better example and bugfix

Examples/Video/index.ios.js

@@ -3,6 +3,7 @@ const {
   AppRegistry,
   StyleSheet,
   View,
+  Text,
 } = React;
 const Video = require("react-native-video").default;
 const {
@@ -37,20 +38,32 @@ class App extends React.Component {
     this.state = {
       blur: 0,
       blurPasses: 2,
-      hue: 0
+      hue: 0,
+      mode: 0
     };
   }
   render () {
-    const { blur, hue, blurPasses } = this.state;
+    const { blur, hue, blurPasses, mode } = this.state;
     return (
       <View style={styles.container}>
-        <Surface autoRedraw eventsThrough width={width} height={height}>
+        <Surface pixelRatio={1} width={640} height={480} autoRedraw eventsThrough width={width} height={height}>
           <Blur passes={blurPasses} factor={blur}>
             <HueRotate hue={hue}>
-              <Video source={{ uri: "video" }} repeat style={styles.video} />
+              { mode === 0 ?
+                <Video source={{ uri: "video" }} repeat style={styles.video} /> :
+                mode === 1 ?
+                <View style={{ flex: 1, backgroundColor: "#fff", padding: 10 }}>
+                  <Text style={{ fontSize: 80, color: "#F00" }}>Hello</Text>
+                  <Text style={{ fontSize: 60, color: "#00F" }}>World</Text>
+                </View> :
+                mode === 2 ?
+                "http://i.imgur.com/2Go2D7i.jpg"
+                : null
+              }
             </HueRotate>
           </Blur>
         </Surface>
+        <Field min={0} max={3} step={1} value={mode} onChange={mode => this.setState({ mode })} name="Content" width={width} />
         <Field min={0} max={2*Math.PI} value={hue} onChange={hue => this.setState({ hue })} name="Hue" width={width} />
         <Field min={0} max={16} value={blur} onChange={blur => this.setState({ blur })} name="Blur" width={width} />
         <Field min={2} max={8} step={1} value={blurPasses} onChange={blurPasses => this.setState({ blurPasses })} name="Blur Passes" width={width} />

ios/GLCanvas.m

@@ -342,7 +342,7 @@ RCT_NOT_IMPLEMENTED(-init)
         imgData = [GLImageData genPixelsWithView:v withPixelRatio:self.contentScaleFactor];
       }
     }
-    if (imgData) rasterizedContent[i] = imgData;
+    rasterizedContent[i] = imgData==nil ? [GLImageData empty] : imgData;
   }
   _rasterizedContent = rasterizedContent;
   [self setNeedsDisplay];

ios/GLShader.m

@@ -384,7 +384,7 @@ GLuint compileShader (NSString* shaderName, NSString* shaderString, GLenum shade
 
   [self computeMeta];
 
-  pointerLoc = glGetAttribLocation(program, "position");
+  pointerLoc = glGetAttribLocation(program, "_p");
 
   glGenBuffers(1, &buffer);
   glBindBuffer(GL_ARRAY_BUFFER, buffer);

ios/RNGLContext.m

@@ -77,7 +77,7 @@ withOnCompile:(RCTResponseSenderBlock)onCompile
   _shaders[id] = shader;
 }
 
-static NSString* fullViewportVert = @"attribute vec2 position;varying vec2 uv;void main() {gl_Position = vec4(position,0.0,1.0);uv = vec2(0.5, 0.5) * (position+vec2(1.0, 1.0));}";
+static NSString* fullViewportVert = @"attribute vec2 _p;varying vec2 uv;void main(){gl_Position = vec4(_p,0.,1.);uv=vec2(.5,.5)*(_p+vec2(1.,1.));}";
 
 NSString* glTypeString (int type) {
   switch (type) {