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Diffstat (limited to 'demos/RonsDemos/MatrixFuncs.java')
| -rw-r--r-- | demos/RonsDemos/MatrixFuncs.java | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/demos/RonsDemos/MatrixFuncs.java b/demos/RonsDemos/MatrixFuncs.java new file mode 100644 index 0000000..75493a2 --- /dev/null +++ b/demos/RonsDemos/MatrixFuncs.java @@ -0,0 +1,200 @@ +/**
+ * @(#) MatrixFuncs.java
+ * @(#) author: Ronald B. Cemer
+ * @(#) version: 1.0
+ */
+
+import java.io.*;
+
+public class MatrixFuncs
+{
+ public static final float M_PI = 3.14159265359f;
+
+ // Given the angle in degs, create a 4x4 matrix
+ // in mtx which rotates around the X axis.
+ public void rotateAroundX(float degs, float mtx[])
+ {
+ float rads, rsin, rcos;
+
+ rads = degs*(M_PI/180.0f);
+ rsin = (float)Math.sin(rads);
+ rcos = (float)Math.cos(rads);
+ mtx[0] = 1.0f;
+ mtx[1] = 0.0f;
+ mtx[2] = 0.0f;
+ mtx[3] = 0.0f;
+ mtx[4] = 0.0f;
+ mtx[5] = rcos;
+ mtx[6] = rsin;
+ mtx[7] = 0.0f;
+ mtx[8] = 0.0f;
+ mtx[9] = -rsin;
+ mtx[10] = rcos;
+ mtx[11] = 0.0f;
+ mtx[12] = 0.0f;
+ mtx[13] = 0.0f;
+ mtx[14] = 0.0f;
+ mtx[15] = 1.0f;
+ }
+
+ // Given the angle in degs, create a 4x4 matrix
+ // in mtx which rotates around the Y axis.
+ public void rotateAroundY(float degs, float mtx[])
+ {
+ float rads, rsin, rcos;
+
+ rads = degs*(M_PI/180.0f);
+ rsin = (float)Math.sin(rads);
+ rcos = (float)Math.cos(rads);
+ mtx[0] = rcos;
+ mtx[1] = 0.0f;
+ mtx[2] = -rsin;
+ mtx[3] = 0.0f;
+ mtx[4] = 0.0f;
+ mtx[5] = 1.0f;
+ mtx[6] = 0.0f;
+ mtx[7] = 0.0f;
+ mtx[8] = rsin;
+ mtx[9] = 0.0f;
+ mtx[10] = rcos;
+ mtx[11] = 0.0f;
+ mtx[12] = 0.0f;
+ mtx[13] = 0.0f;
+ mtx[14] = 0.0f;
+ mtx[15] = 1.0f;
+ }
+
+ // Given the angle in degs, create a 4x4 matrix
+ // in mtx which rotates around the Z axis.
+ public void rotateAroundZ(float degs, float mtx[])
+ {
+ float rads, rsin, rcos;
+
+ rads = degs*(M_PI/180.0f);
+ rsin = (float)Math.sin(rads);
+ rcos = (float)Math.cos(rads);
+ mtx[0] = rcos;
+ mtx[1] = rsin;
+ mtx[2] = 0.0f;
+ mtx[3] = 0.0f;
+ mtx[4] = -rsin;
+ mtx[5] = rcos;
+ mtx[6] = 0.0f;
+ mtx[7] = 0.0f;
+ mtx[8] = 0.0f;
+ mtx[9] = 0.0f;
+ mtx[10] = 1.0f;
+ mtx[11] = 0.0f;
+ mtx[12] = 0.0f;
+ mtx[13] = 0.0f;
+ mtx[14] = 0.0f;
+ mtx[15] = 1.0f;
+ }
+
+ // Given two 4x4 matrices in mtx1 and mtx2, multiply
+ // them and put the result in dest.
+ // This routine uses a temporary buffer for the result,
+ // so if dest is the same as mtx1 or mtx2, it will still
+ // work properly.
