[glfw] Add static render test creator

Press F1 to create a render test for the current view.

The test will be created at the base folder (current if nothing is
provided) + /NNNN (the next free entry).

9 files changed, 256 insertions, 8 deletions

diff --git a/cmake/glfw.cmake b/cmake/glfw.cmake
index 89a7768ad3..d595518954 100644
--- a/cmake/glfw.cmake
+++ b/cmake/glfw.cmake
@@ -12,6 +12,8 @@ target_sources(mbgl-glfw
     PRIVATE platform/glfw/glfw_renderer_frontend.cpp
     PRIVATE platform/glfw/settings_json.hpp
     PRIVATE platform/glfw/settings_json.cpp
+    PRIVATE platform/glfw/test_writer.hpp
+    PRIVATE platform/glfw/test_writer.cpp
 )
 
 target_include_directories(mbgl-glfw
diff --git a/metrics/tests/binary-size/linux-gcc8/metrics.json b/metrics/tests/binary-size/linux-gcc8/metrics.json
index d8238e95f6..5b8e1f5bec 100644
--- a/metrics/tests/binary-size/linux-gcc8/metrics.json
+++ b/metrics/tests/binary-size/linux-gcc8/metrics.json
@@ -3,7 +3,7 @@
         [
             "mbgl-glfw",
             "/src/workspace/next-linux-gcc8-release/bin/mbgl-glfw",
-            7205192
+            7323976
         ],
         [
             "mbgl-offline",
diff --git a/metrics/tests/binary-size/macos-xcode11/metrics.json b/metrics/tests/binary-size/macos-xcode11/metrics.json
index 9a4ffebd13..41886e8caf 100644
--- a/metrics/tests/binary-size/macos-xcode11/metrics.json
+++ b/metrics/tests/binary-size/macos-xcode11/metrics.json
@@ -3,7 +3,7 @@
         [
             "mbgl-glfw",
             "/src/workspace/next-macos-xcode11-release/bin/mbgl-glfw",
-            5439932
+            5502420
         ],
         [
             "mbgl-offline",
diff --git a/next/platform/glfw/CMakeLists.txt b/next/platform/glfw/CMakeLists.txt
index e4c0920a44..b0263362a7 100644
--- a/next/platform/glfw/CMakeLists.txt
+++ b/next/platform/glfw/CMakeLists.txt
@@ -10,6 +10,7 @@ add_executable(
     ${MBGL_ROOT}/platform/glfw/glfw_gl_backend.cpp
     ${MBGL_ROOT}/platform/glfw/glfw_renderer_frontend.cpp
     ${MBGL_ROOT}/platform/glfw/settings_json.cpp
+    ${MBGL_ROOT}/platform/glfw/test_writer.cpp
 )
 
 target_include_directories(
@@ -30,6 +31,8 @@ target_link_libraries(
     PRIVATE
         ${GLFW_LIBRARIES}
         Mapbox::Base::Extras::args
+        Mapbox::Base::Extras::filesystem
+        Mapbox::Base::Extras::rapidjson
         Mapbox::Map
         OpenGL::GL
         mbgl-vendor-cheap-ruler-cpp
diff --git a/platform/glfw/glfw_view.cpp b/platform/glfw/glfw_view.cpp
index 74dda734c0..3d10f2c654 100644
--- a/platform/glfw/glfw_view.cpp
+++ b/platform/glfw/glfw_view.cpp
@@ -2,6 +2,7 @@
 #include "glfw_backend.hpp"
 #include "glfw_renderer_frontend.hpp"
 #include "ny_route.hpp"
+#include "test_writer.hpp"
 
 #include <mbgl/annotation/annotation.hpp>
 #include <mbgl/gfx/backend.hpp>
@@ -36,6 +37,7 @@
 
