Error out when DrawRect command is invoked on a pipeline with multipl…

…e vertex buffers attached (google#570)

* Error out when DrawRect command is invoked on a pipeline with multiple vertex buffers attached

* review comment

* review comment-2

src/amberscript/parser.cc

@@ -1005,6 +1005,12 @@ Result Parser::ParseRun() {
     if (!pipeline->IsGraphics())
       return Result("RUN command requires graphics pipeline");
 
+    if (pipeline->GetVertexBuffers().size() > 1) {
+      return Result(
+          "RUN DRAW_RECT is not supported in a pipeline with more than one "
+          "vertex buffer attached");
+    }
+
     token = tokenizer_->NextToken();
     if (token->IsEOS() || token->IsEOL())
       return Result("RUN DRAW_RECT command requires parameters");

src/vkscript/command_parser.cc

@@ -254,6 +254,12 @@ Result CommandParser::ProcessDrawRect() {
   auto cmd = MakeUnique<DrawRectCommand>(pipeline_, pipeline_data_);
   cmd->SetLine(tokenizer_->GetCurrentLine());
 
+  if (pipeline_->GetVertexBuffers().size() > 1) {
+    return Result(
+        "draw rect command is not supported in a pipeline with more than one "
+        "vertex buffer attached");
+  }
+
   auto token = tokenizer_->NextToken();
   while (token->IsString()) {
     std::string str = token->AsString();

tests/cases/draw_rect_with_two_vertex_data_attached.expect_fail.amber

@@ -0,0 +1,74 @@
+#!amber
+# Copyright 2019 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 vtex_shader GLSL
+#version 430
+
+layout(location = 0) in vec3 position;
+layout(location = 1) in vec4 ver_color;
+layout(location = 0) out vec4 frag_color;
+
+
+void main() {
+  gl_Position = vec4(position, 1.0);
+  frag_color = ver_color;
+}
+END
+
+SHADER fragment frag_shader GLSL
+#version 430
+
+layout(location = 0) in vec4 frag_color;
+layout(location = 0) out vec4 final_color;
+
+void main() {
+  final_color = frag_color;
+}
+END
+
+BUFFER position_buf DATA_TYPE vec3<float> DATA
+-1  1 0
+-1 -1 0
+ 1  1 0
+ 1 -1 0
+-1 -1 0
+ 1  1 0
+END
+
+BUFFER vert_color_buf DATA_TYPE R8G8B8A8_UNORM DATA
+255   0   0 255
+255   0   0 255
+255   0   0 255
+255   0   0 255
+255   0   0 255
+255   0   0 255
+END
+
+BUFFER framebuffer FORMAT B8G8R8A8_UNORM
+
+PIPELINE graphics pipeline
+  ATTACH vtex_shader
+  ATTACH frag_shader
+
+  VERTEX_DATA position_buf LOCATION 0
+  VERTEX_DATA vert_color_buf LOCATION 1
+
+  FRAMEBUFFER_SIZE 250 250
+  BIND BUFFER framebuffer AS color LOCATION 0
+
+END
+
+RUN pipeline DRAW_RECT POS 100 100 SIZE 100 100
+EXPECT framebuffer IDX 100 100 SIZE 100 100 EQ_RGBA 255 0 0 255

tests/cases/draw_rect_with_two_vertex_data_attached.expect_fail.vkscript

@@ -0,0 +1,96 @@
+# Copyright 2019 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.
+
+[require]
+
+[vertex shader]
+#version 450
+
+layout(location = 0) in vec4 position;
+layout(location = 1) in vec4 vert_color;
+layout(location = 0) out vec4 final_color;
+
+void main() {
+  gl_Position = position;
+  final_color = vert_color;
+}
+
+[fragment shader]
+#version 450
+
+layout(location = 0) in vec4 frag_color;
+layout(location = 0) out vec4 final_color;
+
+void main() {
+  final_color = frag_color;
+}
+
+[vertex data]
+#        position     vert_color
+     0/R8G8_SNORM 1/R8G8B8_UNORM
+
+#           Red for entire frame
+#         R8   G8     R8  G8  B8
+        -128 -128    255   0   0
+         127  127    255   0   0
+        -128  127    255   0   0
+
+        -128 -128    255   0   0
+         127  127    255   0   0
+         127 -128    255   0   0
+
+#           Green for half frame
+#         R8   G8     R8  G8  B8
+           0 -128      0 255   0
+         127  127      0 255   0
+           0  127      0 255   0
+
+           0 -128      0 255   0
+         127  127      0 255   0
+         127 -128      0 255   0
+
+#         Blue for quarter frame
+#         R8   G8     R8  G8  B8
+        -128    0      0   0 255
+           0  127      0   0 255
+        -128  127      0   0 255
+
+        -128    0      0   0 255
+           0  127      0   0 255
+           0    0      0   0 255
+
+#  Mixed color for quarter frame
+#         R8   G8     R8  G8  B8
+           0    0    127 127 127
+         127  127    127 127 127
+           0  127    127 127 127
+
+           0    0    127 127 127
+         127  127    127 127 127
+         127    0    127 127 127
+
+[test]
+clear
+
+draw rect -1 -1 2 2
+relative probe rect rgb (0.0, 0.0, 0.5, 0.5) (1.0, 0, 0)
+relative probe rect rgb (0.5, 0.0, 0.5, 0.5) (0, 1.0, 0)
+relative probe rect rgb (0.0, 0.5, 0.5, 0.5) (0, 0, 1.0)
+relative probe rect rgb (0.5, 0.5, 0.5, 0.5) (0.5, 0.5, 0.5)
+
+draw arrays TRIANGLE_LIST 0 24
+relative probe rect rgb (0.0, 0.0, 0.5, 0.5) (1.0, 0, 0)
+relative probe rect rgb (0.5, 0.0, 0.5, 0.5) (0, 1.0, 0)
+relative probe rect rgb (0.0, 0.5, 0.5, 0.5) (0, 0, 1.0)
+relative probe rect rgb (0.5, 0.5, 0.5, 0.5) (0.5, 0.5, 0.5)