Add WGPUPresentMode_Undefined defaulting to Fifo (#333)

webgpu.h

@@ -517,30 +517,35 @@ typedef enum WGPUPowerPreference {
 typedef enum WGPUPresentMode {
     /**
      * `0x00000000`.
+     * Present mode is not specified. Use the default.
+     */
+    WGPUPresentMode_Undefined = 0x00000000,
+    /**
+     * `0x00000001`.
      * The presentation of the image to the user waits for the next vertical blanking period to update in a first-in, first-out manner.
      * Tearing cannot be observed and frame-loop will be limited to the display's refresh rate.
      * This is the only mode that's always available.
      */
-    WGPUPresentMode_Fifo = 0x00000000,
+    WGPUPresentMode_Fifo = 0x00000001,
     /**
-     * `0x00000001`.
+     * `0x00000002`.
      * The presentation of the image to the user tries to wait for the next vertical blanking period but may decide to not wait if a frame is presented late.
      * Tearing can sometimes be observed but late-frame don't produce a full-frame stutter in the presentation.
      * This is still a first-in, first-out mechanism so a frame-loop will be limited to the display's refresh rate.
      */
-    WGPUPresentMode_FifoRelaxed = 0x00000001,
+    WGPUPresentMode_FifoRelaxed = 0x00000002,
     /**
-     * `0x00000002`.
+     * `0x00000003`.
      * The presentation of the image to the user is updated immediately without waiting for a vertical blank.
      * Tearing can be observed but latency is minimized.
      */
-    WGPUPresentMode_Immediate = 0x00000002,
+    WGPUPresentMode_Immediate = 0x00000003,
     /**
-     * `0x00000003`.
+     * `0x00000004`.
      * The presentation of the image to the user waits for the next vertical blanking period to update to the latest provided image.
      * Tearing cannot be observed and a frame-loop is not limited to the display's refresh rate.
      */
-    WGPUPresentMode_Mailbox = 0x00000003,
+    WGPUPresentMode_Mailbox = 0x00000004,
     WGPUPresentMode_Force32 = 0x7FFFFFFF
 } WGPUPresentMode WGPU_ENUM_ATTRIBUTE;
 
@@ -1425,7 +1430,7 @@ typedef struct WGPUSurfaceConfiguration {
      */
     WGPUCompositeAlphaMode alphaMode;
     /**
-     * When and in which order the surface's frames will be shown on the screen.
+     * When and in which order the surface's frames will be shown on the screen. Defaults to @ref WGPUPresentMode_Fifo.
      */
     WGPUPresentMode presentMode;
 } WGPUSurfaceConfiguration WGPU_STRUCTURE_ATTRIBUTE;

webgpu.yml

@@ -598,6 +598,9 @@ enums:
   - name: present_mode
     doc: Describes when and in which order frames are presented on the screen when `::wgpuSurfacePresent` is called.
     entries:
+      - name: undefined
+        doc: |
+          Present mode is not specified. Use the default.
       - name: fifo
         doc: |
           The presentation of the image to the user waits for the next vertical blanking period to update in a first-in, first-out manner.
@@ -2725,7 +2728,7 @@ structs:
         doc: How the surface's frames will be composited on the screen.
         type: enum.composite_alpha_mode
       - name: present_mode
-        doc: When and in which order the surface's frames will be shown on the screen.
+        doc: When and in which order the surface's frames will be shown on the screen. Defaults to @ref WGPUPresentMode_Fifo.
         type: enum.present_mode
   - name: surface_descriptor
     doc: |