/*
* Copyright (C) 2009-2012 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.renderscript;
import java.lang.Math;
/**
* Class for exposing the native RenderScript rs_matrix4x4 type back to the Android system.
*
**/
public class Matrix4f {
/**
* Creates a new identity 4x4 matrix
*/
public Matrix4f() {
mMat = new float[16];
loadIdentity();
}
/**
* Creates a new matrix and sets its values from the given
* parameter
*
* @param dataArray values to set the matrix to, must be 16
* floats long
*/
public Matrix4f(float[] dataArray) {
mMat = new float[16];
System.arraycopy(dataArray, 0, mMat, 0, mMat.length);
}
/**
* Return a reference to the internal array representing matrix
* values. Modifying this array will also change the matrix
*
* @return internal array representing the matrix
*/
public float[] getArray() {
return mMat;
}
/**
* Returns the value for a given row and column
*
* @param x column of the value to return
* @param y row of the value to return
*
* @return value in the yth row and xth column
*/
public float get(int x, int y) {
return mMat[x*4 + y];
}
/**
* Sets the value for a given row and column
*
* @param x column of the value to set
* @param y row of the value to set
*/
public void set(int x, int y, float v) {
mMat[x*4 + y] = v;
}
/**
* Sets the matrix values to identity
*/
public void loadIdentity() {
mMat[0] = 1;
mMat[1] = 0;
mMat[2] = 0;
mMat[3] = 0;
mMat[4] = 0;
mMat[5] = 1;
mMat[6] = 0;
mMat[7] = 0;
mMat[8] = 0;
mMat[9] = 0;
mMat[10] = 1;
mMat[11] = 0;
mMat[12] = 0;
mMat[13] = 0;
mMat[14] = 0;
mMat[15] = 1;
}
/**
* Sets the values of the matrix to those of the parameter
*
* @param src matrix to load the values from
*/
public void load(Matrix4f src) {
System.arraycopy(src.getArray(), 0, mMat, 0, mMat.length);
}
/**
* Sets the values of the matrix to those of the parameter
*
* @param src matrix to load the values from
* @hide
*/
public void load(Matrix3f src) {
mMat[0] = src.mMat[0];
mMat[1] = src.mMat[1];
mMat[2] = src.mMat[2];
mMat[3] = 0;
mMat[4] = src.mMat[3];
mMat[5] = src.mMat[4];
mMat[6] = src.mMat[5];
mMat[7] = 0;
mMat[8] = src.mMat[6];
mMat[9] = src.mMat[7];
mMat[10] = src.mMat[8];
mMat[11] = 0;
mMat[12] = 0;
mMat[13] = 0;
mMat[14] = 0;
mMat[15] = 1;
}
/**
* Sets current values to be a rotation matrix of certain angle
* about a given axis
*
* @param rot angle of rotation
* @param x rotation axis x
* @param y rotation axis y
* @param z rotation axis z
*/
public void loadRotate(float rot, float x, float y, float z) {
float c, s;
mMat[3] = 0;
mMat[7] = 0;
mMat[11]= 0;
mMat[12]= 0;
mMat[13]= 0;
mMat[14]= 0;
mMat[15]= 1;
rot *= (float)(java.lang.Math.PI / 180.0f);
c = (float)java.lang.Math.cos(rot);
s = (float)java.lang.Math.sin(rot);
float len = (float)java.lang.Math.sqrt(x*x + y*y + z*z);
if (!(len != 1)) {
float recipLen = 1.f / len;
x *= recipLen;
y *= recipLen;
z *= recipLen;
}
float nc = 1.0f - c;
float xy = x * y;
float yz = y * z;
float zx = z * x;
float xs = x * s;
float ys = y * s;
float zs = z * s;
mMat[ 0] = x*x*nc + c;
mMat[ 4] = xy*nc - zs;
mMat[ 8] = zx*nc + ys;
mMat[ 1] = xy*nc + zs;
mMat[ 5] = y*y*nc + c;
mMat[ 9] = yz*nc - xs;
mMat[ 2] = zx*nc - ys;
mMat[ 6] = yz*nc + xs;
mMat[10] = z*z*nc + c;
}
/**
* Sets current values to be a scale matrix of given dimensions
*
* @param x scale component x
* @param y scale component y
* @param z scale component z
*/
public void loadScale(float x, float y, float z) {
loadIdentity();
mMat[0] = x;
mMat[5] = y;
mMat[10] = z;
}
/**
