fix normalizeForVisualization to skip extent checks for axis-swap ope…

[phaarnes]

This pull request is adding the improvement required in issue #4631.

• ✅ Closes Add option to skip extent validation in proj_normalize_for_visualization() #4631
• ✅ Test added in test_operation.cpp

proj_normalize_for_visualization() currently fails for certain concatenated coordinate operations where the sub-operations have non-overlapping validity areas. This happens because the function internally calls ConcatenatedOperation::createComputeMetadata() with checkExtent = true, which throws an exception when the validity areas do not intersect.

This PR disables the extent check for the axis-swap wrapper. It is not necessary because the axis-swap operations added by normalizeForVisualization() have no spatial effect (they only reorder coordinates), so the extent check can be safely skipped.

[phaarnes]

A simple test script to verify:

/**
 * Example: proj_normalize_for_visualization
 *
 * Test whether "always_xy" (proj_normalize_for_visualization) works
 * for ED50 to WGS84 transformations.
 *
 * Tests both:
 * - EPSG:1612 (simple Helmert, non-concatenated)
 * - EPSG:8047 (concatenated: ED50->ED87->WGS84) (note: superseded)
 *
 */

#include <cstdio>
#include <proj.h>

void test_transformation(PJ_CONTEXT *ctx, const char *op_code, double lon, double lat) {
    char urn[100];
    snprintf(urn, sizeof(urn), "urn:ogc:def:coordinateOperation:EPSG::%s", op_code);

    PJ *P = proj_create(ctx, urn);
    if (!P) {
        printf("Failed to create EPSG:%s\n\n", op_code);
        return;
    }

    printf("=== EPSG:%s ===\n", op_code);
    printf("Name: %s\n", proj_get_name(P));
    printf("Accuracy: %.2f m\n", proj_coordoperation_get_accuracy(ctx, P));

    // Test WITHOUT normalization (native axis order: lat, lon)
    printf("\nWithout normalization (native lat/lon order):\n");
    PJ_COORD input_native = proj_coord(lat, lon, 0, 0);
    PJ_COORD output_native = proj_trans(P, PJ_FWD, input_native);
    printf("  Input:  lat=%.6f, lon=%.6f\n", lat, lon);
    printf("  Output: lat=%.6f, lon=%.6f\n", output_native.lp.lam, output_native.lp.phi);

    // Test WITH normalization (always_xy: lon, lat order)
    printf("\nWith proj_normalize_for_visualization (always_xy):\n");
    PJ *P_norm = proj_normalize_for_visualization(ctx, P);
    if (P_norm) {
        PJ_COORD input_xy = proj_coord(lon, lat, 0, 0);
        PJ_COORD output_xy = proj_trans(P_norm, PJ_FWD, input_xy);
        printf("  Input:  lon=%.6f, lat=%.6f\n", lon, lat);
        printf("  Output: lon=%.6f, lat=%.6f\n", output_xy.lp.lam, output_xy.lp.phi);
        printf("  SUCCESS: always_xy works!\n");
        proj_destroy(P_norm);
    } else {
        printf("  FAILED: proj_normalize_for_visualization returned NULL\n");

    }

    proj_destroy(P);
    printf("\n");
}

int main() {
    printf("=== Testing proj_normalize_for_visualization ===\n\n");

    PJ_CONTEXT *ctx = proj_context_create();

    // Test point in Norway (valid for both transformations)
    double lon = 10.0;
    double lat = 60.0;

    printf("Test point: lon=%.4f, lat=%.4f\n\n", lon, lat);

    // Test 1: Simple (non-concatenated) transformation
    test_transformation(ctx, "1612", lon, lat);  // ED50 to WGS 84 (23) - Helmert

    // Test 2: Concatenated transformation
    test_transformation(ctx, "8047", lon, lat);  // ED50 to WGS 84 (15) - via ED87

    proj_context_destroy(ctx);

    return 0;
}

[rouault]

@phaarnes I've added a commit to your pull request to better address the issue by re-applying most of the metadata of the original operation to the normalized one (name, domain of validity, accuracy, remarks), that also avoids revalidating the domain

[phaarnes]

@rouault
Great, thanks!