feat(brep): S13-B IGES export + format utilities

Add IGES v5.3 export for B-Rep models with: - Entity mapping: Point(116), Line(110), Circular Arc(100), B-Spline Curve(126), Plane(108), B-Spline Surface(128), Vertex(502), Edge(504), Loop(508), Face(510), Shell(514), Manifold Solid B-Rep(186) - Auto-detection of circular arcs (degree-2 NURBS with isosceles control triangle) and planes (1x1 degree surfaces) - Fixed 80-column IGES format with S/G/D/P/T sections - Header-only format_utils.h for IGES/STEP number formatting New files: - include/vde/foundation/format_utils.h - include/vde/brep/iges_export.h - src/brep/iges_export.cpp - tests/brep/test_iges_export.cpp
2026-07-24 07:34:27 +00:00
parent 092f35c3af
commit 4f75bb8b07
6 changed files with 951 additions and 0 deletions
@@ -4,3 +4,5 @@ add_vde_test(test_step_export)
 add_vde_test(test_step_import)
 add_vde_test(test_brep_boolean)
 add_vde_test(test_brep_validate)
+add_vde_test(test_iges_import)
+add_vde_test(test_iges_export)
@@ -0,0 +1,214 @@
+#include <gtest/gtest.h>
+#include "vde/brep/brep.h"
+#include "vde/brep/modeling.h"
+#include "vde/brep/iges_export.h"
+#include <fstream>
+#include <sstream>
+#include <algorithm>
+
+using namespace vde::brep;
+using namespace vde::core;
+
+// ═══════════════════════════════════════════════════════════
+//  IGES export — section structure tests
+// ═══════════════════════════════════════════════════════════
+
+TEST(IgesExportTest, ExportBox_HasSections) {
+    auto box = make_box(2, 3, 4);
+    std::string iges = export_iges({box});
+
+    // Must have all 5 sections
+    EXPECT_NE(iges.find("S0000001"), std::string::npos) << "Missing Start section";
+    EXPECT_NE(iges.find("G0000001"), std::string::npos) << "Missing Global section";
+    EXPECT_NE(iges.find("D0000001"), std::string::npos) << "Missing DE section";
+    EXPECT_NE(iges.find("P0000001"), std::string::npos) << "Missing PD section";
+    EXPECT_NE(iges.find("T0000001"), std::string::npos) << "Missing Terminate section";
+}
+
+TEST(IgesExportTest, ExportBox_HasEightyColumns) {
+    auto box = make_box(1, 1, 1);
+    std::string iges = export_iges({box});
+
+    std::istringstream iss(iges);
+    std::string line;
+    while (std::getline(iss, line)) {
+        if (line.empty()) continue;
+        EXPECT_EQ(line.size(), 80u) << "Line not 80 chars: " << line.substr(0, 40) << "...";
+    }
+}
+
+TEST(IgesExportTest, ExportBox_ContainsPointEntity) {
+    auto box = make_box(1, 1, 1);
+    std::string iges = export_iges({box});
+
+    // DE section should have type 116 (Point) entries
+    EXPECT_NE(iges.find("     116"), std::string::npos) << "Missing Point(116) entities";
+}
+
+TEST(IgesExportTest, ExportBox_ContainsLineEntity) {
+    auto box = make_box(1, 1, 1);
+    std::string iges = export_iges({box});
+
+    // Should have type 110 (Line) — box edges are straight
+    EXPECT_NE(iges.find("     110"), std::string::npos) << "Missing Line(110) entities";
+}
+
+TEST(IgesExportTest, ExportBox_ContainsPlaneEntity) {
+    auto box = make_box(1, 1, 1);
+    std::string iges = export_iges({box});
+
+    // Box faces should be detected as planes (108)
+    EXPECT_NE(iges.find("     108"), std::string::npos) << "Missing Plane(108) entities";
+}
+
+TEST(IgesExportTest, ExportBox_ContainsTopologyEntities) {
+    auto box = make_box(1, 1, 1);
+    std::string iges = export_iges({box});
+
+    EXPECT_NE(iges.find("     502"), std::string::npos) << "Missing Vertex(502)";
+    EXPECT_NE(iges.find("     504"), std::string::npos) << "Missing Edge(504)";
+    EXPECT_NE(iges.find("     508"), std::string::npos) << "Missing Loop(508)";
+    EXPECT_NE(iges.find("     510"), std::string::npos) << "Missing Face(510)";
+    EXPECT_NE(iges.find("     514"), std::string::npos) << "Missing Shell(514)";
+    EXPECT_NE(iges.find("     186"), std::string::npos) << "Missing MSBO(186)";
+}
+
+// ═══════════════════════════════════════════════════════════
+//  Cylinder export
+// ═══════════════════════════════════════════════════════════
+
+TEST(IgesExportTest, ExportCylinder_HasValidSections) {
+    auto cyl = make_cylinder(1.0, 4.0);
+    std::string iges = export_iges({cyl});
+
+    EXPECT_NE(iges.find("S0000001"), std::string::npos);
+    EXPECT_NE(iges.find("G0000001"), std::string::npos);
+    EXPECT_NE(iges.find("T0000001"), std::string::npos);
+}
+
+TEST(IgesExportTest, ExportCylinder_ContainsSurfaceEntity) {
+    auto cyl = make_cylinder(1.0, 4.0);
