
         &mut self,