fix Windows builds under MSYS2

- Use Windows executable-path APIs when returning to the song menu
- Add an SDL-based OpenGL compatibility helper for glActiveTexture so
  it resolves at runtime instead of linking against the OpenGL 1.1-only
  Windows import library

README.md

@@ -1,7 +1,5 @@
 # OpenRoller
 
-meow
-
 OpenRoller is an experimental rhythm-game runtime for desktop Linux and Sony
 PSP. It reconstructs compatible playback from independently researched stage
 formats and user-provided data.

apps/desktop/include/openroller/desktop/GlCompat.hpp

@@ -0,0 +1,10 @@
+#pragma once
+
+#include "vectorail/core/gl_loader.hpp"
+
+inline void ActivateTexture(GLenum texture) {
+    using ActiveTextureProc = void(APIENTRY *)(GLenum);
+    static const auto activeTexture = reinterpret_cast<ActiveTextureProc>(
+        SDL_GL_GetProcAddress("glActiveTexture"));
+    if (activeTexture) activeTexture(texture);
+}

apps/desktop/src/ServiceMenu.cpp

@@ -1,6 +1,7 @@
 #include "openroller/desktop/ServiceMenu.hpp"
 
 #include "openroller/desktop/CabinetBackend.hpp"
+#include "openroller/desktop/GlCompat.hpp"
 #include "vectorail/core/Shader.hpp"
 #include "vectorail/core/gl_loader.hpp"
 
@@ -109,7 +110,7 @@ public:
             shader_.setBool("uUseTexture", true);
             shader_.setBool("uUseGradient", false);
             shader_.setVec4("uColor", color);
-            glActiveTexture(GL_TEXTURE0);
+            ActivateTexture(GL_TEXTURE0);
             glBindTexture(GL_TEXTURE_2D, activeTexture);
             glBindVertexArray(vao_);
             glBindBuffer(GL_ARRAY_BUFFER, vbo_);

apps/desktop/src/main.cpp

@@ -14,8 +14,13 @@
 #include <filesystem>
 #include <limits>
 #include <string_view>
+#ifdef _WIN32
+#include <windows.h>
+#include <process.h>
+#else
 #include <limits.h>
 #include <unistd.h>
+#endif
 #include <glm/glm.hpp>
 #include <glm/gtc/matrix_transform.hpp>
 #include <glm/gtc/quaternion.hpp>
@@ -23,6 +28,7 @@
 #include "vectorail/core/Shader.hpp"
 #include "openroller/desktop/LevelLoader.hpp"
 #include "openroller/desktop/AudioManager.hpp"
+#include "openroller/desktop/GlCompat.hpp"
 #include "vectorail/core/DdsTexture.hpp"
 #include "gc/GcTargetEffect.hpp"
 #include "vectorail/core/PngTexture.hpp"
@@ -2077,7 +2083,7 @@ int main(int argc, char* argv[]) {
             noteShader.use();
             noteShader.setMat4("uProjection", proj);
             noteShader.setInt("uTexture", 0);
-            glActiveTexture(GL_TEXTURE0);
+            ActivateTexture(GL_TEXTURE0);
             glBindVertexArray(noteSpriteVAO);
             for (const MarkerDraw& marker : markerDraws) {
                 if (marker.effectId <= 0 || marker.uvRecordBase < 0) continue;
@@ -2169,7 +2175,7 @@ int main(int argc, char* argv[]) {
             noteShader.use();
             noteShader.setMat4("uProjection", proj);
             noteShader.setInt("uTexture", 0);
-            glActiveTexture(GL_TEXTURE0);
+            ActivateTexture(GL_TEXTURE0);
             glBindVertexArray(noteSpriteVAO);
             glDepthMask(GL_FALSE);
             glBlendFunc(GL_SRC_ALPHA, GL_ONE);
@@ -2250,7 +2256,7 @@ int main(int argc, char* argv[]) {
                 glm::ortho(0.0f, static_cast<float>(kGameWidth),
                            static_cast<float>(kGameHeight), 0.0f, -1.0f, 1.0f));
             noteShader.setInt("uTexture", 0);
-            glActiveTexture(GL_TEXTURE0);
+            ActivateTexture(GL_TEXTURE0);
             glBindTexture(GL_TEXTURE_2D, helperAtlas.id);
             glBindVertexArray(noteSpriteVAO);
             const glm::mat4 helperRoot = glm::scale(
@@ -2328,6 +2334,25 @@ int main(int argc, char* argv[]) {
     }
     for (SDL_Gamepad* gamepad : gamepads) SDL_CloseGamepad(gamepad);
     if (chartCompleted && !gcRoot.empty()) {
+#ifdef _WIN32
+        char executable[MAX_PATH]{};
+        const DWORD length = GetModuleFileNameA(nullptr, executable, sizeof(executable));
+        if (length > 0 && length < sizeof(executable)) {
+            const std::string root = gcRoot.string();
+            if (gameplayItem == GcGameplayItem::Mirror) {
+                _execl(executable, executable, "--item", "mirror",
+                       "--menu", root.c_str(), static_cast<char*>(nullptr));
+            } else if (gameplayItem == GcGameplayItem::Reverse) {
+                _execl(executable, executable, "--item", "reverse",
+                       "--menu", root.c_str(), static_cast<char*>(nullptr));
+            } else {
+                _execl(executable, executable, "--menu", root.c_str(),
+                       static_cast<char*>(nullptr));
+            }
+            std::cerr << "Could not return to song menu: "
+                      << std::strerror(errno) << std::endl;
+        }
+#else
         char executable[PATH_MAX]{};
         const ssize_t length = readlink(
             "/proc/self/exe", executable, sizeof(executable) - 1);
@@ -2347,6 +2372,7 @@ int main(int argc, char* argv[]) {
             std::cerr << "Could not return to song menu: "
                       << std::strerror(errno) << std::endl;
         }
+#endif
     }
     return 0;
 }