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--- devwiki:three_js [2022/06/13 19:15] – [Common Code] ying
+++ devwiki:three_js [2022/07/17 11:49] (current) – [Browse Support] ying
@@ Line 28: / Line 28: @@
       * https://1stwebdesigner.com/examples-of-three-js-in-action/
+====== Browse Support ======
+  * some feature using WebGL 2.0 and some old browser or some mobile browser may not support it,
+  * you can use code to detect webgl2 support and dynamic change the way of coding to support other browser
+    * webgl2 support browser tabel: https://caniuse.com/webgl2
+  * check webgl2 support <code javascript>
+// check webgl2 support for multi sample version
+const gl = document.createElement('canvas').getContext('webgl2');
+if (!gl) {
+  alert('your browser/OS/drivers do not support WebGL2');
+  console.log('your browser/OS/drivers do not support WebGL2');
+} else {
+  console.log('webgl2 works!');
+}
+</code>
 ====== Tools ======
@@ Line 92: / Line 108: @@
 const main_axis = new THREE.AxesHelper()
 scene.add(main_axis)
+</code>
+**Events**
+  * mouse tracking <code javascript>
+//# == add event: mouse position tracking
+let mouse = {
+    x: 0,
+    y: 0
+}
+window.addEventListener('mousemove', (event)=>{
+    //console.log(event.clientX) // from top left corner
+    // top/left to center coordinate
+    mouse.x = (event.clientX / output_size.width)*2-1
+    mouse.y = -(event.clientY / output_size.height)*2+1
+})
+</code>
+  * double click full window <code javascript>
+window.addEventListener('dblclick', ()=>{
+    const full_screen_element = document.fullscreenElement || document.webkitFullscreenElement
+    //output.requestFullScreen()
+    if (!full_screen_element){
+        if (output.requestFullscreen){
+            // normal browse support
+            output.requestFullscreen()
+        } else if (output.webkitRequestFullscreen){
+            // safari
+            output.webkitRequestFullscreen()
+        }
+    }else{
+        if (document.exitFullscreen){
+            // normal browse support
+            document.exitFullscreen()
+        } else if (document.webkitExitFullscreen){
+            // safari
+            document.webkitExitFullscreen()
+        }
+    }
+})
+</code>
+  * simple key down event <code javascript>
+const xSpeed = 0.1;
+const ySpeed = 0.1;
+window.addEventListener("keydown", onDocumentKeyDown, false);
+function onDocumentKeyDown(event) {
+    const keyCode = event.which;
+    console.log(keyCode)
+    if (keyCode == 40) {
+        boat_obj.position.z += ySpeed;
+    } else if (keyCode == 38) {
+        boat_obj.position.z -= ySpeed;
+    } else if (keyCode == 37) {
+        boat_obj.position.x -= xSpeed;
+    } else if (keyCode == 39) {
+        console.log('forward')
+        boat_obj.position.x += xSpeed;
+    }
+    else if (keyCode == 32) {
+        boat_obj.position.set(0, 0, 0);
+    }
+};
+</code>
+  * extra offset key event for tick() <code javascript>
+const offset_step = 0.02
+if ( keyboard.pressed("w") ){
+    main_boat_offset.position.y -= offset_step
+    console.log(main_boat_offset.position.y)
+}
+if ( keyboard.pressed("s") ){
+    main_boat_offset.position.y += offset_step
+    console.log(main_boat_offset.position.y)
+}
+if ( keyboard.pressed("e") ){
+    main_boat_offset.position.z -= offset_step
+    console.log(main_boat_offset.position.z)
+}
+if ( keyboard.pressed("q") ){
+    main_boat_offset.position.z += offset_step
+    console.log(main_boat_offset.position.z)
+}
+if ( keyboard.pressed("d") ){
+    main_boat_offset.position.x -= offset_step
+    console.log(main_boat_offset.position.x)
+}
+if ( keyboard.pressed("a") ){
+    main_boat_offset.position.x += offset_step
+    console.log(main_boat_offset.position.x)
+}
+</code>
+**GUI**
+  * simple gui control <code javascript>
+// -- gui
+const gui = new dat.GUI({ closed:true, width: 300})
+dat.GUI.toggleHide();
+const global_ctrl = {
+    boat: {
+        x: 0,
+        y: 0,
+        z: 0,
+        color:0x00ff00,
+        slide: ()=>{
+            let tl = gsap.timeline();
+            const cur_x = green_box_mesh.position.x
+            tl.to(green_box_mesh.position, {duration: 2, x: cur_x+2})
+            .to(green_box_mesh.position, {duration: 1, x: cur_x})
+        },
+    }
+}
+gui.add(global_ctrl.boat, 'x', -10, 10, 0.1).name('posX').onChange( ()=> {
+    boat_obj.position.x = global_ctrl.boat.x
+} )
