feat: Add export settings functionality and related tests

- Introduced ExportSettings.h for managing export configurations including size presets, quality settings, and background modes.
- Implemented validation functions for export dimensions and aspect ratio locking.
- Added new enums for export formats and quality modes.
- Enhanced Application.h to include export settings and related properties.
- Updated PlotPanel to conditionally render a canvas border based on user settings.
- Bumped version to 1.5.1 to reflect new features.
- Created ExportSettingsTests.cpp to cover unit tests for export settings logic.

Author: russlank

README.md

@@ -18,7 +18,7 @@ The app supports:
 - `f(x,y,z)` scalar-field cross-sections at configurable `z` slices
 - `F(x,y,z)=0` implicit 3D surfaces (e.g. spheres and torus equations)
 - Auto/Force 2D/3D rendering preference with projected 3D grid-plane interleaving (`z=0`) for clearer depth ordering
-- Plot export dialog (size/aspect, color or grayscale, background color, include/exclude grid/coordinates/wires) with `.png`/`.bmp` save and clipboard copy
+- Plot export dialog with size presets/scales, background modes including transparency, scene toggles, export-only quality/supersampling, `.png`/`.bmp` save, clipboard copy, and post-save actions
 - Startup/manual update checks against GitHub releases with quick link to the releases page
 - Versioned binary metadata and installer packaging (`.msi` + setup `.exe`)
 

doc/run-guide.md

@@ -153,22 +153,25 @@ After launch:
 Use the sidebar **Export** section:
 
 1. Click **Open Export Dialog...**.
-2. Configure export options:
-   - output `Width` / `Height`
-   - **Lock Aspect Ratio** (or free width/height)
-   - **Color** vs **Grayscale**
-   - exported **Background Color** and **Background Opacity**
-   - include/exclude **Grid**, **Coordinates**, and **Wires / Wireframe**
-   - include/exclude **Envelope Box (3D)**
-   - use the **Preview** section to inspect export settings and click **Refresh Preview** after major changes if needed
-3. Click **Copy To Clipboard** to copy the exported plot image.
-4. Click **Save To File...** to save the exported plot as `.png` or `.bmp`.
+2. Configure export options in the tabbed settings pane:
+   - **Size**: choose the current viewport, a common preset, scale `1x`-`4x`, or custom `Width` / `Height`.
+   - **Appearance**: choose current, transparent, white, black, or custom background, and color vs grayscale output.
+   - **Scene**: include/exclude grid, coordinates, wires, envelope, and the axis triad.
+   - **Quality**: optionally override interactive quality for the export render only, including surface density, implicit-surface resolution, wire thickness scale, and supersampling.
+   - **Output**: choose `.png` or `.bmp` (PNG is the default) and optional post-save actions such as opening the image, showing it in Explorer, or copying the saved path.
+3. Use the right-side preview pane:
+   - click **Refresh Preview** for a manual preview render.
+   - enable **Auto Refresh** to refresh after a short debounce while changing settings.
+   - transparent exports are shown over a checkerboard background.
+4. Click **Copy To Clipboard** to copy the exported plot image.
+5. Click **Save To File...** to save the exported plot as `.png` or `.bmp`.
 
 Notes:
 
 - Export uses the current formulas and current view/zoom.
 - Background/grid/coordinate/wire/envelope export options are applied only to an offscreen export render pass (the on-screen plot is not used as the export source).
-- Export size is used as the offscreen render size (fallback screen-capture path may resample if offscreen export fails).
+- Export size is the final image size. Supersampling, when enabled, renders a larger offscreen buffer and downsamples to the selected output size.
+- Quality overrides are applied only to preview/export rendering and do not mutate the interactive plot quality settings.
 - Transparent backgrounds are supported in PNG export. Some viewers may display fully transparent pixels as black because the RGB value of fully transparent pixels is not visually meaningful.
 
