Added vsync option

src/overlay.cpp

@@ -26,6 +26,7 @@
 #include <assert.h>
 #include <thread>
 #include <chrono>
+#include <unordered_map>
 
 #include <vulkan/vulkan.h>
 #include <vulkan/vk_layer.h>
@@ -2123,11 +2124,19 @@ static VkResult overlay_CreateSwapchainKHR(
     VkSwapchainKHR*                             pSwapchain)
 {
    struct device_data *device_data = FIND(struct device_data, device);
+   std::array<VkPresentModeKHR, 4> modes = {VK_PRESENT_MODE_FIFO_RELAXED_KHR,
+           VK_PRESENT_MODE_IMMEDIATE_KHR,
+           VK_PRESENT_MODE_MAILBOX_KHR,
+           VK_PRESENT_MODE_FIFO_KHR};
+
+   if (device_data->instance->params.vsync < 4)
+      const_cast<VkSwapchainCreateInfoKHR*> (pCreateInfo)->presentMode = modes[device_data->instance->params.vsync];
+
    VkResult result = device_data->vtable.CreateSwapchainKHR(device, pCreateInfo, pAllocator, pSwapchain);
    if (result != VK_SUCCESS) return result;
-
    struct swapchain_data *swapchain_data = new_swapchain_data(*pSwapchain, device_data);
    setup_swapchain_data(swapchain_data, pCreateInfo);
+   
    return result;
 }
 
@@ -2552,6 +2561,7 @@ static VkResult overlay_CreateInstance(
 {
    VkLayerInstanceCreateInfo *chain_info =
       get_instance_chain_info(pCreateInfo, VK_LAYER_LINK_INFO);
+      
 
    const char* pEngineName = pCreateInfo->pApplicationInfo->pEngineName;
    if (pEngineName)

src/overlay_params.c

@@ -85,6 +85,12 @@ parse_fps_limit(const char *str)
    return strtol(str, NULL, 0);
 }
 
+static uint32_t
+parse_vsync(const char *str)
+{
+   return strtol(str, NULL, 0);
+}
+
 static bool
 parse_no_display(const char *str)
 {
@@ -99,6 +105,7 @@ parse_unsigned(const char *str)
 
 #define parse_width(s) parse_unsigned(s)
 #define parse_height(s) parse_unsigned(s)
+#define parse_vsync(s) parse_unsigned(s)
 
 static bool
 parse_help(const char *str)
@@ -190,6 +197,7 @@ parse_overlay_env(struct overlay_params *params,
    params->height = 140;
    params->control = -1;
    params->fps_limit = 0;
+   params->vsync = -1;
 
    if (!env)
       return;

src/overlay_params.h

@@ -53,6 +53,7 @@ extern "C" {
    OVERLAY_PARAM_CUSTOM(no_display)                  \
    OVERLAY_PARAM_CUSTOM(control)                     \
    OVERLAY_PARAM_CUSTOM(fps_limit)                   \
+   OVERLAY_PARAM_CUSTOM(vsync)                       \
    OVERLAY_PARAM_CUSTOM(font_size)                   \
    OVERLAY_PARAM_CUSTOM(help)
 
@@ -83,6 +84,7 @@ struct overlay_params {
    bool no_display;
    unsigned width;
    unsigned height;
+   unsigned vsync;
    float font_size;
 };