From 84f3ce50fcf2a16fd0feea4a6b6c2bcc04da08a8 Mon Sep 17 00:00:00 2001
From: lvpengwei <pengwei.lv@gmail.com>
Date: Thu, 2 Nov 2023 08:26:29 -0500
Subject: [PATCH] Add web demo. (#21)

---
 web/demo/TGFXDemoBindings.cpp | 118 ++++++++++++++++++++++++++++++++++
 web/demo/index.ts             |   7 ++
 web/script/build.sh           |   5 ++
 3 files changed, 130 insertions(+)
 create mode 100644 web/demo/TGFXDemoBindings.cpp

diff --git a/web/demo/TGFXDemoBindings.cpp b/web/demo/TGFXDemoBindings.cpp
new file mode 100644
index 00000000..cc0f1539
--- /dev/null
+++ b/web/demo/TGFXDemoBindings.cpp
@@ -0,0 +1,118 @@
+/////////////////////////////////////////////////////////////////////////////////////////////////
+//
+//  Tencent is pleased to support the open source community by making tgfx available.
+//
+//  Copyright (C) 2023 THL A29 Limited, a Tencent company. All rights reserved.
+//
+//  Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
+//  in compliance with the License. You may obtain a copy of the License at
+//
+//      https://opensource.org/licenses/BSD-3-Clause
+//
+//  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 <emscripten/bind.h>
+#include "tgfx/opengl/webgl/WebGLWindow.h"
+
+using namespace emscripten;
+using namespace tgfx;
+
+class TGFXView {
+ public:
+  explicit TGFXView(std::string canvasID) : canvasID(std::move(canvasID)) {
+    updateSize();
+  }
+
+  void updateSize() {
+    if (!canvasID.empty()) {
+      emscripten_get_canvas_element_size(canvasID.c_str(), &_width, &_height);
+      surface = nullptr;
+    }
+  }
+
+  void draw() {
+    if (surface == nullptr) {
+      createSurface();
+    }
+    if (surface == nullptr) {
+      return;
+    }
+    auto device = window->getDevice();
+    auto context = device->lockContext();
+    if (context == nullptr) {
+      return;
+    }
+    auto canvas = surface->getCanvas();
+    canvas->clear();
+    tgfx::Paint paint;
+    paint.setColor(tgfx::Color{0.0f, 0.8f, 0.0f, 1.f});
+    if (drawCount % 2 == 0) {
+      auto rect = tgfx::Rect::MakeXYWH(20, 20, 100, 100);
+      canvas->drawRect(rect, paint);
+    } else {
+      int tileSize = 8;
+      for (int y = 0; y < _height; y += tileSize) {
+        bool draw = (y / tileSize) % 2 == 1;
+        for (int x = 0; x < _width; x += tileSize) {
+          if (draw) {
+            auto rect =
+                tgfx::Rect::MakeXYWH(static_cast<float>(x), static_cast<float>(y),
+                                     static_cast<float>(tileSize), static_cast<float>(tileSize));
+            canvas->drawRect(rect, paint);
+          }
+          draw = !draw;
+        }
+      }
+    }
+    surface->flush();
+    context->submit();
+    window->present(context);
+    device->unlock();
+    drawCount++;
+  }
+
+ private:
+  void createSurface() {
+    if (_width <= 0 || _height <= 0) {
+      return;
+    }
+    if (window == nullptr) {
+      window = WebGLWindow::MakeFrom(canvasID);
+    }
+    if (window == nullptr) {
+      return;
+    }
+    auto device = window->getDevice();
+    auto context = device->lockContext();
+    if (context == nullptr) {
+      return;
+    }
+    surface = window->createSurface(context);
+    device->unlock();
+  }
+
+  std::string canvasID;
+  std::shared_ptr<tgfx::Window> window;
+  std::shared_ptr<tgfx::Surface> surface;
+  int _width = 0;
+  int _height = 0;
+  int drawCount = 0;
+};
+
+EMSCRIPTEN_BINDINGS(TGFXDemo) {
+  class_<TGFXView>("TGFXView")
+      .smart_ptr<std::shared_ptr<TGFXView>>("TGFXView")
+      .class_function("_Make", optional_override([](const std::string& canvasID) {
+                        if (canvasID.empty()) {
+                          return std::shared_ptr<TGFXView>(nullptr);
+                        }
+                        return std::make_shared<TGFXView>(canvasID);
+                      }))
+      .function("updateSize", &TGFXView::updateSize)
+      .function("draw", &TGFXView::draw);
+}
diff --git a/web/demo/index.ts b/web/demo/index.ts
index 6d80c02e..275ac054 100644
--- a/web/demo/index.ts
+++ b/web/demo/index.ts
@@ -9,4 +9,11 @@ window.onload = async () => {
   document.getElementById('container')!.style.display = 'block';
   TGFXModule.ScalerContext.isEmoji('测试');
   TGFXModule.ScalerContext.isEmoji('👍');
+  if (TGFXModule.TGFXView) {
+    const view = TGFXModule.TGFXView._Make('#tgfx');
+    document.getElementById('tgfx')!.onclick = () => {
+      view.draw();
+    };
+    view.draw();
+  }
 };
diff --git a/web/script/build.sh b/web/script/build.sh
index 898d7ee6..1158b7cb 100755
--- a/web/script/build.sh
+++ b/web/script/build.sh
@@ -21,6 +21,10 @@ emcmake cmake -S $SOURCE_DIR -B $BUILD_DIR -G Ninja -DCMAKE_BUILD_TYPE="$CMAKE_B
 
 cmake --build $BUILD_DIR --target tgfx
 
+if [[ $@ == *demo* ]]; then
+  DEMO_FILE=$SOURCE_DIR/web/demo/TGFXDemoBindings.cpp
+fi
+
 emcc $RELEASE_CONF -std=c++17 \
   -I$SOURCE_DIR/include/ \
   -I$SOURCE_DIR/src/ \
@@ -39,6 +43,7 @@ emcc $RELEASE_CONF -std=c++17 \
   -s ENVIRONMENT="web,worker" \
   -s EXPORT_ES6=1 \
   -s USE_ES6_IMPORT_META=0 \
+  $DEMO_FILE \
   -o ../src/wasm/tgfx.js
 
 if test $? -eq 0; then