launcher: expose the Vulkan renderer

Cycle the renderer selector through Software, OpenGL, and Vulkan while retaining OpenGL-only option gating.

Co-authored-by: Martin Penkava <mpenkava1337@gmail.com>

docs/internal/upstream/martin-pr16-launcher-vulkan-option.md

@@ -0,0 +1,22 @@
+# Martin Penkava PR #16: launcher Vulkan option
+
+Last evaluated: 2026-07-14
+
+| Item | Value |
+| --- | --- |
+| Head repository/branch | `shaneomac1337/psxrecomp`, `smackdown2-fixes` (submitted as `mstan/psxrecomp` PR #16) |
+| Source commit | `d05d14bb11caafad2963abe824f249249a80cb11` |
+| Source author | Martin Penkava `<mpenkava1337@gmail.com>` |
+| Local base | `7085721afe338a03cb114321a3576cdff420b732` (`origin/master`) |
+| Local branch | `feat/pr16-launcher-vulkan-option-mpenkava` |
+
+## Included scope
+
+Adds Vulkan to the launcher's renderer cycle and label. The runtime already recognizes renderer value `2` as Vulkan; this exposes that existing backend through the graphical launcher while keeping OpenGL-only controls gated to renderer value `1`.
+
+## Deliberate exclusions
+
+- Vulkan backend correctness/performance changes are isolated on their own branches.
+- CRT presentation, diagnostics, and game-specific data are excluded.
+
+The source commit has no secondary co-author trailer; only Martin Penkava is credited in the local commit trailer.

runtime/launcher/launcher.cpp

@@ -96,7 +96,7 @@ public:
 
 // Mirror of the user-tunable settings, in the value shapes the RML binds to.
 struct LauncherModel {
-    int  renderer        = 0;  // 0=software, 1=opengl
+    int  renderer        = 0;  // 0=software, 1=opengl, 2=vulkan
     int  supersampling   = 1;  // 1..4
     bool antialiasing    = true;
     int  texture_filter  = 0;  // 0=nearest, 1=bilinear
@@ -382,7 +382,7 @@ int lang_index_for(const std::vector<psx_launcher::GameInfo::Language>& langs,
     return 0;   // unknown/first — the game's declared default sits at [0] by convention
 }
 
-const char* renderer_name(int v)  { return v == 1 ? "OpenGL" : "Software"; }
+const char* renderer_name(int v)  { return v == 2 ? "Vulkan" : v == 1 ? "OpenGL" : "Software"; }
 const char* texfilter_name(int v) { return v == 1 ? "Bilinear" : "Nearest"; }
 const char* crt_name(int v) {
     switch (v) {
@@ -962,7 +962,7 @@ Result run(SDL_Window* window, void* gl_context,
 
     c.BindEventCallback("cycle_renderer",
         [&m, handle](Rml::DataModelHandle, Rml::Event&, const Rml::VariantList&) mutable {
-            m.renderer ^= 1;
+            m.renderer = (m.renderer + 1) % 3;
             refresh_labels(m);
             handle.DirtyVariable("renderer_label");
             handle.DirtyVariable("opengl_renderer");

runtime/tests/test_launcher_vulkan_option.py

@@ -0,0 +1,8 @@
+#!/usr/bin/env python3
+from pathlib import Path
+
+source = (Path(__file__).parents[1] / "launcher" / "launcher.cpp").read_text()
+assert 'v == 2 ? "Vulkan"' in source
+assert "m.renderer = (m.renderer + 1) % 3" in source
+assert "m.renderer == 1" in source  # OpenGL-only controls remain OpenGL-only.
+print("Launcher Vulkan-option test passed")