 #include <cassert>
 #include <cstdlib>
+#include <iostream>
 
 void glfwError(int error, const char *description) {
     mbgl::Log::Error(mbgl::Event::OpenGL, "GLFW error (%i): %s", error, description);
@@ -124,8 +126,8 @@ GLFWView::GLFWView(bool fullscreen_, bool benchmark_)
     printf("- Press `E` to insert an example building extrusion layer\n");
     printf("- Press `O` to toggle online connectivity\n");
     printf("- Press `Z` to cycle through north orientations\n");
-    printf("- Prezz `X` to cycle through the viewport modes\n");
-    printf("- Press `I` to Delete existing database and re-initialize\n");
+    printf("- Press `X` to cycle through the viewport modes\n");
+    printf("- Press `I` to delete existing database and re-initialize\n");
     printf("- Press `A` to cycle through Mapbox offices in the world + dateline monument\n");
     printf("- Press `B` to cycle through the color, stencil, and depth buffer\n");
     printf("- Press `D` to cycle through camera bounds: inside, crossing IDL at left, crossing IDL at right, and disabled\n");
@@ -138,10 +140,12 @@ GLFWView::GLFWView(bool fullscreen_, bool benchmark_)
     printf("- Press `K` to add a random custom runtime imagery annotation\n");
     printf("- Press `L` to add a random line annotation\n");
     printf("- Press `W` to pop the last-added annotation off\n");
-    printf("\n");
     printf("- Press `P` to pause tile requests\n");
-    printf("- `Control` + mouse drag to rotate\n");
-    printf("- `Shift` + mouse drag to tilt\n");
+    printf("\n");
+    printf("- Hold `Control` + mouse drag to rotate\n");
+    printf("- Hold `Shift` + mouse drag to tilt\n");
+    printf("\n");
+    printf("- Press `F1` to generate a render test for the current view\n");
     printf("\n");
     printf("- Press `Tab` to cycle through the map debug options\n");
     printf("- Press `Esc` to quit\n");
@@ -370,6 +374,20 @@ void GLFWView::onKey(GLFWwindow *window, int key, int /*scancode*/, int action,
                                          : mbgl::style::VisibilityType::Visible);
             }
         } break;
+        case GLFW_KEY_F1: {
+            bool success = TestWriter()
+                               .withInitialSize(mbgl::Size(view->width, view->height))
+                               .withStyle(view->map->getStyle())
+                               .withCameraOptions(view->map->getCameraOptions())
+                               .write(view->testDirectory);
+
+            if (success) {
+                mbgl::Log::Info(mbgl::Event::General, "Render test created!");
+            } else {
+                mbgl::Log::Error(mbgl::Event::General,
+                                 "Fail to create render test! Base directory does not exist or permission denied.");
+            }
+        } break;
         }
     }
 
diff --git a/platform/glfw/glfw_view.hpp b/platform/glfw/glfw_view.hpp
index 9233bddfb9..e9867f14da 100644
--- a/platform/glfw/glfw_view.hpp
+++ b/platform/glfw/glfw_view.hpp
@@ -29,6 +29,8 @@ public:
 
     mbgl::gfx::RendererBackend& getRendererBackend();
 
+    void setTestDirectory(std::string dir) { testDirectory = std::move(dir); };
+
     // Callback called when the user presses the key mapped to style change.
     // The expected action is to set a new style, different to the current one.
     void setChangeStyleCallback(std::function<void()> callback);
@@ -105,6 +107,8 @@ private:
     GLFWRendererFrontend* rendererFrontend = nullptr;
     std::unique_ptr<GLFWBackend> backend;
 
+    std::string testDirectory = ".";
+
     bool fullscreen = false;
     const bool benchmark = false;
     bool tracking = false;
diff --git a/platform/glfw/main.cpp b/platform/glfw/main.cpp
index 3c1e50e196..8f134804f0 100644
--- a/platform/glfw/main.cpp
+++ b/platform/glfw/main.cpp
@@ -43,7 +43,9 @@ int main(int argc, char *argv[]) {
     args::Flag benchmarkFlag(argumentParser, "benchmark", "Toggle benchmark", {'b', "benchmark"});
     args::Flag offlineFlag(argumentParser, "offline", "Toggle offline", {'o', "offline"});
 
-    args::ValueFlag<std::string> backendValue(argumentParser, "Backend", "Rendering backend", {"backend"});
+    args::ValueFlag<std::string> testDirValue(
+        argumentParser, "directory", "Root directory for test generation", {"testDir"});
+    args::ValueFlag<std::string> backendValue(argumentParser, "backend", "Rendering backend", {"backend"});
     args::ValueFlag<std::string> styleValue(argumentParser, "URL", "Map stylesheet", {'s', "style"});
     args::ValueFlag<std::string> cacheDBValue(argumentParser, "file", "Cache database file name", {'c', "cache"});
     args::ValueFlag<double> lonValue(argumentParser, "degrees", "Longitude", {'x', "lon"});
@@ -128,6 +130,8 @@ int main(int argc, char *argv[]) {
                    .withPitch(settings.pitch));
     map.setDebug(mbgl::MapDebugOptions(settings.debug));
 