 ## Version Details / Build Metadata

src/XpressFormula.Tests/ExportSettingsTests.cpp

@@ -0,0 +1,94 @@
+// ExportSettingsTests.cpp - Unit tests for export dialog helper logic.
+#include "CppUnitTest.h"
+#include "../XpressFormula/UI/ExportSettings.h"
+
+#include <cmath>
+
+using namespace Microsoft::VisualStudio::CppUnitTestFramework;
+using namespace XpressFormula::UI;
+
+namespace XpressFormulaTests {
+
+static void assertClose(double expected, double actual, double tolerance = 1e-6) {
+    Assert::IsTrue(std::abs(expected - actual) <= tolerance,
+        (std::to_wstring(expected) + L" != " + std::to_wstring(actual)).c_str());
+}
+
+TEST_CASE(ExportSize_ClampsDimensions) {
+    int width = 2;
+    int height = 20000;
+
+    validateExportSize(width, height);
+
+    Assert::AreEqual(kMinExportDimension, width);
+    Assert::AreEqual(kMaxExportDimension, height);
+}
+
+TEST_CASE(ExportSize_AspectLockedHeightPreservesRatio) {
+    const int height = aspectLockedHeight(1920, 1280, 720);
+
+    Assert::AreEqual(1080, height);
+}
+
+TEST_CASE(ExportSize_AspectLockedWidthPreservesRatio) {
+    const int width = aspectLockedWidth(1440, 1280, 720);
+
+    Assert::AreEqual(2560, width);
+}
+
+TEST_CASE(ExportSize_PresetsIncludeCurrentAndCustom) {
+    const auto& presets = exportSizePresets();
+
+    Assert::IsTrue(presets.front().useCurrentSize);
+    Assert::IsFalse(presets.front().custom);
+    Assert::IsTrue(presets.back().custom);
+    Assert::AreEqual(3840, presets[4].width);
+    Assert::AreEqual(2160, presets[4].height);
+}
+
+TEST_CASE(ExportSize_MemoryEstimateIncludesSupersampling) {
+    const auto oneX = estimateRgbaBufferBytes(1920, 1080, ExportSupersampling::Off);
+    const auto twoX = estimateRgbaBufferBytes(1920, 1080, ExportSupersampling::X2);
+
+    Assert::AreEqual(1920ull * 1080ull * 4ull, oneX);
+    Assert::AreEqual(oneX * 4ull, twoX);
+}
+
+TEST_CASE(ExportSize_EffectiveSupersamplingPreservesMaxDimension) {
+    const int scale = effectiveSupersamplingFactor(8192, 4096, ExportSupersampling::X4);
+
+    Assert::AreEqual(1, scale);
+}
+
+TEST_CASE(ExportSize_BytesToMiB) {
+    assertClose(1.0, bytesToMiB(1024ull * 1024ull));
+}
+
+TEST_CASE(ExportQuality_HighPresetMapsToExpectedValues) {
+    const auto quality = qualitySettingsForPreset(ExportQualityPreset::High);
+
+    Assert::AreEqual(ExportQualityPreset::High, quality.preset);
+    Assert::AreEqual(80, quality.surfaceResolution);
+    Assert::AreEqual(96, quality.implicitSurfaceResolution);
+    assertClose(1.25, quality.wireThicknessScale);
+    Assert::AreEqual(ExportSupersampling::X2, quality.supersampling);
+}
+
+TEST_CASE(ExportQuality_UltraUsesHighestSupersampling) {
+    const auto quality = qualitySettingsForPreset(ExportQualityPreset::Ultra);
+
+    Assert::AreEqual(ExportSupersampling::X4, quality.supersampling);
+    Assert::IsTrue(quality.surfaceResolution > qualitySettingsForPreset(ExportQualityPreset::High).surfaceResolution);
+}
+
+TEST_CASE(ExportQuality_CustomStartsFromNormalValues) {
+    const auto custom = qualitySettingsForPreset(ExportQualityPreset::Custom);
+    const auto normal = qualitySettingsForPreset(ExportQualityPreset::Normal);
+
+    Assert::AreEqual(ExportQualityPreset::Custom, custom.preset);
+    Assert::AreEqual(normal.surfaceResolution, custom.surfaceResolution);
+    Assert::AreEqual(normal.implicitSurfaceResolution, custom.implicitSurfaceResolution);
+    Assert::AreEqual(normal.supersampling, custom.supersampling);
+}
+
+} // namespace XpressFormulaTests

src/XpressFormula.Tests/XpressFormula.Tests.vcxproj

@@ -150,7 +150,8 @@
     <ClCompile Include="ViewTransformTests.cpp" />
     <ClCompile Include="FormulaEntryTests.cpp" />
     <ClCompile Include="UpdateVersionUtilsTests.cpp" />
+    <ClCompile Include="ExportSettingsTests.cpp" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets" />
-</Project>
+</Project>