This is an automated email from the ASF dual-hosted git repository.
desruisseaux pushed a commit to branch geoapi-4.0
in repository https://gitbox.apache.org/repos/asf/sis.git
commit 200602de57efe00097430b48532f0b47f97f2928
Author: Martin Desruisseaux <martin.desruisse...@geomatys.com>
AuthorDate: Mon May 2 17:45:00 2022 +0200
Make the `qm(sinφ)` method always safe to the spherical case.
The reason is because `Spherical` inner classes are not public.
Consequently users creating their own map projection subclasses could have
a non-working instance.
---
.../operation/projection/AlbersEqualArea.java | 2 +-
.../operation/projection/CylindricalEqualArea.java | 8 ++++----
.../operation/projection/EqualAreaProjection.java | 18 +++++-------------
3 files changed, 10 insertions(+), 18 deletions(-)
diff --git
a/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/projection/AlbersEqualArea.java
b/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/projection/AlbersEqualArea.java
index fcfd6f0866..c72a3df34d 100644
---
a/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/projection/AlbersEqualArea.java
+++
b/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/projection/AlbersEqualArea.java
@@ -244,7 +244,7 @@ public class AlbersEqualArea extends EqualAreaProjection {
final double cosθ = cos(θ);
final double sinθ = sin(θ);
final double sinφ = sin(φ);
- final double ρ = sqrt(C - nm*qm_ellipsoid(sinφ));
+ final double ρ = sqrt(C - nm*qm(sinφ));
if (dstPts != null) {
dstPts[dstOff ] = ρ * sinθ;
dstPts[dstOff+1] = ρ * cosθ;
diff --git
a/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/projection/CylindricalEqualArea.java
b/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/projection/CylindricalEqualArea.java
index a7f808b015..8ecd0f4b67 100644
---
a/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/projection/CylindricalEqualArea.java
+++
b/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/projection/CylindricalEqualArea.java
@@ -246,8 +246,8 @@ public class CylindricalEqualArea extends
EqualAreaProjection {
final double φ = srcPts[srcOff+1];
final double sinφ = sin(φ);
if (dstPts != null) {
- dstPts[dstOff ] = srcPts[srcOff]; // Multiplication by k₀
will be applied by the denormalization matrix.
- dstPts[dstOff+1] = qm_ellipsoid(sinφ); // Multiplication by
(1-ℯ²)/(2k₀) will be applied by the denormalization matrix.
+ dstPts[dstOff ] = srcPts[srcOff]; // Multiplication by k₀ will
be applied by the denormalization matrix.
+ dstPts[dstOff+1] = qm(sinφ); // Multiplication by
(1-ℯ²)/(2k₀) will be applied by the denormalization matrix.
}
/*
* End of map projection. Now compute the derivative, if requested.
@@ -275,8 +275,8 @@ public class CylindricalEqualArea extends
EqualAreaProjection {
*/
dstOff--;
while (--numPts >= 0) {
- final double φ = dstPts[dstOff += DIMENSION]; //
Same as srcPts[srcOff + 1].
- dstPts[dstOff] = qm_ellipsoid(sin(φ)); //
Part of Snyder equation (10-15)
+ final double φ = dstPts[dstOff += DIMENSION]; // Same as
srcPts[srcOff + 1].
+ dstPts[dstOff] = qm(sin(φ)); // Part of
Snyder equation (10-15)
}
}
}
diff --git
a/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/projection/EqualAreaProjection.java
b/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/projection/EqualAreaProjection.java
index 3abebb6a42..06691ef8c3 100644
---
a/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/projection/EqualAreaProjection.java
+++
b/core/sis-referencing/src/main/java/org/apache/sis/referencing/operation/projection/EqualAreaProjection.java
@@ -170,28 +170,20 @@ abstract class EqualAreaProjection extends
NormalizedProjection {
* <li>q(0) = 0</li>
* </ul>
*
+ * <h4>Spherical case</h4>
* In the spherical case, <var>q</var> = 2⋅sinφ.
+ * We pay the cost of checking for the spherical case in each method
invocation because otherwise,
+ * users creating their own map projection subclasses could get a
non-working implementation.
*
* @param sinφ the sine of the latitude <var>q</var> is calculated for.
* @return <var>q</var> from Snyder equation (3-12).
*/
final double qm(final double sinφ) {
/*
- * Check for zero eccentricity is required because qm_ellipsoid(sinφ)
would
+ * Check for zero eccentricity is required because `qm(sinφ)` would
* simplify to sinφ + atanh(0) / 0 == sinφ + 0/0, thus producing NaN.
*/
- return isSpherical ? 2*sinφ : qm_ellipsoid(sinφ);
- }
-
- /**
- * Same as {@link #qm(double)} but without check about whether the map
projection is a spherical case.
- * It is caller responsibility to ensure that this method is not invoked
in the spherical case, since
- * this implementation does not work in such case.
- *
- * @param sinφ the sine of the latitude <var>q</var> is calculated for.
- * @return <var>q</var> from Snyder equation (3-12).
- */
- final double qm_ellipsoid(final double sinφ) {
+ if (isSpherical) return 2*sinφ;
final double ℯsinφ = eccentricity * sinφ;
return sinφ / (1 - ℯsinφ*ℯsinφ) + atanh(ℯsinφ) / eccentricity;
}