* Sets current values to be a translation matrix of given
* dimensions
*
* @param x translation component x
* @param y translation component y
* @param z translation component z
*/
public void loadTranslate(float x, float y, float z) {
loadIdentity();
mMat[12] = x;
mMat[13] = y;
mMat[14] = z;
}
/**
* Sets current values to be the result of multiplying two given
* matrices
*
* @param lhs left hand side matrix
* @param rhs right hand side matrix
*/
public void loadMultiply(Matrix4f lhs, Matrix4f rhs) {
for (int i=0 ; i<4 ; i++) {
float ri0 = 0;
float ri1 = 0;
float ri2 = 0;
float ri3 = 0;
for (int j=0 ; j<4 ; j++) {
float rhs_ij = rhs.get(i,j);
ri0 += lhs.get(j,0) * rhs_ij;
ri1 += lhs.get(j,1) * rhs_ij;
ri2 += lhs.get(j,2) * rhs_ij;
ri3 += lhs.get(j,3) * rhs_ij;
}
set(i,0, ri0);
set(i,1, ri1);
set(i,2, ri2);
set(i,3, ri3);
}
}
/**
* Set current values to be an orthographic projection matrix
*
* @param l location of the left vertical clipping plane
* @param r location of the right vertical clipping plane
* @param b location of the bottom horizontal clipping plane
* @param t location of the top horizontal clipping plane
* @param n location of the near clipping plane
* @param f location of the far clipping plane
*/
public void loadOrtho(float l, float r, float b, float t, float n, float f) {
loadIdentity();
mMat[0] = 2 / (r - l);
mMat[5] = 2 / (t - b);
mMat[10]= -2 / (f - n);
mMat[12]= -(r + l) / (r - l);
mMat[13]= -(t + b) / (t - b);
mMat[14]= -(f + n) / (f - n);
}
/**
* Set current values to be an orthographic projection matrix
* with the right and bottom clipping planes set to the given
* values. Left and top clipping planes are set to 0. Near and
* far are set to -1, 1 respectively
*
* @param w location of the right vertical clipping plane
* @param h location of the bottom horizontal clipping plane
*
*/
public void loadOrthoWindow(int w, int h) {
loadOrtho(0,w, h,0, -1,1);
}
/**
* Sets current values to be a perspective projection matrix
*
* @param l location of the left vertical clipping plane
* @param r location of the right vertical clipping plane
* @param b location of the bottom horizontal clipping plane
* @param t location of the top horizontal clipping plane
* @param n location of the near clipping plane, must be positive
* @param f location of the far clipping plane, must be positive
*
*/
public void loadFrustum(float l, float r, float b, float t, float n, float f) {
loadIdentity();
mMat[0] = 2 * n / (r - l);
mMat[5] = 2 * n / (t - b);
mMat[8] = (r + l) / (r - l);
mMat[9] = (t + b) / (t - b);
mMat[10]= -(f + n) / (f - n);
mMat[11]= -1;
mMat[14]= -2*f*n / (f - n);
mMat[15]= 0;
}
/**
* Sets current values to be a perspective projection matrix
*
* @param fovy vertical field of view angle in degrees
* @param aspect aspect ratio of the screen
* @param near near cliping plane, must be positive
* @param far far clipping plane, must be positive
*/
public void loadPerspective(float fovy, float aspect, float near, float far) {
float top = near * (float)Math.tan((float) (fovy * Math.PI / 360.0f));
float bottom = -top;
float left = bottom * aspect;
float right = top * aspect;
loadFrustum(left, right, bottom, top, near, far);
}
/**
* Helper function to set the current values to a perspective
* projection matrix with aspect ratio defined by the parameters
* and (near, far), (bottom, top) mapping to (-1, 1) at z = 0
*
* @param w screen width
* @param h screen height
*/
public void loadProjectionNormalized(int w, int h) {
// range -1,1 in the narrow axis at z = 0.
