Add ViewportOrientation test

src/backend/metal/ShaderModuleMTL.mm

@@ -49,6 +49,10 @@ namespace backend { namespace metal {
                                                               const PipelineLayout* layout) const {
         spirv_cross::CompilerMSL compiler(mSpirv);
 
+        spirv_cross::CompilerGLSL::Options options_glsl;
+        options_glsl.vertex.flip_vert_y = true;
+        compiler.spirv_cross::CompilerGLSL::set_options(options_glsl);
+
         // By default SPIRV-Cross will give MSL resources indices in increasing order.
         // To make the MSL indices match the indices chosen in the PipelineLayout, we build
         // a table of MSLResourceBinding to give to SPIRV-Cross

src/tests/CMakeLists.txt

@@ -80,6 +80,7 @@ add_executable(nxt_end2end_tests
     ${END2END_TESTS_DIR}/PrimitiveTopologyTests.cpp
     ${END2END_TESTS_DIR}/PushConstantTests.cpp
     ${END2END_TESTS_DIR}/RenderPassLoadOpTests.cpp
+    ${END2END_TESTS_DIR}/ViewportOrientationTests.cpp
     ${TESTS_DIR}/End2EndTestsMain.cpp
     ${TESTS_DIR}/NXTTest.cpp
     ${TESTS_DIR}/NXTTest.h

src/tests/end2end/ViewportOrientationTests.cpp

@@ -0,0 +1,63 @@
+// Copyright 2017 The NXT 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
+//
+//     http://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.
+
+#include "tests/NXTTest.h"
+
+#include "utils/NXTHelpers.h"
+
+class ViewportOrientationTests : public NXTTest {};
+
+// Test that the pixel in viewport coordinate (-1, -1) matches texel (0, 0)
+TEST_P(ViewportOrientationTests, OriginAt0x0) {
+    utils::BasicFramebuffer fb = utils::CreateBasicFramebuffer(device, 2, 2);
+
+    nxt::ShaderModule vsModule = utils::CreateShaderModule(device, nxt::ShaderStage::Vertex, R"(
+        #version 450
+        void main() {
+            gl_Position = vec4(-0.5f, -0.5f, 0.0f, 1.0f);
+        })"
+    );
+
+    nxt::ShaderModule fsModule = utils::CreateShaderModule(device, nxt::ShaderStage::Fragment, R"(
+        #version 450
+        layout(location = 0) out vec4 fragColor;
+        void main() {
+            fragColor = vec4(0.0f, 1.0f, 0.0f, 1.0f);
+        })");
+
+    nxt::RenderPipeline pipeline = device.CreateRenderPipelineBuilder()
+        .SetSubpass(fb.renderPass, 0)
+        .SetStage(nxt::ShaderStage::Vertex, vsModule, "main")
+        .SetStage(nxt::ShaderStage::Fragment, fsModule, "main")
+        .SetPrimitiveTopology(nxt::PrimitiveTopology::PointList)
+        .GetResult();
+
+    nxt::CommandBuffer commands = device.CreateCommandBufferBuilder()
+        .BeginRenderPass(fb.renderPass, fb.framebuffer)
+        .BeginRenderSubpass()
+        .SetRenderPipeline(pipeline)
+        .DrawArrays(1, 1, 0, 0)
+        .EndRenderSubpass()
+        .EndRenderPass()
+        .GetResult();
+
+    queue.Submit(1, &commands);
+
+    EXPECT_PIXEL_RGBA8_EQ(RGBA8(0, 255, 0, 255), fb.color, 0, 0);
+    EXPECT_PIXEL_RGBA8_EQ(RGBA8(0, 0, 0, 0), fb.color, 0, 1);
+    EXPECT_PIXEL_RGBA8_EQ(RGBA8(0, 0, 0, 0), fb.color, 1, 0);
+    EXPECT_PIXEL_RGBA8_EQ(RGBA8(0, 0, 0, 0), fb.color, 1, 1);
+}
+
+NXT_INSTANTIATE_TEST(ViewportOrientationTests, D3D12Backend, MetalBackend, OpenGLBackend, VulkanBackend)