+    if (testDirValue) view->setTestDirectory(args::get(testDirValue));
+
     view->setOnlineStatusCallback([&settings, fileSource]() {
         settings.online = !settings.online;
         fileSource->setOnlineStatus(settings.online);
diff --git a/platform/glfw/test_writer.cpp b/platform/glfw/test_writer.cpp
new file mode 100644
index 0000000000..d125170aed
--- /dev/null
+++ b/platform/glfw/test_writer.cpp
@@ -0,0 +1,188 @@
+#include "test_writer.hpp"
+
+#include <rapidjson/prettywriter.h>
+#include <rapidjson/stringbuffer.h>
+#include <rapidjson/writer.h>
+#include <ghc/filesystem.hpp>
+
+#include <cmath>
+#include <fstream>
+
+using Writer = rapidjson::PrettyWriter<rapidjson::StringBuffer>;
+
+class TestOperation {
+public:
+    virtual ~TestOperation() = default;
+
+    virtual void serialize(Writer& writer) const = 0;
+};
+
+class SetCamera final : public TestOperation {
+public:
+    SetCamera(const mbgl::CameraOptions& camera_) : camera(camera_) {}
+
+    void serialize(Writer& writer) const override {
+        if (camera.zoom) {
+            writer.StartArray();
+            writer.String("setZoom");
+            writer.Double(*camera.zoom);
+            writer.EndArray();
+        }
+
+        if (camera.bearing && *camera.bearing != 0.) {
+            writer.StartArray();
+            writer.String("setBearing");
+            writer.Double(*camera.bearing);
+            writer.EndArray();
+        }
+
+        if (camera.pitch && *camera.pitch != 0.) {
+            writer.StartArray();
+            writer.String("setPitch");
+            writer.Int(std::round(*camera.pitch));
+            writer.EndArray();
+        }
+
+        writer.StartArray();
+        writer.String("setCenter");
+        writer.StartArray();
+        writer.Double(camera.center->longitude());
+        writer.Double(camera.center->latitude());
+        writer.EndArray();
+        writer.EndArray();
+    }
+
+private:
+    mbgl::CameraOptions camera;
+};
+
+class SetStyle final : public TestOperation {
+public:
+    SetStyle(const mbgl::style::Style& style) : url(style.getURL()) {}
+
+    void serialize(Writer& writer) const override {
+        writer.StartArray();
+        writer.String("setStyle");
+        writer.String(url);
+        writer.EndArray();
+    }
+
+private:
+    std::string url;
+};
+
+class SetInitialSize final : public TestOperation {
+public:
+    SetInitialSize(const mbgl::Size& size) : width(size.width), height(size.height) {}
+
+    void serialize(Writer& writer) const override {
+        writer.Key("width");
+        writer.Int(width);
+
+        writer.Key("height");
+        writer.Int(height);
+    }
+
+private:
+    uint32_t width;
+    uint32_t height;
+};
+
+TestWriter::TestWriter() = default;
+
+TestWriter::~TestWriter() = default;
+
+TestWriter& TestWriter::withCameraOptions(const mbgl::CameraOptions& camera) {
+    operations.emplace_back(std::make_unique<SetCamera>(camera));
+
+    return *this;
+}
+
+TestWriter& TestWriter::withStyle(const mbgl::style::Style& style) {
+    operations.emplace_back(std::make_unique<SetStyle>(style));
+
+    return *this;
+}
+
+TestWriter& TestWriter::withInitialSize(const mbgl::Size& size) {
+    assert(initialSize == nullptr);
+    initialSize = std::make_unique<SetInitialSize>(size);
+
+    return *this;
+}
+
+bool TestWriter::write(const std::string& dir) const {
+    namespace fs = ghc::filesystem;
+
+    fs::path rootDir(dir);
+    if (!fs::exists(rootDir)) {
+        return false;
+    }
+
+    fs::path testDir;
+    for (int i = 0; i < 1000; ++i) {
+        std::string suffix = std::to_string(i);
+        suffix.insert(suffix.begin(), 3 - suffix.length(), '0');
+
+        testDir = rootDir / suffix;
+        if (!fs::exists(testDir)) {
+            break;
+        }
+    }
+
+    if (!fs::create_directory(testDir)) {
+        return false;
+    }
+
+    fs::path styleFile = testDir / "style.json";
+
+    std::ofstream out;
+    out.open(styleFile.string(), std::ios::out);
+    out << serialize();
+
+    return out.is_open() && out.good();
+}
+
+std::string TestWriter::serialize() const {
+    rapidjson::StringBuffer s;
+    Writer writer(s);
+
+    writer.StartObject();
+
+    writer.Key("version");
+    writer.Int(8);
+
+    writer.Key("metadata");
+    writer.StartObject();
+
+    writer.Key("test");
+    writer.StartObject();
+
+    writer.Key("operations");
+    writer.StartArray();
+
+    for (const auto& operation : operations) {
+        operation->serialize(writer);
+    }
+
+    writer.EndArray();
+
+    if (initialSize) {
+        initialSize->serialize(writer);
+    }
+
+    writer.EndObject();
+    writer.EndObject();
+
+    writer.Key("sources");
+    writer.StartObject();
+    writer.EndObject();
+
+    writer.Key("layers");
+    writer.StartArray();
+    writer.EndArray();
+
+    writer.EndObject();
+
+    return s.GetString();
+}
diff --git a/platform/glfw/test_writer.hpp b/platform/glfw/test_writer.hpp
new file mode 100644
index 0000000000..8e41e3e49a
--- /dev/null
+++ b/platform/glfw/test_writer.hpp
@@ -0,0 +1,29 @@
+#pragma once
+
+#include <mbgl/map/camera.hpp>
+#include <mbgl/style/style.hpp>
+#include <mbgl/util/size.hpp>
+
+#include <memory>
+#include <string>
+#include <vector>
+
+class TestOperation;
+
+class TestWriter final {
+public:
+    TestWriter();
+    ~TestWriter();
+
+    TestWriter& withCameraOptions(const mbgl::CameraOptions&);
+    TestWriter& withStyle(const mbgl::style::Style&);
+    TestWriter& withInitialSize(const mbgl::Size&);
+
+    bool write(const std::string& dir) const;
+
+private:
+    std::string serialize() const;
+
+    std::vector<std::unique_ptr<TestOperation>> operations;
+    std::unique_ptr<TestOperation> initialSize;
+};