Use proper index type based on index buffer format (#981)

* Use proper index type based on index buffer format

Amber was assuming the index buffer to always be uint32. Now the
buffer format is used to determine the index type when binding
the index buffer in Vulkan.

* Exclude 8 bit indices test from SwiftShader runs

6 files changed, 159 insertions, 1 deletions

diff --git a/src/vulkan/index_buffer.cc b/src/vulkan/index_buffer.cc
index b651427..30b223d 100644
--- a/src/vulkan/index_buffer.cc
+++ b/src/vulkan/index_buffer.cc
@@ -36,6 +36,15 @@ Result IndexBuffer::SendIndexData(CommandBuffer* command, Buffer* buffer) {
   if (buffer->ElementCount() == 0)
     return Result("IndexBuffer::SendIndexData |buffer| is empty");
 
+  if (buffer->GetFormat()->IsUint32())
+    index_type_ = VK_INDEX_TYPE_UINT32;
+  else if (buffer->GetFormat()->IsUint16())
+    index_type_ = VK_INDEX_TYPE_UINT16;
+  else if (buffer->GetFormat()->IsUint8())
+    index_type_ = VK_INDEX_TYPE_UINT8_EXT;
+  else
+    return Result("IndexBuffer::SendIndexData unexpected index buffer format");
+
   transfer_buffer_ =
       MakeUnique<TransferBuffer>(device_, buffer->GetSizeInBytes(), nullptr);
   Result r = transfer_buffer_->AddUsageFlags(VK_BUFFER_USAGE_INDEX_BUFFER_BIT |
@@ -62,7 +71,7 @@ Result IndexBuffer::BindToCommandBuffer(CommandBuffer* command) {
 
   device_->GetPtrs()->vkCmdBindIndexBuffer(command->GetVkCommandBuffer(),
                                            transfer_buffer_->GetVkBuffer(), 0,
-                                           VK_INDEX_TYPE_UINT32);
+                                           index_type_);
   return {};
 }
 
diff --git a/src/vulkan/index_buffer.h b/src/vulkan/index_buffer.h
index 2d21330..4b22ebe 100644
--- a/src/vulkan/index_buffer.h
+++ b/src/vulkan/index_buffer.h
@@ -46,6 +46,7 @@ class IndexBuffer {
  private:
   Device* device_ = nullptr;
   std::unique_ptr<TransferBuffer> transfer_buffer_;
+  VkIndexType index_type_;
 };
 
