solvespace · sbarber-dsi · Mar 25, 2026 · Mar 25, 2026 · Mar 27, 2026
diff --git a/.github/scripts/build-ubuntu-gtk4.sh b/.github/scripts/build-ubuntu-gtk4.sh
@@ -0,0 +1,12 @@
+#!/bin/sh -xe
+
+mkdir build
+cd build
+cmake \
+  -DCMAKE_BUILD_TYPE="RelWithDebInfo" \
+  -DENABLE_OPENMP="ON" \
+  -DENABLE_SANITIZERS="ON" \
+  -DUSE_GTK4_GUI="ON" \
+  ..
+make -j$(nproc) VERBOSE=1
+make test_solvespace
diff --git a/.github/scripts/install-ubuntu-gtk4.sh b/.github/scripts/install-ubuntu-gtk4.sh
@@ -0,0 +1,10 @@
+#!/bin/sh -xe
+
+sudo apt-get update -qq
+
+sudo apt-get install -q -y \
+  zlib1g-dev libpng-dev libcairo2-dev libfreetype6-dev libjson-c-dev \
+  libfontconfig1-dev libgtkmm-4.0-dev libgl-dev \
+  libglu-dev libspnav-dev
+
+git submodule update --init extlib/libdxfrw extlib/mimalloc extlib/eigen
diff --git a/.github/workflows/cd.yml b/.github/workflows/cd.yml
@@ -30,6 +30,17 @@ jobs:
     - name: Build & Test
       run: .github/scripts/build-ubuntu.sh
 
+  test_ubuntu_gtk4:
+    needs: [cancel_previous_runs]
+    runs-on: ubuntu-latest
+    name: Test Ubuntu (GTK4)
+    steps:
+    - uses: actions/checkout@v4
+    - name: Install Dependencies
+      run: .github/scripts/install-ubuntu-gtk4.sh
+    - name: Build & Test
+      run: .github/scripts/build-ubuntu-gtk4.sh
+
   test_windows:
     needs: [cancel_previous_runs]
     runs-on: windows-2022
@@ -55,7 +66,7 @@ jobs:
       run: .github/scripts/build-macos.sh debug arm64 && .github/scripts/build-macos.sh debug x86_64
 
   build_release_windows_x86:
-    needs: [test_ubuntu, test_windows, test_macos]
+    needs: [test_ubuntu, test_ubuntu_gtk4, test_windows, test_macos]
     name: Build Release Windows x86
     runs-on: windows-2022
     steps:
@@ -73,7 +84,7 @@ jobs:
           path: build/bin/RelWithDebInfo/solvespace_single_core_x86.exe
 
   build_release_windows_openmp_x86:
-    needs: [test_ubuntu, test_windows, test_macos]
+    needs: [test_ubuntu, test_ubuntu_gtk4, test_windows, test_macos]
     name: Build Release Windows (OpenMP) x86
     runs-on: windows-2022
     steps:
@@ -91,7 +102,7 @@ jobs:
           path: build/bin/RelWithDebInfo/solvespace_x86.exe
 
   build_release_windows_x64:
-    needs: [test_ubuntu, test_windows, test_macos]
+    needs: [test_ubuntu, test_ubuntu_gtk4, test_windows, test_macos]
     name: Build Release Windows x64
     runs-on: windows-2022
     steps:
@@ -109,7 +120,7 @@ jobs:
           path: build/bin/RelWithDebInfo/solvespace_single_core_x64.exe
 
   build_release_windows_openmp_x64:
-    needs: [test_ubuntu, test_windows, test_macos]
+    needs: [test_ubuntu, test_ubuntu_gtk4, test_windows, test_macos]
     name: Build Release Windows (OpenMP) x64
     runs-on: windows-2022
     steps:
@@ -127,7 +138,7 @@ jobs:
           path: build/bin/RelWithDebInfo/solvespace_x64.exe
 
   build_release_macos:
-    needs: [test_ubuntu, test_windows, test_macos]
+    needs: [test_ubuntu, test_ubuntu_gtk4, test_windows, test_macos]
     name: Build Release macOS
     runs-on: macos-latest
     steps:
@@ -151,7 +162,7 @@ jobs:
         path: build/bin/SolveSpace.dmg
 
   build_release_web:
-    needs: [test_ubuntu, test_windows, test_macos]
+    needs: [test_ubuntu, test_ubuntu_gtk4, test_windows, test_macos]
     name: Build Release Web
     runs-on: ubuntu-latest
     steps:

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
@@ -21,6 +21,16 @@ jobs:
       - name: Build & Test
         run: .github/scripts/build-ubuntu.sh
 
