Merge #247

247: Add support for indirect drawing r=kvark a=dragly



Co-authored-by: Svenn-Arne Dragly <dragly@cognite.com>

ffi/wgpu.h

@@ -429,6 +429,7 @@ typedef uint32_t WGPUBufferUsage;
 #define WGPUBufferUsage_VERTEX 32
 #define WGPUBufferUsage_UNIFORM 64
 #define WGPUBufferUsage_STORAGE 128
+#define WGPUBufferUsage_INDIRECT 256
 #define WGPUBufferUsage_NONE 0
 #define WGPUBufferUsage_WRITE_ALL 2 + 8 + 128
 

wgpu-native/src/command/render.rs

@@ -379,6 +379,34 @@ pub extern "C" fn wgpu_render_pass_draw(
     }
 }
 
+#[no_mangle]
+pub extern "C" fn wgpu_render_pass_draw_indirect(
+    pass_id: RenderPassId,
+    indirect_buffer_id: BufferId,
+    indirect_offset: BufferAddress,
+) {
+    let mut token = Token::root();
+    let (mut pass_guard, _) = HUB.render_passes.write(&mut token);
+    let (buffer_guard, _) = HUB.buffers.read(&mut token);
+    let pass = &mut pass_guard[pass_id];
+    pass.is_ready().unwrap();
+
+    let buffer = pass
+        .trackers
+        .buffers
+        .use_extend(&*buffer_guard, indirect_buffer_id, (), BufferUsage::INDIRECT)
+        .unwrap();
+
+    unsafe {
+        pass.raw.draw_indirect(
+            &buffer.raw,
+            indirect_offset,
+            1,
+            0
+        );
+    }
+}
+
 #[no_mangle]
 pub extern "C" fn wgpu_render_pass_draw_indexed(
     pass_id: RenderPassId,
@@ -406,6 +434,34 @@ pub extern "C" fn wgpu_render_pass_draw_indexed(
     }
 }
 
+#[no_mangle]
+pub extern "C" fn wgpu_render_pass_draw_indexed_indirect(
+    pass_id: RenderPassId,
+    indirect_buffer_id: BufferId,
+    indirect_offset: BufferAddress,
+) {
+    let mut token = Token::root();
+    let (mut pass_guard, _) = HUB.render_passes.write(&mut token);
+    let (buffer_guard, _) = HUB.buffers.read(&mut token);
+    let pass = &mut pass_guard[pass_id];
+    pass.is_ready().unwrap();
+
+    let buffer = pass
+        .trackers
+        .buffers
+        .use_extend(&*buffer_guard, indirect_buffer_id, (), BufferUsage::INDIRECT)
+        .unwrap();
+
+    unsafe {
+        pass.raw.draw_indexed_indirect(
+            &buffer.raw,
+            indirect_offset,
+            1,
+            0
+        );
+    }
+}
+
 #[no_mangle]
 pub extern "C" fn wgpu_render_pass_set_pipeline(
     pass_id: RenderPassId,

wgpu-native/src/conv.rs

@@ -34,6 +34,9 @@ pub fn map_buffer_usage(
     if usage.contains(W::STORAGE) {
         hal_usage |= U::STORAGE;
     }
+    if usage.contains(W::INDIRECT) {
+        hal_usage |= U::INDIRECT;
+    }
 
     (hal_usage, hal_memory)
 }

wgpu-native/src/resource.rs

@@ -29,6 +29,7 @@ bitflags! {
         const VERTEX = 32;
         const UNIFORM = 64;
         const STORAGE = 128;
+        const INDIRECT = 256;
         const NONE = 0;
         const WRITE_ALL = 2 + 8 + 128;
     }