[Qt] Make it possible to disable libwebp and libjpeg-turbo at build time

Pull less dependencies.

platform/qt/platform.gyp

@@ -39,7 +39,6 @@
       'sources': [
         '../default/asset_file_source.cpp',
         '../default/default_file_source.cpp',
-        '../default/jpeg_reader.cpp',
         '../default/log_stderr.cpp',
         '../default/mbgl/storage/offline.cpp',
         '../default/mbgl/storage/offline_database.cpp',
@@ -48,7 +47,6 @@
         '../default/sqlite3.cpp',
         '../default/string_stdlib.cpp',
         '../default/thread.cpp',
-        '../default/webp_reader.cpp',
         'include/qmapbox.hpp',
         'include/qmapboxgl.hpp',
         'include/qquickmapboxgl.hpp',
@@ -75,7 +73,6 @@
       'variables': {
         'cflags': [
           '<@(boost_cflags)',
-          '<@(libjpeg-turbo_cflags)',
           '<@(nunicode_cflags)',
           '<@(opengl_cflags)',
           '<@(qt_core_cflags)',
@@ -83,25 +80,20 @@
           '<@(qt_network_cflags)',
           '<@(rapidjson_cflags)',
           '<@(sqlite_cflags)',
-          '<@(webp_cflags)',
           '-fPIC',
         ],
         'ldflags': [
-          '<@(libjpeg-turbo_ldflags)',
           '<@(nunicode_ldflags)',
           '<@(opengl_ldflags)',
           '<@(qt_core_ldflags)',
           '<@(qt_gui_ldflags)',
           '<@(qt_network_ldflags)',
           '<@(sqlite_ldflags)',
-          '<@(webp_ldflags)',
           '<@(zlib_ldflags)',
         ],
         'libraries': [
           '<@(nunicode_static_libs)',
           '<@(sqlite_static_libs)',
-          '<@(libjpeg-turbo_static_libs)',
-          '<@(webp_static_libs)',
           '<@(zlib_static_libs)',
         ],
       },
@@ -114,6 +106,26 @@
       ],
 
       'conditions': [
+        ['<(qt_image_decoders) == 0', {
+          'sources': [
+            '../default/jpeg_reader.cpp',
+            '../default/webp_reader.cpp',
+          ],
+          'variables': {
+            'cflags': [
+              '<@(libjpeg-turbo_cflags)',
+              '<@(webp_cflags)',
+            ],
+            'ldflags': [
+              '<@(libjpeg-turbo_ldflags)',
+              '<@(webp_ldflags)',
+            ],
+            'libraries': [
+              '<@(libjpeg-turbo_static_libs)',
+              '<@(webp_static_libs)',
+            ],
+          },
+        }],
         ['<(qt_version_major) == 4', {
           'variables': {
             'cflags': [

platform/qt/scripts/configure.sh

@@ -35,6 +35,7 @@ function print_qt_flags {
 
     QT_VERSION_MAJOR=$(qmake -query QT_VERSION | cut -d. -f1)
     CONFIG+="    'qt_version_major%': ['${QT_VERSION_MAJOR}'],"$LN
+    CONFIG+="    'qt_image_decoders%': [0],"$LN
 
     CONFIG+="    'qt_core_cflags%': $(quote_flags $(mason cflags Qt system "QtCore")),"$LN
     CONFIG+="    'qt_gui_cflags%': $(quote_flags $(mason cflags Qt system "QtGui")),"$LN

platform/qt/src/image.cpp

@@ -19,14 +19,16 @@ std::string encodePNG(const PremultipliedImage& pre) {
     return std::string(array.constData(), array.size());
 }
 
+#if !defined(QT_IMAGE_DECODERS)
 PremultipliedImage decodeJPEG(const uint8_t*, size_t);
 PremultipliedImage decodeWebP(const uint8_t*, size_t);
+#endif
 
 PremultipliedImage decodeImage(const std::string& string) {
     const uint8_t* data = reinterpret_cast<const uint8_t*>(string.data());
     const size_t size = string.size();
 
-    // FIXME: Use Qt WebP decoder plugin.
+#if !defined(QT_IMAGE_DECODERS)
     if (size >= 12) {
         uint32_t riff_magic = (data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3];
         uint32_t webp_magic = (data[8] << 24) | (data[9] << 16) | (data[10] << 8) | data[11];
@@ -35,13 +37,13 @@ PremultipliedImage decodeImage(const std::string& string) {
         }
     }
 
-    // Use libjpeg-turbo rather than the built-in version of libjpeg.
     if (size >= 2) {
         uint16_t magic = ((data[0] << 8) | data[1]) & 0xffff;
         if (magic == 0xFFD8) {
             return decodeJPEG(data, size);
         }
     }
+#endif
 
     QImage image =
         QImage::fromData(data, size)

src/mbgl/util/mapbox.cpp

@@ -153,12 +153,12 @@ std::string canonicalizeTileURL(const std::string& url, SourceType type, uint16_
     auto tileset = url.substr(tilesetStartIdx, tilesetEndIdx - tilesetStartIdx);
     auto extension = url.substr(extensionIdx + 1, queryIdx - extensionIdx - 1);
 
-#if !defined(__ANDROID__) && !defined(__APPLE__)
+#if !defined(__ANDROID__) && !defined(__APPLE__) && !defined(QT_IMAGE_DECODERS)
     // Replace PNG with WebP.
     if (extension == "png") {
         extension = "webp";
     }
-#endif // !defined(__ANDROID__) && !defined(__APPLE__)
+#endif // !defined(__ANDROID__) && !defined(__APPLE__) && !defined(QT_IMAGE_DECODERS)
 
     std::string result = "mapbox://tiles/" + tileset + "/{z}/{x}/{y}";
 

test/util/image.cpp

@@ -78,13 +78,13 @@ TEST(Image, JPEGTile) {
     EXPECT_EQ(256, image.height);
 }
 
-#if !defined(__ANDROID__) && !defined(__APPLE__)
+#if !defined(__ANDROID__) && !defined(__APPLE__) && !defined(QT_IMAGE_DECODERS)
 TEST(Image, WebPTile) {
     PremultipliedImage image = decodeImage(util::read_file("test/fixtures/image/tile.webp"));
     EXPECT_EQ(256, image.width);
     EXPECT_EQ(256, image.height);
 }
-#endif // !defined(__ANDROID__) && !defined(__APPLE__)
+#endif // !defined(__ANDROID__) && !defined(__APPLE__) && !defined(QT_IMAGE_DECODERS)
 
 TEST(Image, Premultiply) {
     UnassociatedImage rgba { 1, 1 };