+  test_ubuntu_gtk4:
+    runs-on: ubuntu-latest
+    name: Test Ubuntu (GTK4)
+    steps:
+    - uses: actions/checkout@v4
+    - name: Install Dependencies
+      run: .github/scripts/install-ubuntu-gtk4.sh
+    - name: Build & Test
+      run: .github/scripts/build-ubuntu-gtk4.sh
+
   test_windows:
     runs-on: windows-2022
     name: Test Windows

diff --git a/AGENTS.md b/AGENTS.md
@@ -0,0 +1,89 @@
+# SolveSpace — Agent Guidelines
+
+## Project Overview
+
+SolveSpace is a parametric 2D/3D CAD application written in C++11. It consists of a
+**portable core** (everything outside `src/platform/`) and **platform-specific UI** code
+(`src/platform/`). Licensed under GPLv3+.
+
+## Building
+
+```sh
+mkdir build && cd build
+cmake .. -DCMAKE_BUILD_TYPE=Debug
+make -j$(nproc)
+```
+
+Run tests:
+```sh
+make test_solvespace
+# or directly:
+./build/test/solvespace-testsuite
+```
+
+The test suite links against `solvespace-headless` (no GUI). Tests live in `test/`
+organized by category (constraint, request, group, core, analysis).
+
+## Architecture
+
+| Directory | Purpose |
+|-----------|---------|
+| `src/` | Portable core: geometric kernel, constraint solver, file I/O, UI logic |
+| `src/platform/` | Platform abstraction layer (`gui.h`, `platform.h`) and backends |
+| `src/platform/gui*.cpp` | GUI backends: `guigtk.cpp` (GTK 3), `guiqt.cpp` (Qt), `guiwin.cpp` (Win32), `guimac.mm` (Cocoa), `guihtml.cpp` (Emscripten), `guinone.cpp` (headless) |
+| `src/render/` | Rendering backends (OpenGL 1/3, Cairo, 2D export) |
+| `src/slvs/` | C API for the constraint solver library |
+| `src/srf/` | Surface/NURBS code |
+| `include/` | Public header for the solver library (`slvs.h`) |
+| `extlib/` | Vendored third-party libraries (built as CMake subprojects) |
+| `res/` | Resources: icons, locales, shaders, fonts |
+| `test/` | Test suite (branch-coverage focused) |
+| `exposed/` | Additional language bindings |
+
+## Coding Conventions
+
+### Style
+- **4-space indent**, no tabs, no trailing whitespace, 100-column wrap.
+- Braces on same line as declaration/control flow (`Attach` style).
+- Braces required on all control flow bodies, even single-statement.
+- No space after `if`, `while`, `for` — write `if(cond)` not `if (cond)`.
+- camelCase variables (`exampleVar`), PascalCase functions (`ExampleFunction`).
+- Apply `.clang-format` via `git clang-format` before committing.
+
+### C++ Usage
+- **C++11 only** — do not use C++14/17/20 features.
+- **No exceptions** — they interfere with branch-coverage measurement.
+- **No operator overloading** — use named methods (e.g. `Plus`, `Minus`).
+- **All members are public** — no access specifiers for implementation hiding.
+- **No constructors for initialization** — use aggregate init `Foo foo = {};`.
+- Output parameters are passed by pointer (`Vector *out`), never by reference.
+- Use `ssassert(cond, "message")` instead of `assert()` — it is always enabled.
+- Use `ssprintf()` for string formatting (remember `.c_str()` for std::string args).
+- Use `ssfopen()` / `ssremove()` for filesystem access (UTF-8 safe).
+- Strings are always UTF-8 internally.
+
+### Platform Code
+- Everything outside `src/platform/` must be portable standard C++11.
+- Platform interaction goes through `src/platform/platform.h` and `src/platform/gui.h`.
+- When adding a new platform backend, implement the abstract interfaces in `gui.h`
+  (`Window`, `Menu`, `MenuBar`, `MenuItem`, `Timer`, `Settings`, `MessageDialog`,
+  `FileDialog`) plus the free functions (`InitGui`, `RunGui`, `ExitGui`, etc.).
+
+### Libraries
+- External libraries must be portable, includable as CMake subprojects, and use a
+  license less restrictive than GPL (BSD/MIT, Apache2, MPL).
+- STL I/O streams are **not used** — SolveSpace has its own file I/O.
+- Check `extlib/` and `CMakeLists.txt` for available dependencies before adding new ones.
+
+## Testing
+
+- Tests use the headless build (`solvespace-headless`).
+- Test harness is in `test/harness.h` / `test/harness.cpp`.
+- Tests compare against reference `.slvs` files and expected output.
+- Branch coverage is tracked — avoid patterns that add untestable branches.
+- `ssassert` and `switch` are excluded from coverage metrics.
+
+## Plans
+
+Migration/implementation plans are stored in `plans/`. Read them before starting
+related work.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -60,6 +60,8 @@ set(ENABLE_GUI        ON CACHE BOOL
     "Whether the graphical interface is enabled")
 set(USE_QT_GUI        OFF CACHE BOOL
     "Whether the Qt library used to build graphical interface")
+set(USE_GTK4_GUI      OFF CACHE BOOL
+    "Whether GTK 4 is used instead of GTK 3 for the graphical interface")
 set(ENABLE_CLI        ${INCLUDE_NATIVE_COMPONENTS} CACHE BOOL
     "Whether the command line interface is enabled")
 set(ENABLE_TESTS      ${INCLUDE_NATIVE_COMPONENTS} CACHE BOOL
@@ -76,6 +78,15 @@ option(FORCE_VENDORED_Eigen3
     "Whether we should use our bundled Eigen even in the presence of a system copy"
     OFF)
 