+    std::string iges = export_iges({cyl});
+
+    // Cylinder surface is curved → B-Spline surface (128)
+    EXPECT_NE(iges.find("     128"), std::string::npos) << "Missing B-Spline Surface(128)";
+}
+
+// ═══════════════════════════════════════════════════════════
+//  Sphere export
+// ═══════════════════════════════════════════════════════════
+
+TEST(IgesExportTest, ExportSphere_HasValidSections) {
+    auto sphere = make_sphere(2.0);
+    std::string iges = export_iges({sphere});
+
+    EXPECT_NE(iges.find("S0000001"), std::string::npos);
+    EXPECT_NE(iges.find("G0000001"), std::string::npos);
+    EXPECT_NE(iges.find("T0000001"), std::string::npos);
+}
+
+TEST(IgesExportTest, ExportSphere_ContainsBsplineSurface) {
+    auto sphere = make_sphere(2.0);
+    std::string iges = export_iges({sphere});
+
+    // Sphere should have B-Spline surfaces (128)
+    EXPECT_NE(iges.find("     128"), std::string::npos)
+        << "Sphere should export B-Spline surfaces (type 128)";
+}
+
+// ═══════════════════════════════════════════════════════════
+//  Multiple bodies
+// ═══════════════════════════════════════════════════════════
+
+TEST(IgesExportTest, ExportMultipleBodies_HasMultipleSolids) {
+    auto box1 = make_box(1, 1, 1);
+    auto box2 = make_box(2, 2, 2);
+    std::string iges = export_iges({box1, box2});
+
+    // Count MSBO (186) entities — should have at least 2
+    int count = 0;
+    size_t pos = 0;
+    while ((pos = iges.find("     186", pos)) != std::string::npos) {
+        count++;
+        pos += 8;
+    }
+    EXPECT_GE(count, 2) << "Expected at least 2 MSBO entities";
+}
+
+// ═══════════════════════════════════════════════════════════
+//  Empty model
+// ═══════════════════════════════════════════════════════════
+
+TEST(IgesExportTest, ExportEmptyModel_ProducesValidOutput) {
+    BrepModel empty;
+    std::string iges = export_iges({empty});
+
+    // Should still produce all sections
+    EXPECT_NE(iges.find("S0000001"), std::string::npos);
+    EXPECT_NE(iges.find("G0000001"), std::string::npos);
+    EXPECT_NE(iges.find("T0000001"), std::string::npos);
+
+    // Terminate section should exist with counts
+    EXPECT_NE(iges.find("T0000001"), std::string::npos);
+}
+
+// ═══════════════════════════════════════════════════════════
+//  File export
+// ═══════════════════════════════════════════════════════════
+
+TEST(IgesExportTest, ExportFile_WritesToDisk) {
+    auto box = make_box(1, 1, 1);
+    std::string path = "/tmp/test_vde_iges_export.igs";
+    export_iges_file(path, {box});
+
+    std::ifstream in(path);
+    EXPECT_TRUE(in.good());
+
+    std::string content((std::istreambuf_iterator<char>(in)),
+                         std::istreambuf_iterator<char>());
+    EXPECT_NE(content.find("S0000001"), std::string::npos);
+}
+
+// ═══════════════════════════════════════════════════════════
+//  Line count check (every line is 80 chars + \n)
+// ═══════════════════════════════════════════════════════════
+
+TEST(IgesExportTest, ExportBox_AllLinesAreEightyColumns) {
+    auto box = make_box(2, 2, 2);
+    std::string iges = export_iges({box});
+
+    std::istringstream iss(iges);
+    std::string line;
+    int line_count = 0;
+    while (std::getline(iss, line)) {
+        line_count++;
+        EXPECT_EQ(line.size(), 80u) << "Line " << line_count << " is not 80 columns";
+    }
+    EXPECT_GT(line_count, 10) << "Should have many lines";
+}
+
+// ═══════════════════════════════════════════════════════════
+//  DE section integrity: every DE line ends with Dnnnnnnn
+// ═══════════════════════════════════════════════════════════
+
+TEST(IgesExportTest, ExportBox_DELinesHaveCorrectSuffix) {
+    auto box = make_box(1, 1, 1);
+    std::string iges = export_iges({box});
+
+    int de_count = 0;
+    size_t pos = 0;
+    while ((pos = iges.find('D', pos)) != std::string::npos) {
+        // Check it's a DE line suffix (last 8 chars of a line)
+        // 'D' followed by 7 digits and then newline
+        if (pos >= 72 && iges[pos] == 'D') {
+            // Verify it's at position 72 (0-indexed) in its line
+            size_t line_start = iges.rfind('\n', pos);
+            if (line_start == std::string::npos) line_start = -1;  // first line
+            if (pos - line_start == 73) {  // 0-indexed → col 73
+                de_count++;
+            }
+        }
+        pos++;
+    }
+    EXPECT_GT(de_count, 0) << "Should have DE lines with D suffix";
+}