Fix regression of commit de2b129a56335262a44a05541a3ab2e35668cc6e: ProjectFloat Matrix Multiplication of gluUnProject(..) impl.

ProjectFloat's previous gluMultMatricesf(..) used row-major order,
but the replacement multMatrixf(..) uses column-major order (like OpenGL, ..).

Note: The replaced 'gluMultMatrixVecf' by multMatrixVecf() already
      used column-major order.

Fix: Reverse the arguments of matrix multiplication
    m1 x m2 -> m2 x m1

Added proper API documentation in FloatUtil -> Column Major Order of Linear Matrix Layout

1 files changed, 5 insertions, 5 deletions

diff --git a/src/jogl/classes/jogamp/opengl/ProjectFloat.java b/src/jogl/classes/jogamp/opengl/ProjectFloat.java
index bce3f3cfc..ce8405f74 100644
--- a/src/jogl/classes/jogamp/opengl/ProjectFloat.java
+++ b/src/jogl/classes/jogamp/opengl/ProjectFloat.java
@@ -615,7 +615,7 @@ public class ProjectFloat {
     float[] in = this.in;
     float[] out = this.out;
 
-    FloatUtil.multMatrixf(modelMatrix, modelMatrix_offset, projMatrix, projMatrix_offset, matrix, 0);
+    FloatUtil.multMatrixf(projMatrix, projMatrix_offset, modelMatrix, modelMatrix_offset, matrix, 0);
 
     if (!gluInvertMatrixf(matrix, 0, matrix, 0)) {
       return false;
@@ -659,7 +659,7 @@ public class ProjectFloat {
     FloatBuffer in = this.inBuf;
     FloatBuffer out = this.outBuf;
 
-    FloatUtil.multMatrixf(modelMatrix, projMatrix, matrixBuf);
+    FloatUtil.multMatrixf(projMatrix, modelMatrix, matrixBuf);
 
     if (!gluInvertMatrixf(matrixBuf, matrixBuf)) {
       return false;
@@ -715,7 +715,7 @@ public class ProjectFloat {
     FloatBuffer in = this.inBuf;
     FloatBuffer out = this.outBuf;
 
-    FloatUtil.multMatrixf(modelMatrix, projMatrix, matrixBuf);
+    FloatUtil.multMatrixf(projMatrix, modelMatrix, matrixBuf);
 
     if (!gluInvertMatrixf(matrixBuf, matrixBuf)) {
       return false;
@@ -786,7 +786,7 @@ public class ProjectFloat {
     float[] in = this.in;
     float[] out = this.out;
 
-    FloatUtil.multMatrixf(modelMatrix, modelMatrix_offset, projMatrix, projMatrix_offset, matrix, 0);
+    FloatUtil.multMatrixf(projMatrix, projMatrix_offset, modelMatrix, modelMatrix_offset, matrix, 0);
 
     if (!gluInvertMatrixf(matrix, 0, matrix, 0))
       return false;
@@ -847,7 +847,7 @@ public class ProjectFloat {
     FloatBuffer in = this.inBuf;
     FloatBuffer out = this.outBuf;
 
-    FloatUtil.multMatrixf(modelMatrix, projMatrix, matrixBuf);
+    FloatUtil.multMatrixf(projMatrix, modelMatrix, matrixBuf);
 
     if (!gluInvertMatrixf(matrixBuf, matrixBuf))
       return false;