[client] video: switch transport sources

Track primary and fallback video with source-specific generations, and
publish a source only after its first frame or software surface is
ready.

Route SPICE surfaces and cursors through the generic render queue. Keep
the current image across handoffs, and switch input only after the new
source has been presented.

Move fallback activation to its worker so display callbacks cannot
block or deadlock the render path.

client/src/render_queue.h

@@ -21,17 +21,40 @@
 #include "common/ll.h"
 #include "interface/renderer.h"
 
+#include <stdatomic.h>
+
+typedef enum RenderQueueSource
+{
+  RENDER_QUEUE_SOURCE_NONE,
+  RENDER_QUEUE_SOURCE_PRIMARY,
+  RENDER_QUEUE_SOURCE_FALLBACK,
+  RENDER_QUEUE_SOURCE_COUNT,
+}
+RenderQueueSource;
+
+typedef void (*RenderQueueSourceAppliedFn)(void * opaque,
+    RenderQueueSource source, uint64_t generation, uint64_t serial,
+    bool swSurface);
+typedef bool (*RenderQueueSourcePrepareFn)(void * opaque,
+    RenderQueueSource source, uint64_t generation, uint64_t serial);
+
 typedef struct
 {
+  RenderQueueSource source;
+  uint64_t          generation;
+  uint64_t          transitionSerial;
+
   enum
   {
-    SW_SURFACE_OP_CONFIGURE,
+    SW_SURFACE_OP_CONFIGURE_TRANSITION,
     SW_SURFACE_OP_DRAW_FILL,
     SW_SURFACE_OP_DRAW_BITMAP,
-    SW_SURFACE_OP_SHOW,
     SURFACE_OP_FORMAT,
     CURSOR_OP_STATE,
     CURSOR_OP_IMAGE,
+    CURSOR_OP_COLOR_TRANSFORM,
+    CURSOR_OP_WHITE_LEVEL,
+    SOURCE_OP_TRANSITION,
   }
   op;
 
@@ -41,7 +64,7 @@ typedef struct
     {
       int width, height;
     }
-    swSurfaceConfigure;
+    swSurfaceConfigureTransition;
 
     struct
     {
@@ -61,12 +84,6 @@ typedef struct
     }
     swSurfaceDrawBitmap;
 
-    struct
-    {
-      bool show;
-    }
-    swSurfaceShow;
-
     struct
     {
       LG_RendererFormat format;
@@ -93,6 +110,24 @@ typedef struct
       uint8_t         * data;
     }
     cursorImage;
+
+    struct
+    {
+      LGColorTransform * data;
+    }
+    cursorColorTransform;
+
+    struct
+    {
+      uint32_t value;
+    }
+    cursorWhiteLevel;
+
+    struct
+    {
+      bool swSurface;
+    }
+    sourceTransition;
   };
 }
 RenderCommand;
@@ -101,22 +136,48 @@ void renderQueue_init(void);
 void renderQueue_free(void);
 void renderQueue_clear(void);
 void renderQueue_process(void);
+void renderQueue_presented(void);
 
-void renderQueue_swSurfaceConfigure(int width, int height);
+void renderQueue_setSourceFns(RenderQueueSourcePrepareFn prepare,
+    RenderQueueSourceAppliedFn applied, void * opaque);
 
-void renderQueue_swSurfaceDrawFill(int x, int y, int width, int height,
+/* Starting a source lifecycle makes commands from its prior generation stale.
+ * After a successful render, call renderQueue_presented on the render thread
+ * to acknowledge the newest applied transition. */
+uint64_t renderQueue_sourceBegin(RenderQueueSource source);
+void renderQueue_sourceInvalidate(RenderQueueSource source,
+    uint64_t generation);
+void renderQueue_sourceClearCursor(RenderQueueSource source);
+uint64_t renderQueue_sourceTransition(RenderQueueSource source,
+    uint64_t generation, bool swSurface,
+    atomic_uint_least64_t * publishedSerial);
+
+uint64_t renderQueue_sourceSwSurfaceConfigureTransition(
+    RenderQueueSource source, uint64_t generation, int width, int height,
+    atomic_uint_least64_t * publishedSerial);
+
+void renderQueue_sourceSwSurfaceDrawFill(RenderQueueSource source,
+    uint64_t generation, int x, int y, int width, int height,
     uint32_t color);
 
-void renderQueue_swSurfaceDrawBitmap(int x, int y, int width, int height,
-    int stride, const void * data, bool topDown);
+void renderQueue_sourceSwSurfaceDrawBitmap(RenderQueueSource source,
+    uint64_t generation, int x, int y, int width, int height, int stride,
+    const void * data, bool topDown);
 
-void renderQueue_swSurfaceShow(bool show);
-
-void renderQueue_surfaceFormat(const LG_RendererFormat format,
+void renderQueue_sourceSurfaceFormat(RenderQueueSource source,
+    uint64_t generation, const LG_RendererFormat format,
     bool rendererSupportsNativeHDR);
 
-void renderQueue_cursorState(bool visible, int x, int y, int hx, int hy);
+void renderQueue_sourceCursorState(RenderQueueSource source,
+    uint64_t generation, bool visible, int x, int y, int hx, int hy);
 
-void renderQueue_cursorImage(LG_RendererCursor type,
-    int width, int height, int pitch,
-    uint8_t * data);
+/* Cursor payloads are copied before these calls return. */
+void renderQueue_sourceCursorImage(RenderQueueSource source,
+    uint64_t generation, LG_RendererCursor type,
+    int width, int height, int pitch, const void * data);
+
+void renderQueue_sourceCursorColorTransform(RenderQueueSource source,
+    uint64_t generation, const LGColorTransform * transform);
+
+void renderQueue_sourceCursorWhiteLevel(RenderQueueSource source,
+    uint64_t generation, uint32_t sdrWhiteLevel);