src/com/android/musicvis/vis5/Visualization5RS.java

/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.musicvis.vis5;

import static android.renderscript.ProgramFragment.EnvMode.REPLACE;
import static android.renderscript.Sampler.Value.LINEAR;
import static android.renderscript.Sampler.Value.WRAP;

import com.android.musicvis.R;
import com.android.musicvis.RenderScriptScene;

import android.media.MediaPlayer;
import android.os.Handler;
import android.renderscript.Allocation;
import android.renderscript.Element;
import android.renderscript.Primitive;
import android.renderscript.ProgramFragment;
import android.renderscript.ProgramStore;
import android.renderscript.ProgramVertex;
import android.renderscript.Sampler;
import android.renderscript.ScriptC;
import android.renderscript.SimpleMesh;
import android.renderscript.Type;
import android.renderscript.Element.Builder;
import android.renderscript.ProgramStore.BlendDstFunc;
import android.renderscript.ProgramStore.BlendSrcFunc;
import android.util.Log;
import android.view.MotionEvent;

import java.util.TimeZone;

class Visualization5RS extends RenderScriptScene {

    private final Handler mHandler = new Handler();
    private final Runnable mDrawCube = new Runnable() {
        public void run() {
            updateWave();
        }
    };
    private boolean mVisible;

    private int mNeedlePos = 0;
    private int mNeedleSpeed = 0;
    // tweak this to get quicker/slower response
    private int mNeedleMass = 10;
    private int mSpringForceAtOrigin = 200;
    
    static class WorldState {
        public float mAngle;
        public int   mPeak;
        public float mRotate;
        public float mTilt;
        public int   mIdle;
        public int   mWaveCounter;
    }
    WorldState mWorldState = new WorldState();
    private Type mStateType;
    private Allocation mState;

    private ProgramStore mPfsBackground;
    private ProgramFragment mPfBackground;
    private Sampler mSampler;
    private Allocation[] mTextures;
    
    private ProgramVertex mPVBackground;
    private ProgramVertex.MatrixAllocation mPVAlloc;

    private SimpleMesh mCubeMesh;

    protected Allocation mPointAlloc;
    // 256 lines, with 4 points per line (2 space, 2 texture) each consisting of x and y,
    // so 8 floats per line.
    protected float [] mPointData = new float[256*8];

    private Allocation mLineIdxAlloc;
    // 2 indices per line
    private short [] mIndexData = new short[256*2];
    
    private short [] mVizData = new short[1024];

    private static final int RSID_STATE = 0;
    private static final int RSID_POINTS = 1;
    private static final int RSID_LINES = 2;
    private static final int RSID_PROGRAMVERTEX = 3;

    private float mTouchY;
    
    Visualization5RS(int width, int height) {
        super(width, height);
        mWidth = width;
        mHeight = height;
        // the x, s and t coordinates don't change, so set those now
        int outlen = mPointData.length / 8;
        int half = outlen / 2;
        for(int i = 0; i < outlen; i++) {
            mPointData[i*8]   = i - half;          // start point X (Y set later)
            mPointData[i*8+2] = 0;                 // start point S
            mPointData[i*8+3] = 0;                 // start point T
            mPointData[i*8+4] = i - half;          // end point X (Y set later)
            mPointData[i*8+6] = 1.0f;              // end point S
            mPointData[i*8+7] = 0f;                // end point T
        }
    }

    @Override
    public void resize(int width, int height) {
        super.resize(width, height);
        if (mPVAlloc != null) {
            mPVAlloc.setupProjectionNormalized(width, height);
        }
        mWorldState.mTilt = -20;
    }

    @Override
    public void onTouchEvent(MotionEvent event) {
        switch(event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                mTouchY = event.getY();
                break;
            case MotionEvent.ACTION_MOVE:
                float dy = event.getY() - mTouchY;
                mTouchY += dy;
                dy /= 10;
                dy += mWorldState.mTilt;
                if (dy > 0) {
                    dy = 0;
                } else if (dy < -45) {
                    dy = -45;
                }
                mWorldState.mTilt = dy;
                mState.data(mWorldState);
        }
    }
    
    @Override
    public void setOffset(float xOffset, float yOffset, int xPixels, int yPixels) {
        // update our state, then push it to the renderscript
        mWorldState.mRotate = (xOffset - 0.5f) * 90;
        mState.data(mWorldState);
    }

    @Override
    protected ScriptC createScript() {

        // Create a renderscript type from a java class. The specified name doesn't
        // really matter; the name by which we refer to the object in RenderScript
        // will be specified later.
        mStateType = Type.createFromClass(mRS, WorldState.class, 1, "WorldState");
        // Create an allocation from the type we just created.
        mState = Allocation.createTyped(mRS, mStateType);

