Added leftToRight option

gsioteam · Feb 13, 2022 · a6e88cc · a6e88cc
1 parent d37a4a1
commit a6e88cc
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Showing 3 changed files with 19 additions and 5 deletions.
diff --git a/example/lib/main.dart b/example/lib/main.dart
@@ -62,6 +62,7 @@ class _MyAppState extends State<MyApp> {
                         child: Text("hello"),
                       ),
                     ),
+                    // leftToRight: true,
                   ),
                   onHorizontalDragStart: (details) {
                     _oldPosition = details.globalPosition;

diff --git a/lib/src/flip_widget.dart b/lib/src/flip_widget.dart
@@ -13,13 +13,15 @@ class FlipWidget extends StatefulWidget {
 
   final Widget? child;
   final Size textureSize;
+  final bool leftToRight;
 
   /// [child] is the widget you want to flip.
   /// [textureSize] is the pixel size of effect layer.
   FlipWidget({
     Key? key,
     this.child,
     this.textureSize = const Size(512, 512),
+    this.leftToRight = false,
   }) : super(key: key);
 
   @override
@@ -80,7 +82,11 @@ class FlipWidgetState extends State<FlipWidget> {
       width: widget.textureSize.width,
       height: widget.textureSize.height,
     );
-    _render = GLRender(widget.textureSize.width.toInt(), widget.textureSize.height.toInt());
+    _render = GLRender(
+      textureWidth: widget.textureSize.width.toInt(),
+      textureHeight: widget.textureSize.height.toInt(),
+      leftToRight: widget.leftToRight,
+    );
     controller.ready.then((value) {
       _render.initialize();
     });

diff --git a/lib/src/gl_render.dart b/lib/src/gl_render.dart
@@ -35,13 +35,13 @@ float py(float uvy) {
 }
 
 vec2 to_uv(vec2 pos) {
-    return vec2(pos.x / size.x, 1.0 - pos.y / size.y);
+    return vec2({l2r} pos.x / size.x, 1.0 - pos.y / size.y);
 }
 
 void main()
 {
     const float roll_size = 6.0;
-    float x1 = px(uv.x);
+    float x1 = px({l2r} uv.x);
     float y1 = py(1.0 - uv.y);
     float per = px(percent);
     if (y1 / tilt + per < x1) {
@@ -171,7 +171,9 @@ class GLRender {
   void initialize() {
     _templateString = malloc.allocate(sizeOf<Int8>() * 512);
 
-    _programHandle = loadProgram(_VertexShader, _FragmentShader);
+    _programHandle = loadProgram(_VertexShader, _FragmentShader.replaceAll(
+      "{l2r}", leftToRight ? "1.0 - " : ""
+    ));
 
     Pointer<Int32> ret = malloc.allocate(sizeOf<Int32>());
     GLES20.glGetProgramiv(_programHandle, GL_LINK_STATUS, ret);
@@ -263,6 +265,7 @@ class GLRender {
 
   int textureWidth;
   int textureHeight;
+  bool leftToRight;
 
   void draw(double percent, double tilt) {
 
@@ -309,5 +312,9 @@ class GLRender {
     GLES20.glDeleteProgram(_programHandle);
   }
 
-  GLRender(this.textureWidth, this.textureHeight);
+  GLRender({
+    required this.textureWidth,
+    required this.textureHeight,
+    required this.leftToRight,
+  });
 }