[OpenGL] Set swap interval (vsync) with `gl_vsync` param

src/gl/gl.h

@@ -10,6 +10,7 @@ void glXSwapBuffers(void*, void*);
 void glXSwapIntervalEXT(void*, void*, int);
 int glXSwapIntervalSGI(int);
 int glXSwapIntervalMESA(unsigned int);
+int glXGetSwapIntervalMESA(void);
 bool glXMakeCurrent(void*, void*, void*);
 
 void* glXGetProcAddress(const unsigned char*);

src/gl/inject.cpp

@@ -208,18 +208,73 @@ EXPORT_C_(void) glXSwapBuffers(void* dpy, void* drawable) {
     }
 }
 
+EXPORT_C_(void) glXSwapIntervalEXT(void *dpy, void *draw, int interval) {
+#ifndef NDEBUG
+    std::cerr << __func__ << ": " << interval << std::endl;
+#endif
+
+    gl.Load();
+    if (params.gl_vsync >= 0)
+        interval = params.gl_vsync;
+    gl.glXSwapIntervalEXT(dpy, draw, interval);
+}
+
+EXPORT_C_(int) glXSwapIntervalSGI(int interval) {
+#ifndef NDEBUG
+    std::cerr << __func__ << ": " << interval << std::endl;
+#endif
+    gl.Load();
+    if (params.gl_vsync >= 0)
+        interval = params.gl_vsync;
+    return gl.glXSwapIntervalSGI(interval);
+}
+
+EXPORT_C_(int) glXSwapIntervalMESA(unsigned int interval) {
+#ifndef NDEBUG
+    std::cerr << __func__ << ": " << interval << std::endl;
+#endif
+    gl.Load();
+    if (params.gl_vsync >= 0)
+        interval = (unsigned int)params.gl_vsync;
+    return gl.glXSwapIntervalMESA(interval);
+}
+
+EXPORT_C_(int) glXGetSwapIntervalMESA() {
+    gl.Load();
+    static bool first_call = true;
+    int interval = gl.glXGetSwapIntervalMESA();
+
+    if (first_call) {
+        first_call = false;
+        if (params.gl_vsync >= 0) {
+            interval = params.gl_vsync;
+            gl.glXSwapIntervalMESA(interval);
+        }
+    }
+
+#ifndef NDEBUG
+    std::cerr << __func__ << ": " << interval << std::endl;
+#endif
+    return interval;
+}
+
 struct func_ptr {
    const char *name;
    void *ptr;
 };
 
-static std::array<const func_ptr, 5> name_to_funcptr_map = {{
+static std::array<const func_ptr, 9> name_to_funcptr_map = {{
 #define ADD_HOOK(fn) { #fn, (void *) fn }
    ADD_HOOK(glXGetProcAddress),
    ADD_HOOK(glXGetProcAddressARB),
    ADD_HOOK(glXCreateContext),
    ADD_HOOK(glXMakeCurrent),
    ADD_HOOK(glXSwapBuffers),
+
+   ADD_HOOK(glXSwapIntervalEXT),
+   ADD_HOOK(glXSwapIntervalSGI),
+   ADD_HOOK(glXSwapIntervalMESA),
+   ADD_HOOK(glXGetSwapIntervalMESA),
 #undef ADD_HOOK
 }};
 

src/loaders/loader_gl.cpp

@@ -71,6 +71,10 @@ bool gl_loader::Load(bool egl_only) {
       reinterpret_cast<decltype(this->glXSwapIntervalMESA)>(
           glXGetProcAddress((const unsigned char *)"glXSwapIntervalMESA"));
 
+  glXGetSwapIntervalMESA =
+      reinterpret_cast<decltype(this->glXGetSwapIntervalMESA)>(
+          glXGetProcAddress((const unsigned char *)"glXGetSwapIntervalMESA"));
+
   glXMakeCurrent =
       reinterpret_cast<decltype(this->glXMakeCurrent)>(
           glXGetProcAddress((const unsigned char *)"glXMakeCurrent"));

src/loaders/loader_gl.h

@@ -20,6 +20,7 @@ class gl_loader {
   decltype(&::glXSwapIntervalEXT) glXSwapIntervalEXT;
   decltype(&::glXSwapIntervalSGI) glXSwapIntervalSGI;
   decltype(&::glXSwapIntervalMESA) glXSwapIntervalMESA;
+  decltype(&::glXGetSwapIntervalMESA) glXGetSwapIntervalMESA;
   decltype(&::glXMakeCurrent) glXMakeCurrent;
 
   decltype(&::glClipControl) glClipControl;

src/overlay_params.cpp

@@ -151,6 +151,7 @@ parse_str(const char *str)
 #define parse_width(s) parse_unsigned(s)
 #define parse_height(s) parse_unsigned(s)
 #define parse_vsync(s) parse_unsigned(s)
+#define parse_gl_vsync(s) parse_unsigned(s)
 #define parse_offset_x(s) parse_unsigned(s)
 #define parse_offset_y(s) parse_unsigned(s)
 #define parse_time_format(s) parse_str(s)
@@ -307,6 +308,7 @@ parse_overlay_config(struct overlay_params *params,
    params->refresh_config = XK_F4;
    params->fps_limit = 0;
    params->vsync = -1;
+   params->gl_vsync = -1;
    params->crosshair_size = 30;
    params->offset_x = 0;
    params->offset_y = 0;

src/overlay_params.h

@@ -71,6 +71,7 @@ extern "C" {
    OVERLAY_PARAM_CUSTOM(control)                     \
    OVERLAY_PARAM_CUSTOM(fps_limit)                   \
    OVERLAY_PARAM_CUSTOM(vsync)                       \
+   OVERLAY_PARAM_CUSTOM(gl_vsync)                    \
    OVERLAY_PARAM_CUSTOM(font_size)                   \
    OVERLAY_PARAM_CUSTOM(toggle_hud)                  \
    OVERLAY_PARAM_CUSTOM(toggle_logging)              \
@@ -127,6 +128,7 @@ struct overlay_params {
    unsigned height;
    int offset_x, offset_y;
    unsigned vsync;
+   int gl_vsync;
    unsigned crosshair_color, cpu_color, gpu_color, vram_color, ram_color, engine_color, io_color, frametime_color, background_color, text_color;
    unsigned tableCols;
    float font_size;