        // First set up the coordinate system and such
        ProgramVertex.Builder pvb = new ProgramVertex.Builder(mRS, null, null);
        mPVBackground = pvb.create();
        mPVBackground.setName("PVBackground");
        mPVAlloc = new ProgramVertex.MatrixAllocation(mRS);
        mPVBackground.bindAllocation(mPVAlloc);
        mPVAlloc.setupProjectionNormalized(mWidth, mHeight);

        mTextures = new Allocation[8];
        mTextures[0] = Allocation.createFromBitmapResourceBoxed(mRS, mResources, R.drawable.background, Element.RGBA_8888(mRS), false);
        mTextures[0].setName("Tvumeter_background");
        mTextures[1] = Allocation.createFromBitmapResourceBoxed(mRS, mResources, R.drawable.frame, Element.RGBA_8888(mRS), false);
        mTextures[1].setName("Tvumeter_frame");
        mTextures[2] = Allocation.createFromBitmapResourceBoxed(mRS, mResources, R.drawable.peak_on, Element.RGBA_8888(mRS), false);
        mTextures[2].setName("Tvumeter_peak_on");
        mTextures[3] = Allocation.createFromBitmapResourceBoxed(mRS, mResources, R.drawable.peak_off, Element.RGBA_8888(mRS), false);
        mTextures[3].setName("Tvumeter_peak_off");
        mTextures[4] = Allocation.createFromBitmapResourceBoxed(mRS, mResources, R.drawable.needle, Element.RGBA_8888(mRS), false);
        mTextures[4].setName("Tvumeter_needle");
        mTextures[5] = Allocation.createFromBitmapResourceBoxed(mRS, mResources, R.drawable.black, Element.RGB_565(mRS), false);
        mTextures[5].setName("Tvumeter_black");
        mTextures[6] = Allocation.createFromBitmapResource(mRS, mResources, R.drawable.albumart, Element.RGBA_8888(mRS), false);
        mTextures[6].setName("Tvumeter_album");
        mTextures[7] = Allocation.createFromBitmapResource(mRS, mResources, R.drawable.fire, Element.RGB_565(mRS), false);
        mTextures[7].setName("Tlinetexture");

        final int count = mTextures.length;
        for (int i = 0; i < count; i++) {
            mTextures[i].uploadToTexture(0);
        }
        
        Sampler.Builder samplerBuilder = new Sampler.Builder(mRS);
        samplerBuilder.setMin(LINEAR);
        samplerBuilder.setMag(LINEAR);
        samplerBuilder.setWrapS(WRAP);
        samplerBuilder.setWrapT(WRAP);
        mSampler = samplerBuilder.create();

        {
            ProgramFragment.Builder builder = new ProgramFragment.Builder(mRS, null, null);
            builder.setTexEnable(true, 0);
            builder.setTexEnvMode(REPLACE, 0);
            mPfBackground = builder.create();
            mPfBackground.setName("PFBackground");
            mPfBackground.bindSampler(mSampler, 0);
        }

        {
            ProgramStore.Builder builder = new ProgramStore.Builder(mRS, null, null);
            builder.setDepthFunc(ProgramStore.DepthFunc.EQUAL);
            //builder.setBlendFunc(BlendSrcFunc.SRC_ALPHA, BlendDstFunc.ONE_MINUS_SRC_ALPHA);
            builder.setBlendFunc(BlendSrcFunc.ONE, BlendDstFunc.ONE_MINUS_SRC_ALPHA);
            builder.setDitherEnable(true); // without dithering there is severe banding
            builder.setDepthMask(false);
            mPfsBackground = builder.create();
            mPfsBackground.setName("PFSBackground");
        }
        
        // Start creating the mesh
        final SimpleMesh.Builder meshBuilder = new SimpleMesh.Builder(mRS);

        // Create the Element for the points
        Builder elementBuilder = new Builder(mRS);
        // By specifying a prefix, even an empty one, the members will be accessible
        // in the renderscript. If we just called addFloatXYZ(), the members would be
        // unnamed in the renderscript struct definition.
        elementBuilder.addFloatXY("");
        elementBuilder.addFloatST("");
        final Element vertexElement = elementBuilder.create();
        final int vertexSlot = meshBuilder.addVertexType(vertexElement, mPointData.length / 4);
        // Specify the type and number of indices we need. We'll allocate them later.
        meshBuilder.setIndexType(Element.INDEX_16(mRS), mIndexData.length);
        // This will be a line mesh
        meshBuilder.setPrimitive(Primitive.LINE);

        // Create the Allocation for the vertices
        mCubeMesh = meshBuilder.create();
        mCubeMesh.setName("CubeMesh");
        mPointAlloc = mCubeMesh.createVertexAllocation(vertexSlot);
        mPointAlloc.setName("PointBuffer");

        // Create the Allocation for the indices
        mLineIdxAlloc = mCubeMesh.createIndexAllocation();

