Java tutorial
/* * Copyright (C) 2006 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 android.graphics; import android.annotation.UnsupportedAppUsage; /** * A camera instance can be used to compute 3D transformations and * generate a matrix that can be applied, for instance, on a * {@link Canvas}. */ public class Camera { private Matrix mMatrix; /** * Creates a new camera, with empty transformations. */ public Camera() { nativeConstructor(); } /** * Saves the camera state. Each save should be balanced * with a call to {@link #restore()}. * * @see #save() */ public native void save(); /** * Restores the saved state, if any. * * @see #restore() */ public native void restore(); /** * Applies a translation transform on all three axis. * * @param x The distance to translate by on the X axis * @param y The distance to translate by on the Y axis * @param z The distance to translate by on the Z axis */ public native void translate(float x, float y, float z); /** * Applies a rotation transform around the X axis. * * @param deg The angle of rotation around the X axis, in degrees * * @see #rotateY(float) * @see #rotateZ(float) * @see #rotate(float, float, float) */ public native void rotateX(float deg); /** * Applies a rotation transform around the Y axis. * * @param deg The angle of rotation around the Y axis, in degrees * * @see #rotateX(float) * @see #rotateZ(float) * @see #rotate(float, float, float) */ public native void rotateY(float deg); /** * Applies a rotation transform around the Z axis. * * @param deg The angle of rotation around the Z axis, in degrees * * @see #rotateX(float) * @see #rotateY(float) * @see #rotate(float, float, float) */ public native void rotateZ(float deg); /** * Applies a rotation transform around all three axis. * * @param x The angle of rotation around the X axis, in degrees * @param y The angle of rotation around the Y axis, in degrees * @param z The angle of rotation around the Z axis, in degrees * * @see #rotateX(float) * @see #rotateY(float) * @see #rotateZ(float) */ public native void rotate(float x, float y, float z); /** * Gets the x location of the camera. * * @see #setLocation(float, float, float) */ public native float getLocationX(); /** * Gets the y location of the camera. * * @see #setLocation(float, float, float) */ public native float getLocationY(); /** * Gets the z location of the camera. * * @see #setLocation(float, float, float) */ public native float getLocationZ(); /** * Sets the location of the camera. The default location is set at * 0, 0, -8. * * @param x The x location of the camera * @param y The y location of the camera * @param z The z location of the camera */ public native void setLocation(float x, float y, float z); /** * Computes the matrix corresponding to the current transformation * and copies it to the supplied matrix object. * * @param matrix The matrix to copy the current transforms into */ public void getMatrix(Matrix matrix) { nativeGetMatrix(matrix.native_instance); } /** * Computes the matrix corresponding to the current transformation * and applies it to the specified Canvas. * * @param canvas The Canvas to set the transform matrix onto */ public void applyToCanvas(Canvas canvas) { if (canvas.isHardwareAccelerated()) { if (mMatrix == null) mMatrix = new Matrix(); getMatrix(mMatrix); canvas.concat(mMatrix); } else { nativeApplyToCanvas(canvas.getNativeCanvasWrapper()); } } public native float dotWithNormal(float dx, float dy, float dz); protected void finalize() throws Throwable { try { nativeDestructor(); native_instance = 0; } finally { super.finalize(); } } private native void nativeConstructor(); private native void nativeDestructor(); private native void nativeGetMatrix(long native_matrix); private native void nativeApplyToCanvas(long native_canvas); @UnsupportedAppUsage long native_instance; }