diff options
Diffstat (limited to 'src/jogl/classes/com/jogamp/opengl/math')
| -rw-r--r-- | src/jogl/classes/com/jogamp/opengl/math/FloatUtil.java | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/src/jogl/classes/com/jogamp/opengl/math/FloatUtil.java b/src/jogl/classes/com/jogamp/opengl/math/FloatUtil.java index 9d3ee412b..cf56ff0a4 100644 --- a/src/jogl/classes/com/jogamp/opengl/math/FloatUtil.java +++ b/src/jogl/classes/com/jogamp/opengl/math/FloatUtil.java @@ -29,6 +29,8 @@ package com.jogamp.opengl.math; import java.nio.FloatBuffer; +import javax.media.opengl.GLException; + import jogamp.opengl.Debug; import com.jogamp.common.os.Platform; @@ -199,6 +201,123 @@ public class FloatUtil { } /** + * Make given matrix the orthogonal matrix based on given parameters. + * + * @param a 4x4 matrix in column-major order (also result) + * @param a_off + * @param initA if true, given matrix will be initialized w/ identity matrix. + * @param left + * @param right + * @param bottom + * @param top + * @param zNear + * @param zFar + * @return given matrix for chaining + */ + public static final float[] makeOrthof(final float[] a, final int a_off, final boolean initA, + final float left, final float right, + final float bottom, final float top, + final float zNear, final float zFar) { + if( initA ) { + FloatUtil.makeIdentityf(a, a_off); + } + // Ortho matrix (Column Order): + // 2/dx 0 0 0 + // 0 2/dy 0 0 + // 0 0 2/dz 0 + // tx ty tz 1 + final float dx=right-left; + final float dy=top-bottom; + final float dz=zFar-zNear; + final float tx=-1.0f*(right+left)/dx; + final float ty=-1.0f*(top+bottom)/dy; + final float tz=-1.0f*(zFar+zNear)/dz; + + a[a_off+0+4*0] = 2.0f/dx; + a[a_off+1+4*1] = 2.0f/dy; + a[a_off+2+4*2] = -2.0f/dz; + a[a_off+0+4*3] = tx; + a[a_off+1+4*3] = ty; + a[a_off+2+4*3] = tz; + + return a; + } + + /** + * Make given matrix the frustum matrix based on given parameters. + * + * @param a 4x4 matrix in column-major order (also result) + * @param a_off + * @param initA if true, given matrix will be initialized w/ identity matrix. + * @param left + * @param right + * @param bottom + * @param top + * @param zNear + * @param zFar + * @return given matrix for chaining + */ + public static final float[] makeFrustumf(final float[] a, final int a_off, final boolean initA, + final float left, final float right, + final float bottom, final float top, + final float zNear, final float zFar) { + if(zNear<=0.0f||zFar<0.0f) { + throw new GLException("GL_INVALID_VALUE: zNear and zFar must be positive, and zNear>0"); + } + if(left==right || top==bottom) { + throw new GLException("GL_INVALID_VALUE: top,bottom and left,right must not be equal"); + } + if( initA ) { + FloatUtil.makeIdentityf(a, a_off); + } + // Frustum matrix (Column Order): + // 2*zNear/dx 0 0 0 + // 0 2*zNear/dy 0 0 + // A B C -1 + // 0 0 D 0 + final float zNear2 = 2.0f*zNear; + final float dx=right-left; + final float dy=top-bottom; + final float dz=zFar-zNear; + final float A=(right+left)/dx; + final float B=(top+bottom)/dy; + final float C=-1.0f*(zFar+zNear)/dz; + final float D=-2.0f*(zFar*zNear)/dz; + + a[a_off+0+4*0] = zNear2/dx; + a[a_off+1+4*1] = zNear2/dy; + a[a_off+2+4*2] = C; + + a[a_off+0+4*2] = A; + a[a_off+1+4*2] = B; + + a[a_off+2+4*3] = D; + a[a_off+3+4*2] = -1.0f; + return a; + } + + /** + * Make given matrix the perspective matrix based on given parameters. + * + * @param a 4x4 matrix in column-major order (also result) + * @param a_off + * @param initA if true, given matrix will be initialized w/ identity matrix. + * @param fovy angle in radians + * @param aspect + * @param zNear + * @param zFar + * @return given matrix for chaining + */ + public static final float[] makePerspective(final float[] a, final int a_off, final boolean initA, + final float fovy, final float aspect, final float zNear, final float zFar) { + float top=(float)Math.tan(fovy)*zNear; + float bottom=-1.0f*top; + float left=aspect*bottom; + float right=aspect*top; + return makeFrustumf(a, a_off, initA, left, right, bottom, top, zNear, zFar); + } + + /** * Multiply matrix: [d] = [a] x [b] * @param a 4x4 matrix in column-major order * @param b 4x4 matrix in column-major order @@ -840,4 +959,47 @@ public class FloatUtil { public static float sqrt(final float a) { return (float) java.lang.Math.sqrt(a); } + /** + * Returns resolution of Z buffer of given parameter, + * see <a href="http://www.sjbaker.org/steve/omniv/love_your_z_buffer.html">Love Your Z-Buffer</a>. + * <pre> + * return z * z / ( zNear * (1<<zBits) - z ) + * </pre> + * @param zBits number of bits of Z precision, i.e. z-buffer depth + * @param z distance from the eye to the object + * @param zNear distance from eye to near clip plane + * @return smallest resolvable Z separation at this range. + */ + public static float getZBufferEpsilon(final int zBits, final float z, final float zNear) { + return z * z / ( zNear * ( 1 << zBits ) - z ); + } + + /** + * Returns Z buffer value of given parameter, + * see <a href="http://www.sjbaker.org/steve/omniv/love_your_z_buffer.html">Love Your Z-Buffer</a>. + * <pre> + * float a = zFar / ( zFar - zNear ) + * float b = zFar * zNear / ( zNear - zFar ) + * return (int) ( (1<<zBits) * ( a + b / z ) ) + * </pre> + * @param zBits number of bits of Z precision, i.e. z-buffer depth + * @param z distance from the eye to the object + * @param zNear distance from eye to near clip plane + * @param zFar distance from eye to far clip plane + * @return z buffer value + */ + public static int getZBufferValue(final int zBits, final float z, final float zNear, final float zFar) { + final float a = zFar / ( zFar - zNear ); + final float b = zFar * zNear / ( zNear - zFar ); + return (int) ( (1<<zBits) * ( a + b / z ) ); + } + + /** + * Returns orthogonal distance + * (1f/zNear-1f/orthoDist)/(1f/zNear-1f/zFar); + */ + public static float getOrthoWinZ(final float orthoZ, final float zNear, final float zFar) { + return (1f/zNear-1f/orthoZ)/(1f/zNear-1f/zFar); + } + }
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