+if(USE_QT_GUI AND USE_GTK4_GUI)
+    message(FATAL_ERROR "USE_QT_GUI and USE_GTK4_GUI are mutually exclusive")
+endif()
+
+# gtkmm-4.0 requires C++17; override the default C++11 standard.
+if(USE_GTK4_GUI)
+    set(CMAKE_CXX_STANDARD 17)
+endif()
+
 set(OPENGL 3 CACHE STRING "OpenGL version to use (one of: 1 3)")
 
 set(EXECUTABLE_OUTPUT_PATH ${CMAKE_BINARY_DIR}/bin)
@@ -340,7 +351,7 @@ if(ENABLE_GUI OR ENABLE_CLI)
         find_package(ZLIB REQUIRED)
         find_package(PNG REQUIRED)
         find_package(Freetype REQUIRED)
-        if (NOT USE_QT_GUI OR ENABLE_CLI OR ENABLE_TESTS)
+        if (NOT USE_QT_GUI OR USE_GTK4_GUI OR ENABLE_CLI OR ENABLE_TESTS)
             find_package(Cairo REQUIRED)
         endif()
     endif()
@@ -383,7 +394,10 @@ if(ENABLE_GUI)
         find_package(OpenGL REQUIRED)
         find_package(SpaceWare)
         pkg_check_modules(FONTCONFIG REQUIRED fontconfig)
-        if (NOT USE_QT_GUI)
+        if(USE_GTK4_GUI)
+            pkg_check_modules(JSONC REQUIRED json-c)
+            pkg_check_modules(GTKMM REQUIRED gtkmm-4.0>=4.10)
+        elseif(NOT USE_QT_GUI)
             pkg_check_modules(JSONC REQUIRED json-c)
             pkg_check_modules(GTKMM REQUIRED gtkmm-3.0>=3.18 pangomm-1.4 x11)
         endif()

diff --git a/extlib/si/spwmacro.h b/extlib/si/spwmacro.h
@@ -1,11 +1,7 @@
 /*----------------------------------------------------------------------
  *  spwmacro.h -- cpp macros we ALWAYS use.
  *
-<<<<<<< spwmacro.h
  *  $Id: spwmacro.h,v 1.3 2001/01/16 01:18:40 HJin Exp $
-=======
- *  $Id: spwmacro.h,v 1.3 2001/01/16 01:18:40 HJin Exp $
->>>>>>> 1.1.1.1.4.1
  *
  *   We always seem to use the same macros.
  *   This is the place we define them.

diff --git a/makefile b/makefile
@@ -0,0 +1,54 @@
+all: # Default target
+
+.SUFFIXES: # Disables built-in rules
+.ONESHELL:
+
+# Parameters
+DEB_PACKAGES_COMMON=git \
+	build-essential \
+	cmake \
+	zlib1g-dev \
+	libpng-dev \
+	libcairo2-dev \
+	libfreetype6-dev \
+	libjson-c-dev \
+	libfontconfig1-dev \
+	libgl-dev \
+	libglu-dev \
+	libspnav-dev
+
+DEB_PACKAGES_GTK3=libgtkmm-3.0-dev \
+	libpangomm-1.4-dev
+
+DEB_PACKAGES_GTK4=libgtkmm-4.0-dev
+
+DEB_PACKAGES_QT=qt6-base-dev
+
+
+# Dependencies
+#all: build-gtk3/bin/solvespace
+all: build-gtk4/bin/solvespace
+#all: build-qt/bin/solvespace
+build-gtk3/Makefile: CMAKE_OPT=-DENABLE_GUI=ON
+build-gtk4/Makefile: CMAKE_OPT=-DENABLE_GUI=ON -DUSE_GTK4_GUI=ON
+build-qt/Makefile: CMAKE_OPT=-DENABLE_GUI=ON -DUSE_QT_GUI=ON
+
+
+# Recipes
+build-%/Makefile:
+	mkdir -p $(@D)
+	cd $(@D)
+	cmake .. $(CMAKE_OPT)
+
+build-%/bin/solvespace: build-%/Makefile
+	make -C build-$* -kj
+
+
+# Commands
+.PHONY: tools
+tools:
+	sudo apt install -y $(DEB_PACKAGES_COMMON) $(DEB_PACKAGES_GTK3) $(DEB_PACKAGES_GTK4) $(DEB_PACKAGES_QT)
+
+.PHONY: clean
+clean:
+	rm -rf build-*