From 3d47436129e3e7a9caf3753415ac2c8cacd5bd01 Mon Sep 17 00:00:00 2001
From: Dzmitry Malyshau <kvarkus@gmail.com>
Date: Sun, 3 Feb 2019 15:51:54 -0500
Subject: [PATCH] rust: vertex/index binding

---
 gfx-examples/src/cube.rs          |  5 +++--
 wgpu-native/src/command/render.rs | 14 +++++++++++---
 wgpu-native/src/instance.rs       |  1 +
 wgpu-rs/src/lib.rs                | 19 +++++++++++++++++++
 4 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/gfx-examples/src/cube.rs b/gfx-examples/src/cube.rs
index d92a792b9..92be14edb 100644
--- a/gfx-examples/src/cube.rs
+++ b/gfx-examples/src/cube.rs
@@ -221,8 +221,9 @@ impl fw::Example for Cube {
                 depth_stencil_attachment: None,
             });
             rpass.set_pipeline(&self.pipeline);
-            //rpass.bind_groups();
-            //rpass.set_vertex_buffers();
+            rpass.set_bind_group(0, &self.bind_group);
+            rpass.set_index_buffer(&self.index_buf, 0);
+            rpass.set_vertex_buffers(&[(&self.vertex_buf, 0)]);
             rpass.draw(0..3, 0..1);
             rpass.end_pass();
         }
diff --git a/wgpu-native/src/command/render.rs b/wgpu-native/src/command/render.rs
index b5b42b801..62057071b 100644
--- a/wgpu-native/src/command/render.rs
+++ b/wgpu-native/src/command/render.rs
@@ -9,7 +9,7 @@ use crate::{
 
 use hal::command::RawCommandBuffer;
 
-use std::iter;
+use std::{iter, slice};
 
 
 pub struct RenderPass<B: hal::Backend> {
@@ -87,10 +87,19 @@ pub extern "C" fn wgpu_render_pass_set_index_buffer(
 
 #[no_mangle]
 pub extern "C" fn wgpu_render_pass_set_vertex_buffers(
-    pass_id: RenderPassId, buffers: &[BufferId], offsets: &[u32]
+    pass_id: RenderPassId,
+    buffer_ptr: *const BufferId,
+    offset_ptr: *const u32,
+    count: usize,
 ) {
     let mut pass_guard = HUB.render_passes.write();
     let buffer_guard = HUB.buffers.read();
+    let buffers = unsafe {
+        slice::from_raw_parts(buffer_ptr, count)
+    };
+    let offsets = unsafe {
+        slice::from_raw_parts(offset_ptr, count)
+    };
 
     let pass = pass_guard.get_mut(pass_id);
     for &id in buffers {
@@ -104,7 +113,6 @@ pub extern "C" fn wgpu_render_pass_set_vertex_buffers(
             .unwrap();
     }
 
-    assert_eq!(buffers.len(), offsets.len());
     let buffers = buffers
         .iter()
         .map(|&id| &buffer_guard.get(id).raw)
diff --git a/wgpu-native/src/instance.rs b/wgpu-native/src/instance.rs
index b8ec8655d..a66161ed1 100644
--- a/wgpu-native/src/instance.rs
+++ b/wgpu-native/src/instance.rs
@@ -50,6 +50,7 @@ pub extern "C" fn wgpu_instance_create_surface_from_winit(
     instance_id: InstanceId,
     window: &winit::Window,
 ) -> SurfaceId {
+    //TODO: remove these workarounds when porting on gfx-hal 0.2
     #[cfg(any(
         feature = "gfx-backend-vulkan",
         feature = "gfx-backend-dx11",
diff --git a/wgpu-rs/src/lib.rs b/wgpu-rs/src/lib.rs
index 2733996bd..ffa8b61c2 100644
--- a/wgpu-rs/src/lib.rs
+++ b/wgpu-rs/src/lib.rs
@@ -451,6 +451,25 @@ impl<'a> RenderPass<'a> {
         wgn::wgpu_render_pass_set_pipeline(self.id, pipeline.id);
     }
 
+    pub fn set_index_buffer(&mut self, buffer: &Buffer, offset: u32) {
+        wgn::wgpu_render_pass_set_index_buffer(self.id, buffer.id, offset);
+    }
+
+    pub fn set_vertex_buffers(&mut self, buffer_pairs: &[(&Buffer, u32)]) {
+        let mut buffers = Vec::new();
+        let mut offsets = Vec::new();
+        for &(buffer, offset) in buffer_pairs {
+            buffers.push(buffer.id);
+            offsets.push(offset);
+        }
+        wgn::wgpu_render_pass_set_vertex_buffers(
+            self.id,
+            buffers.as_ptr(),
+            offsets.as_ptr(),
+            buffer_pairs.len(),
+        );
+    }
+
     pub fn draw(&mut self, vertices: Range<u32>, instances: Range<u32>) {
         wgn::wgpu_render_pass_draw(
             self.id,