Improve present info

vulkan-sys/src/structs/khr/presentinfokhr.rs

@@ -1,8 +1,14 @@
 use crate::prelude::*;
+use crate::structs::raw_to_slice;
 
 use std::os::raw::c_void;
 use std::ptr;
 
+pub struct PresentInfoSwapchain {
+    pub swapchain: VkSwapchainKHR,
+    pub index: u32,
+}
+
 #[repr(C)]
 #[derive(Debug)]
 pub struct VkPresentInfoKHR {
@@ -41,4 +47,38 @@ impl VkPresentInfoKHR {
             },
         }
     }
+
+    pub fn wait_semaphores(&self) -> &[VkSemaphore] {
+        if self.waitSemaphoreCount == 0 {
+            &[]
+        } else {
+            raw_to_slice(self.pWaitSemaphores, self.waitSemaphoreCount)
+        }
+    }
+
+    pub fn swapchain_info(&self) -> Vec<PresentInfoSwapchain> {
+        let mut swapchain_infos = Vec::with_capacity(self.swapchainCount as usize);
+
+        if self.swapchainCount != 0 {
+            let swapchains = raw_to_slice(self.pSwapchains, self.swapchainCount);
+            let indices = raw_to_slice(self.pImageIndices, self.swapchainCount);
+
+            for i in 0..(self.swapchainCount as usize) {
+                swapchain_infos.push(PresentInfoSwapchain {
+                    swapchain: swapchains[i],
+                    index: indices[i],
+                });
+            }
+        }
+
+        swapchain_infos
+    }
+
+    pub fn results(&self) -> &[VkResult] {
+        if self.waitSemaphoreCount == 0 || self.pResults != ptr::null_mut() {
+            &[]
+        } else {
+            raw_to_slice(self.pResults, self.waitSemaphoreCount)
+        }
+    }
 }