 }  // namespace vulkan
diff --git a/tests/cases/draw_indexed_uint16.amber b/tests/cases/draw_indexed_uint16.amber
new file mode 100644
index 0000000..f42e2b5
--- /dev/null
+++ b/tests/cases/draw_indexed_uint16.amber
@@ -0,0 +1,48 @@
+#!amber
+# Copyright 2022 The Amber Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+SHADER vertex vert_shader PASSTHROUGH
+SHADER fragment frag_shader GLSL
+#version 430
+layout(location = 0) out vec4 color_out;
+void main() {
+  color_out = vec4(0.0, 1.0, 0.0, 1.0);
+}
+END
+
+BUFFER position DATA_TYPE vec4<float> DATA
+-1.0  1.0 0.0 1.0
+ 1.0  1.0 0.0 1.0
+ 1.0 -1.0 0.0 1.0
+-1.0 -1.0 0.0 1.0
+END
+
+BUFFER indices DATA_TYPE uint16 DATA
+3 2 1 0
+END
+
+IMAGE framebuffer FORMAT B8G8R8A8_UNORM DIM_2D WIDTH 64 HEIGHT 64
+
+PIPELINE graphics pipeline
+  ATTACH vert_shader
+  ATTACH frag_shader
+  VERTEX_DATA position LOCATION 0
+  INDEX_DATA indices
+  FRAMEBUFFER_SIZE 64 64
+  BIND BUFFER framebuffer AS color LOCATION 0
+END
+
+RUN pipeline DRAW_ARRAY AS TRIANGLE_FAN INDEXED START_IDX 0 COUNT 4
+EXPECT framebuffer IDX 0 0 SIZE 64 64 EQ_RGBA 0 255 0 255
diff --git a/tests/cases/draw_indexed_uint32.amber b/tests/cases/draw_indexed_uint32.amber
new file mode 100644
index 0000000..3a2eac2
--- /dev/null
+++ b/tests/cases/draw_indexed_uint32.amber
@@ -0,0 +1,48 @@
+#!amber
+# Copyright 2022 The Amber Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+SHADER vertex vert_shader PASSTHROUGH
+SHADER fragment frag_shader GLSL
+#version 430
+layout(location = 0) out vec4 color_out;
+void main() {
+  color_out = vec4(0.0, 1.0, 0.0, 1.0);
+}
+END
+
+BUFFER position DATA_TYPE vec4<float> DATA
+-1.0  1.0 0.0 1.0
+ 1.0  1.0 0.0 1.0
+ 1.0 -1.0 0.0 1.0
+-1.0 -1.0 0.0 1.0
+END
+
+BUFFER indices DATA_TYPE uint32 DATA
+3 2 1 0
+END
+
+IMAGE framebuffer FORMAT B8G8R8A8_UNORM DIM_2D WIDTH 64 HEIGHT 64
+
+PIPELINE graphics pipeline
+  ATTACH vert_shader
+  ATTACH frag_shader
+  VERTEX_DATA position LOCATION 0
+  INDEX_DATA indices
+  FRAMEBUFFER_SIZE 64 64
+  BIND BUFFER framebuffer AS color LOCATION 0
+END
+
+RUN pipeline DRAW_ARRAY AS TRIANGLE_FAN INDEXED START_IDX 0 COUNT 4
+EXPECT framebuffer IDX 0 0 SIZE 64 64 EQ_RGBA 0 255 0 255
diff --git a/tests/cases/draw_indexed_uint8.amber b/tests/cases/draw_indexed_uint8.amber
new file mode 100644
index 0000000..a038233
--- /dev/null
+++ b/tests/cases/draw_indexed_uint8.amber
@@ -0,0 +1,50 @@
+#!amber
+# Copyright 2022 The Amber Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+DEVICE_EXTENSION VK_EXT_index_type_uint8
+
+SHADER vertex vert_shader PASSTHROUGH
+SHADER fragment frag_shader GLSL
+#version 430
+layout(location = 0) out vec4 color_out;
+void main() {
+  color_out = vec4(0.0, 1.0, 0.0, 1.0);
+}
+END
+
+BUFFER position DATA_TYPE vec4<float> DATA
+-1.0  1.0 0.0 1.0
+ 1.0  1.0 0.0 1.0
+ 1.0 -1.0 0.0 1.0
+-1.0 -1.0 0.0 1.0
+END
+
+BUFFER indices DATA_TYPE uint8 DATA
+3 2 1 0
+END
+
+IMAGE framebuffer FORMAT B8G8R8A8_UNORM DIM_2D WIDTH 64 HEIGHT 64
+
+PIPELINE graphics pipeline
+  ATTACH vert_shader
+  ATTACH frag_shader
+  VERTEX_DATA position LOCATION 0
+  INDEX_DATA indices
+  FRAMEBUFFER_SIZE 64 64
+  BIND BUFFER framebuffer AS color LOCATION 0
+END
+
+RUN pipeline DRAW_ARRAY AS TRIANGLE_FAN INDEXED START_IDX 0 COUNT 4
+EXPECT framebuffer IDX 0 0 SIZE 64 64 EQ_RGBA 0 255 0 255
diff --git a/tests/run_tests.py b/tests/run_tests.py
index 6cd8fc3..23789f6 100755
--- a/tests/run_tests.py
+++ b/tests/run_tests.py
@@ -98,6 +98,8 @@ SUPPRESSIONS_SWIFTSHADER = [
   "draw_rectangles_depth_test_x8d24.amber",
   # Tessellation not supported
   "tessellation_isolines.amber",
+  # 8 bit indices not supported
+  "draw_indexed_uint8.amber",
 ]
 
 OPENCL_CASES = [