+ public void multiplyMatrices(float mtx1[], float mtx2[], float dest[])
+ {
+ float nmtx[] = new float[16];
+
+ nmtx[0] =
+ (mtx1[0]*mtx2[0]) +
+ (mtx1[1]*mtx2[4]) +
+ (mtx1[2]*mtx2[8]) +
+ (mtx1[3]*mtx2[12]);
+ nmtx[1] =
+ (mtx1[0]*mtx2[1]) +
+ (mtx1[1]*mtx2[5]) +
+ (mtx1[2]*mtx2[9]) +
+ (mtx1[3]*mtx2[13]);
+ nmtx[2] =
+ (mtx1[0]*mtx2[2]) +
+ (mtx1[1]*mtx2[6]) +
+ (mtx1[2]*mtx2[10]) +
+ (mtx1[3]*mtx2[14]);
+ nmtx[3] =
+ (mtx1[0]*mtx2[3]) +
+ (mtx1[1]*mtx2[7]) +
+ (mtx1[2]*mtx2[11]) +
+ (mtx1[3]*mtx2[15]);
+ nmtx[4] =
+ (mtx1[4]*mtx2[0]) +
+ (mtx1[5]*mtx2[4]) +
+ (mtx1[6]*mtx2[8]) +
+ (mtx1[7]*mtx2[12]);
+ nmtx[5] =
+ (mtx1[4]*mtx2[1]) +
+ (mtx1[5]*mtx2[5]) +
+ (mtx1[6]*mtx2[9]) +
+ (mtx1[7]*mtx2[13]);
+ nmtx[6] =
+ (mtx1[4]*mtx2[2]) +
+ (mtx1[5]*mtx2[6]) +
+ (mtx1[6]*mtx2[10]) +
+ (mtx1[7]*mtx2[14]);
+ nmtx[7] =
+ (mtx1[4]*mtx2[3]) +
+ (mtx1[5]*mtx2[7]) +
+ (mtx1[6]*mtx2[11]) +
+ (mtx1[7]*mtx2[15]);
+ nmtx[8] =
+ (mtx1[8]*mtx2[0]) +
+ (mtx1[9]*mtx2[4]) +
+ (mtx1[10]*mtx2[8]) +
+ (mtx1[11]*mtx2[12]);
+ nmtx[9] =
+ (mtx1[8]*mtx2[1]) +
+ (mtx1[9]*mtx2[5]) +
+ (mtx1[10]*mtx2[9]) +
+ (mtx1[11]*mtx2[13]);
+ nmtx[10] =
+ (mtx1[8]*mtx2[2]) +
+ (mtx1[9]*mtx2[6]) +
+ (mtx1[10]*mtx2[10]) +
+ (mtx1[11]*mtx2[14]);
+ nmtx[11] =
+ (mtx1[8]*mtx2[3]) +
+ (mtx1[9]*mtx2[7]) +
+ (mtx1[10]*mtx2[11]) +
+ (mtx1[11]*mtx2[15]);
+ nmtx[12] =
+ (mtx1[12]*mtx2[0]) +
+ (mtx1[13]*mtx2[4]) +
+ (mtx1[14]*mtx2[8]) +
+ (mtx1[15]*mtx2[12]);
+ nmtx[13] =
+ (mtx1[12]*mtx2[1]) +
+ (mtx1[13]*mtx2[5]) +
+ (mtx1[14]*mtx2[9]) +
+ (mtx1[15]*mtx2[13]);
+ nmtx[14] =
+ (mtx1[12]*mtx2[2]) +
+ (mtx1[13]*mtx2[6]) +
+ (mtx1[14]*mtx2[10]) +
+ (mtx1[15]*mtx2[14]);
+ nmtx[15] =
+ (mtx1[12]*mtx2[3]) +
+ (mtx1[13]*mtx2[7]) +
+ (mtx1[14]*mtx2[11]) +
+ (mtx1[15]*mtx2[15]);
+ dest[0] = nmtx[0];
+ dest[1] = nmtx[1];
+ dest[2] = nmtx[2];
+ dest[3] = nmtx[3];
+ dest[4] = nmtx[4];
+ dest[5] = nmtx[5];
+ dest[6] = nmtx[6];
+ dest[7] = nmtx[7];
+ dest[8] = nmtx[8];
+ dest[9] = nmtx[9];
+ dest[10] = nmtx[10];
+ dest[11] = nmtx[11];
+ dest[12] = nmtx[12];
+ dest[13] = nmtx[13];
+ dest[14] = nmtx[14];
+ dest[15] = nmtx[15];
+ }
+}
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