Matrix4f m1 = new Matrix4f();
Matrix4f m2 = new Matrix4f();
if(w > h) {
float aspect = ((float)w) / h;
m1.loadFrustum(-aspect,aspect, -1,1, 1,100);
} else {
float aspect = ((float)h) / w;
m1.loadFrustum(-1,1, -aspect,aspect, 1,100);
}
m2.loadRotate(180, 0, 1, 0);
m1.loadMultiply(m1, m2);
m2.loadScale(-2, 2, 1);
m1.loadMultiply(m1, m2);
m2.loadTranslate(0, 0, 2);
m1.loadMultiply(m1, m2);
load(m1);
}
/**
* Post-multiplies the current matrix by a given parameter
*
* @param rhs right hand side to multiply by
*/
public void multiply(Matrix4f rhs) {
Matrix4f tmp = new Matrix4f();
tmp.loadMultiply(this, rhs);
load(tmp);
}
/**
* Modifies the current matrix by post-multiplying it with a
* rotation matrix of certain angle about a given axis
*
* @param rot angle of rotation
* @param x rotation axis x
* @param y rotation axis y
* @param z rotation axis z
*/
public void rotate(float rot, float x, float y, float z) {
Matrix4f tmp = new Matrix4f();
tmp.loadRotate(rot, x, y, z);
multiply(tmp);
}
/**
* Modifies the current matrix by post-multiplying it with a
* scale matrix of given dimensions
*
* @param x scale component x
* @param y scale component y
* @param z scale component z
*/
public void scale(float x, float y, float z) {
Matrix4f tmp = new Matrix4f();
tmp.loadScale(x, y, z);
multiply(tmp);
}
/**
* Modifies the current matrix by post-multiplying it with a
* translation matrix of given dimensions
*
* @param x translation component x
* @param y translation component y
* @param z translation component z
*/
public void translate(float x, float y, float z) {
Matrix4f tmp = new Matrix4f();
tmp.loadTranslate(x, y, z);
multiply(tmp);
}
private float computeCofactor(int i, int j) {
int c0 = (i+1) % 4;
int c1 = (i+2) % 4;
int c2 = (i+3) % 4;
int r0 = (j+1) % 4;
int r1 = (j+2) % 4;
int r2 = (j+3) % 4;
float minor = (mMat[c0 + 4*r0] * (mMat[c1 + 4*r1] * mMat[c2 + 4*r2] -
mMat[c1 + 4*r2] * mMat[c2 + 4*r1]))
- (mMat[c0 + 4*r1] * (mMat[c1 + 4*r0] * mMat[c2 + 4*r2] -
mMat[c1 + 4*r2] * mMat[c2 + 4*r0]))
+ (mMat[c0 + 4*r2] * (mMat[c1 + 4*r0] * mMat[c2 + 4*r1] -
mMat[c1 + 4*r1] * mMat[c2 + 4*r0]));
float cofactor = ((i+j) & 1) != 0 ? -minor : minor;
return cofactor;
}
/**
* Sets the current matrix to its inverse
*/
public boolean inverse() {
Matrix4f result = new Matrix4f();
for (int i = 0; i < 4; ++i) {
for (int j = 0; j < 4; ++j) {
result.mMat[4*i + j] = computeCofactor(i, j);
}
}
// Dot product of 0th column of source and 0th row of result
float det = mMat[0]*result.mMat[0] + mMat[4]*result.mMat[1] +
mMat[8]*result.mMat[2] + mMat[12]*result.mMat[3];
if (Math.abs(det) < 1e-6) {
return false;
}
det = 1.0f / det;
for (int i = 0; i < 16; ++i) {
mMat[i] = result.mMat[i] * det;
}
return true;
}
/**
* Sets the current matrix to its inverse transpose
*/
public boolean inverseTranspose() {
Matrix4f result = new Matrix4f();
for (int i = 0; i < 4; ++i) {
for (int j = 0; j < 4; ++j) {
result.mMat[4*j + i] = computeCofactor(i, j);
}
}
float det = mMat[0]*result.mMat[0] + mMat[4]*result.mMat[4] +
mMat[8]*result.mMat[8] + mMat[12]*result.mMat[12];
if (Math.abs(det) < 1e-6) {
return false;
}
det = 1.0f / det;
for (int i = 0; i < 16; ++i) {
mMat[i] = result.mMat[i] * det;
}
return true;
}
/**
* Sets the current matrix to its transpose
*/
public void transpose() {
for(int i = 0; i < 3; ++i) {
for(int j = i + 1; j < 4; ++j) {
float temp = mMat[i*4 + j];
mMat[i*4 + j] = mMat[j*4 + i];
mMat[j*4 + i] = temp;
}
}
}
final float[] mMat;
}
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