Wasm: allow iterator and add functions for layers revising (#730)

* common: move iterator functionality into separate IteratorModule
* wasm: allow internal lib dependencies and iterator
* wasm: added functions for layers revising

This patch adds functions to thorvgwasm.cpp:
 layers() - that return a list of paints in a picture
 bounds() - that returns a bounds of a given paint
 setOpacity() - that sets the opacity of a given paint

inc/thorvg.h

@@ -50,7 +50,7 @@ protected: \
     friend Canvas; \
     friend Scene; \
     friend Picture; \
-    friend SaveModule; \
+    friend IteratorModule; \
 
 
 #define _TVG_DECALRE_IDENTIFIER() \
@@ -62,6 +62,7 @@ namespace tvg
 {
 
 class RenderMethod;
+class IteratorModule;
 class SaveModule;
 class Scene;
 class Picture;

src/lib/meson.build

@@ -19,6 +19,7 @@ source_file = [
    'tvgLzw.h',
    'tvgPictureImpl.h',
    'tvgRender.h',
+   'tvgIteratorModule.h',
    'tvgSaveModule.h',
    'tvgSceneImpl.h',
    'tvgShapeImpl.h',

src/lib/tvgIteratorModule.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2021 Samsung Electronics Co., Ltd. All rights reserved.
+
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef _TVG_ITERATOR_MODULE_H_
+#define _TVG_ITERATOR_MODULE_H_
+
+#include "tvgPaint.h"
+
+namespace tvg
+{
+
+class IteratorModule
+{
+public:
+    //Utility Method: Iterator Delegator
+    Iterator* iterator(const Paint* paint)
+    {
+        return paint->pImpl->iterator();
+    }
+};
+
+}
+
+#endif //_TVG_ITERATOR_MODULE_H_

src/lib/tvgSaveModule.h

@@ -22,26 +22,20 @@
 #ifndef _TVG_SAVE_MODULE_H_
 #define _TVG_SAVE_MODULE_H_
 
-#include "tvgPaint.h"
+#include "tvgIteratorModule.h"
 
 namespace tvg
 {
 
-class SaveModule
+class SaveModule : public IteratorModule
 {
 public:
     virtual ~SaveModule() {}
 
     virtual bool save(Paint* paint, const string& path, bool compress) = 0;
     virtual bool close() = 0;
-
-    //Utility Method: Iterator Delegator
-    Iterator* iterator(const Paint* paint)
-    {
-        return paint->pImpl->iterator();
-    }
 };
 
 }
 
-#endif //_TVG_SAVE_MODULE_H_
+#endif //_TVG_SAVE_MODULE_H_

src/meson.build

@@ -40,12 +40,12 @@ thorvg_dep = declare_dependency(
 )
 
 if (cc.get_id() == 'emscripten')
-
   subdir('wasm')
 
   executable('thorvg-wasm',
-              [],
-              dependencies : [thorvg_dep, thorvg_wasm_dep],
+             [],
+             include_directories : headers,
+             dependencies : [thorvg_lib_dep, thorvg_wasm_dep],
             )
 endif
 

src/wasm/thorvgwasm.cpp

@@ -21,6 +21,7 @@
  */
 
 #include <thorvg.h>
+#include "tvgIteratorModule.h"
 
 #include <emscripten/bind.h>
 
@@ -30,7 +31,7 @@ using namespace tvg;
 
 string defaultData("<svg height=\"1000\" viewBox=\"0 0 1000 1000\" width=\"1000\" xmlns=\"http://www.w3.org/2000/svg\"><path d=\"M.10681413.09784845 1000.0527.01592069V1000.0851L.06005738 999.9983Z\" fill=\"#09bbf1\" stroke-width=\"3.910218\"/><g fill=\"#252f35\"><g stroke-width=\"3.864492\"><path d=\"M256.61221 100.51736H752.8963V386.99554H256.61221Z\"/><path d=\"M201.875 100.51736H238.366478V386.99554H201.875Z\"/><path d=\"M771.14203 100.51736H807.633508V386.99554H771.14203Z\"/></g><path d=\"M420.82388 380H588.68467V422.805317H420.82388Z\" stroke-width=\"3.227\"/><path d=\"m420.82403 440.7101v63.94623l167.86079 25.5782V440.7101Z\"/><path d=\"M420.82403 523.07258V673.47362L588.68482 612.59701V548.13942Z\"/></g><g fill=\"#222f35\"><path d=\"M420.82403 691.37851 588.68482 630.5019 589 834H421Z\"/><path d=\"m420.82403 852.52249h167.86079v28.64782H420.82403v-28.64782 0 0\"/><path d=\"m439.06977 879.17031c0 0-14.90282 8.49429-18.24574 15.8161-4.3792 9.59153 0 31.63185 0 31.63185h167.86079c0 0 4.3792-22.04032 0-31.63185-3.34292-7.32181-18.24574-15.8161-18.24574-15.8161z\"/></g><g fill=\"#09bbf1\"><path d=\"m280 140h15v55l8 10 8-10v-55h15v60l-23 25-23-25z\"/><path d=\"m335 140v80h45v-50h-25v10h10v30h-15v-57h18v-13z\"/></g></svg>");
 
-class __attribute__((visibility("default"))) ThorvgWasm
+class __attribute__((visibility("default"))) ThorvgWasm : public IteratorModule
 {
 public:
     static unique_ptr<ThorvgWasm> create()
@@ -157,6 +158,47 @@ public:
         return true;
     }
 