+gui.add(global_ctrl.boat, 'y', -10, 10, 0.1).name('posY').onChange( ()=> {
+    boat_obj.position.y = global_ctrl.boat.y
+} )
+gui.add(global_ctrl.boat, 'z', -50, 50, 0.1).name('posZ').onChange( ()=> {
+    boat_obj.position.z = global_ctrl.boat.z
+} )
+gui.addColor(global_ctrl.boat, 'color').onChange(
+    ()=>{
+        green_box_mesh.material.color.set(global_ctrl.green_box.color)
+    }
+)
+gui.add(global_ctrl.boat, 'slide')
+</code>
+**font**
+  * text <code javascript>
+//-- font
+const text_mat = new THREE.MeshMatcapMaterial({matcap:brown_mctex})
+let text_mesh = undefined
+const main_fontLoader = new THREE.FontLoader(load_manager)
+main_fontLoader.load(
+    './font/helvetiker_regular.typeface.json',
+    (result_font)=>{
+        console.log('font loaded')
+        const bevel_a = 0.01 //2
+        const bevel_b = 0.01 //3
+        const text_geo = new THREE.TextBufferGeometry(
+            'Drive Through to Next Scene > ',{
+                font: result_font,
+                size: 0.2,
+                height: .05,
+                curveSegments: 3,
+                // bevelEnabled: true,
+                // bevelThickness: bevel_b,
+                // bevelSize: bevel_a,
+                // bevelOffset: 0,
+                // bevelSegments: 2
+            }
+        )
+        text_geo.computeBoundingBox() // max3, min3
+        text_geo.center()
+        text_mesh = new THREE.Mesh(text_geo, white_2_mat) // text_mat
+        text_mesh.position.y = 1
+        text_mesh.position.x = 123
+        scene.add(text_mesh)
+    }
+)
 </code>
 ====== Three.js Problem and Solution======
@@ Line 159: / Line 345: @@
 child.material.map.inFilter = THREE.NearestFilter
 child.material.map.generateMipmaps = false
+</code>
+  * make object ignore camera frustum culling, so that when camera move closer, object won't disappear <code javascript>
+if(child.name.startsWith("sch_word_")){
+    child.frustumCulled = false
+}
+</code>
+  * video as texture <code javascript>
+// ref: https://stemkoski.github.io/Three.js/
+// https://threejs.org/docs/#api/en/textures/VideoTexture
+// 1. define global variable for controls
+let video = undefined
+let videoImage = undefined
+let videoImageContext = undefined
+let videoTexture = undefined
+let mov_mat = undefined
+// 2. (after all your model loaded event) create video material
+video = document.createElement( 'video' );
+video.src = "video/my_video.mp4";
+video.load();
+// video.play(); // (don't play on start)
+videoImage = document.createElement( 'canvas' );
+videoImage.width = 640;
+videoImage.height = 480;
+videoImageContext = videoImage.getContext( '2d' );
+// background color if no video present
+videoImageContext.fillStyle = '#000000';
+videoImageContext.fillRect( 0, 0, videoImage.width, videoImage.height );
+videoTexture = new THREE.Texture( videoImage );
+videoTexture.minFilter = THREE.LinearFilter;
+videoTexture.magFilter = THREE.LinearFilter;
+mov_mat = new THREE.MeshBasicMaterial( { map: videoTexture, side:THREE.DoubleSide } ); // overdraw: true,
+// 3. assign to geo
+my_video_plane_geo.material = mov_mat;
+// 4. call video_update() during render each frame
+function video_update(){
+    if ( video.readyState === video.HAVE_ENOUGH_DATA )
+    {
+        videoImageContext.drawImage( video, 0, 0 );
+        if ( videoTexture )
+            videoTexture.needsUpdate = true;
+    }
+}
+// 5. support functions for call from other event
+function video_start(){
+    //bgm_sound.pause(); // option to mute bgm sound if you have any
+    video.currentTime = 0;
+    video.play();
+}
+function video_stop(){
+    //bgm_sound.play(); // option to on bgm sound if you have any
+    video.pause();
+    video.currentTime = 0;
+}
+</code>
+  * language based texture switch <code javascript>
+// method 1: (works in firefox, not in chrome)
+if(child.name == "lang_texture_geo") ){
+    lang_texture_geo = child
+    if(main_lang=="cn"){
+        lang_texture_geo.material.map.image.src = "./img/cn_texture.jpg";
+    }
+}
+// method 2: (works in both firefox and chrome)
+const main_texLoader = new THREE.TextureLoader(load_manager)
+const cn_text_ctex = main_texLoader.load("./img/cn_texture.jpg");
+cn_text_ctex.flipY = false;
+if(child.name == "lang_texture_geo") ){
+    lang_texture_geo = child
+    if(main_lang == "cn"){
+        child.material.map = cn_text_ctex;
+    }
+}
 </code>
 ====== Template ======