        // Bind the allocations to the mesh
        mCubeMesh.bindVertexAllocation(mPointAlloc, 0);
        mCubeMesh.bindIndexAllocation(mLineIdxAlloc);

        /*
         *  put the vertex and index data in their respective buffers
         */
        updateWave();
        for(int i = 0; i < mIndexData.length; i ++) {
            mIndexData[i] = (short) i;
        }

        /*
         *  upload the vertex and index data
         */
        mPointAlloc.data(mPointData);
        mPointAlloc.uploadToBufferObject();
        mLineIdxAlloc.data(mIndexData);
        mLineIdxAlloc.uploadToBufferObject();

        // Time to create the script
        ScriptC.Builder sb = new ScriptC.Builder(mRS);
        // Specify the name by which to refer to the WorldState object in the
        // renderscript.
        sb.setType(mStateType, "State", RSID_STATE);
        sb.setScript(mResources, R.raw.many);
        sb.setRoot(true);

        ScriptC script = sb.create();
        script.setClearColor(0.0f, 0.0f, 0.0f, 1.0f);
        script.setTimeZone(TimeZone.getDefault().getID());

        script.bindAllocation(mState, RSID_STATE);
        script.bindAllocation(mPointAlloc, RSID_POINTS);
        script.bindAllocation(mLineIdxAlloc, RSID_LINES);
        script.bindAllocation(mPVAlloc.mAlloc, RSID_PROGRAMVERTEX);

        return script;
    }

    @Override
    public void start() {
        super.start();
        mVisible = true;
        updateWave();
    }

    @Override
    public void stop() {
        super.stop();
        mVisible = false;
    }

    void updateWave() {
        mHandler.removeCallbacks(mDrawCube);
        if (mVisible) {
            mHandler.postDelayed(mDrawCube, 20);
        }

        int len = MediaPlayer.snoop(mVizData, 0);
        
        // Simulate running the signal through a rectifier by
        // taking the average of the absolute sample values.
        int volt = 0;
        if (len > 0) {
            for (int i = 0; i < len; i++) {
                int val = mVizData[i];
                if (val < 0) {
                    val = -val;
                }
                volt += val;
            }
            volt = volt * 4 / len; // arbitrary scalar to get better range
        }

        // There are several forces working on the needle: a force applied by the
        // electromagnet, a force applied by the spring,  and friction.
        // The force from the magnet is proportional to the current flowing
        // through its coil. We have to take in to account that the coil is an
        // inductive load, which means that an immediate change in applied voltage
        // will result in a gradual change in current, but also that current will
        // be induced by the movement of the needle.
        // The force from the spring is proportional to the position of the needle.
        // The friction force is a function of the speed of the needle, but so is
        // the current induced by the movement of the needle, so we can combine
        // them.
        
        
        // Add up the various forces, with some multipliers to make the movement
        // of the needle more realistic
        // 'volt' is for the applied voltage, which causes a current to flow through the coil
        // mNeedleSpeed * 3 is for the movement of the needle, which induces an opposite current
        // in the coil, and is also proportional to the friction
        // mNeedlePos + mSpringForceAtOrigin is for the force of the spring pushing the needle back
        int netforce = volt - mNeedleSpeed * 3 - (mNeedlePos + mSpringForceAtOrigin) ;
        int acceleration = netforce / mNeedleMass;
        mNeedleSpeed += acceleration;
        mNeedlePos += mNeedleSpeed;
        if (mNeedlePos < 0) {
            mNeedlePos = 0;
            mNeedleSpeed = 0;
        } else if (mNeedlePos > 32767) {
            if (mNeedlePos > 33333) {
                 mWorldState.mPeak = 10;
            }
            mNeedlePos = 32767;
            mNeedleSpeed = 0;
        }
        if (mWorldState.mPeak > 0) {
            mWorldState.mPeak--;
        }

        mWorldState.mAngle = 131f - (mNeedlePos / 410f); // ~80 degree range
        
        // downsample 1024 samples in to 256
        
        if (len == 0) {
            if (mWorldState.mIdle == 0) {
                mWorldState.mIdle = 1;
            }
        } else {
            if (mWorldState.mIdle != 0) {
                mWorldState.mIdle = 0;
            }
            // TODO: might be more efficient to push this in to renderscript
            int outlen = mPointData.length / 8;
            len /= 4;
            if (len > outlen) len = outlen;
            for(int i = 0; i < len; i++) {
                int amp = (mVizData[i*4]  + mVizData[i*4+1] + mVizData[i*4+2] + mVizData[i*4+3]);
                mPointData[i*8+1] = amp;
                mPointData[i*8+5] = -amp;
            }
            mPointAlloc.data(mPointData);
            mWorldState.mWaveCounter++;
        }
        
        mState.data(mWorldState);
    }

}