+    val layers()
+    {
+        //returns an array of a structure Layer: [id] [depth] [type] [composite]
+        mLayers.reset();
+        sublayers(&mLayers, mPicture, 0);
+
+        return val(typed_memory_view(mLayers.count * sizeof(Layer) / sizeof(uint32_t), (uint32_t *)(mLayers.data)));
+    }
+
+    bool setOpacity(uint32_t paintId, uint8_t opacity)
+    {
+        const Paint* paint = findPaintById(mPicture, paintId, nullptr);
+        if (!paint) return false;
+        const_cast<Paint*>(paint)->opacity(opacity);
+        return true;
+    }
+
+    val bounds(uint32_t paintId)
+    {
+        Array<const Paint *> parents;
+        const Paint* paint = findPaintById(mPicture, paintId, &parents);
+        if (!paint) return val(typed_memory_view<float>(0, nullptr));
+        paint->bounds(&mBounds[0], &mBounds[1], &mBounds[2], &mBounds[3]);
+
+        mBounds[2] += mBounds[0];
+        mBounds[3] += mBounds[1];
+
+        for (auto paint = parents.data; paint < (parents.data + parents.count); ++paint) {
+           auto m = const_cast<Paint*>(*paint)->transform();
+           mBounds[0] = mBounds[0] * m.e11 + m.e13;
+           mBounds[1] = mBounds[1] * m.e22 + m.e23;
+           mBounds[2] = mBounds[2] * m.e11 + m.e13;
+           mBounds[3] = mBounds[3] * m.e22 + m.e23;
+        }
+
+        mBounds[2] -= mBounds[0];
+        mBounds[3] -= mBounds[1];
+
+        return val(typed_memory_view(4, mBounds));
+    }
+
 private:
     explicit ThorvgWasm()
     {
@@ -183,6 +225,69 @@ private:
         if (mPicture) mPicture->size(width, height);
     }
 
+    struct Layer
+    {
+        uint32_t paint; //cast of a paint pointer
+        uint32_t depth;
+        uint32_t type;
+        uint32_t composite;
+    };
+    void sublayers(Array<Layer>* layers, const Paint* paint, uint32_t depth)
+    {
+        //paint
+        if (paint->id() != TVG_CLASS_ID_SHAPE) {
+            auto it = this->iterator(paint);
+            if (it->count() > 0) {
+                layers->reserve(layers->count + it->count());
+                it->begin();
+                while (auto child = it->next()) {
+                    uint32_t type = child->id();
+                    layers->push({.paint = reinterpret_cast<uint32_t>(child), .depth = depth + 1, .type = type, .composite = static_cast<uint32_t>(CompositeMethod::None)});
+                    sublayers(layers, child, depth + 1);
+                }
+            }
+        }
+        //composite
+        const Paint* compositeTarget = nullptr;
+        CompositeMethod composite = paint->composite(&compositeTarget);
+        if (compositeTarget && composite != CompositeMethod::None) {
+            uint32_t type = compositeTarget->id();
+            layers->push({.paint = reinterpret_cast<uint32_t>(compositeTarget), .depth = depth, .type = type, .composite = static_cast<uint32_t>(composite)});
+            sublayers(layers, compositeTarget, depth);
+        }
+    }
+
+    const Paint* findPaintById(const Paint* parent, uint32_t paintId, Array<const Paint *>* parents) {
+        //validate paintId is correct and exists in the picture
+        if (reinterpret_cast<uint32_t>(parent) == paintId) {
+            if (parents) parents->push(parent);
+            return parent;
+        }
+        //paint
+        if (parent->id() != TVG_CLASS_ID_SHAPE) {
+            auto it = this->iterator(parent);
+            if (it->count() > 0) {
+                it->begin();
+                while (auto child = it->next()) {
+                    if (auto paint = findPaintById(child, paintId, parents)) {
+                        if (parents) parents->push(parent);
+                        return paint;
+                    }
+                }
+            }
+        }
+        //composite
+        const Paint* compositeTarget = nullptr;
+        CompositeMethod composite = parent->composite(&compositeTarget);
+        if (compositeTarget && composite != CompositeMethod::None) {
+            if (auto paint = findPaintById(compositeTarget, paintId, parents)) {
+                if (parents) parents->push(parent);
+                return paint;
+            }
+        }
+        return nullptr;
+    }
+
 private:
     string                 mErrorMsg;
     unique_ptr< SwCanvas > mSwCanvas = nullptr;
@@ -191,6 +296,9 @@ private:
 
     uint32_t               mWidth{0};
     uint32_t               mHeight{0};
+
+    Array<Layer>           mLayers;
+    float                  mBounds[4];
     float                  mOriginalSize[2];
 };
 
@@ -205,5 +313,9 @@ EMSCRIPTEN_BINDINGS(thorvg_bindings) {
     .function("render", &ThorvgWasm::render)
     .function("originalSize", &ThorvgWasm::originalSize)
 
-    .function("saveTvg", &ThorvgWasm::saveTvg);
+    .function("saveTvg", &ThorvgWasm::saveTvg)
+
+    .function("layers", &ThorvgWasm::layers)
+    .function("bounds", &ThorvgWasm::bounds)
+    .function("setOpacity", &ThorvgWasm::setOpacity);
 }