Add new python examples, also available embedded into UI

docs/python_api/examples/resource_usage.py

@@ -0,0 +1,54 @@
+# these imports are not strictly necessary, but are convenient
+import renderdoc
+import qrenderdoc
+
+# this is here to give autocomplete when editing the example
+# in VS Code where it doesn't know about this global
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    pyrenderdoc = qrenderdoc.CaptureContext()
+
+if not pyrenderdoc.IsCaptureLoaded():
+    filename = pyrenderdoc.Extensions().OpenFileName("Choose a capture", "", "*.rdc")
+
+    pyrenderdoc.LoadCapture(filename, renderdoc.ReplayOptions(), filename, False, True)
+
+pipe = pyrenderdoc.CurPipelineState()
+
+depth = pipe.GetDepthTarget().resource
+ib = pipe.GetIBuffer().resourceId
+
+if depth == renderdoc.ResourceId() or ib == renderdoc.ResourceId():
+    raise RuntimeError(
+        "Can't run example!\n"
+        "Current event doesn't use both index buffer and depth target"
+    )
+
+eid = pyrenderdoc.CurEvent()
+
+controller = pyrenderdoc.GetBlockingController()
+
+for name, id in [("Depth Target", depth), ("Index Buffer", ib)]:
+    usagelist = controller.GetUsage(id)
+
+    cur_usage = next(u for u in usagelist if u.eventId == eid).usage
+
+    prev_usages = [u for u in usagelist if u.eventId < eid and u.usage != cur_usage]
+    later_usages = [u for u in usagelist if u.eventId > eid and u.usage != cur_usage]
+
+    if len(prev_usages) == 0:
+        print(f"{name} {pyrenderdoc.GetResourceName(id)} was never used before {eid}!")
+    else:
+        print(
+            f"{name} {pyrenderdoc.GetResourceName(id)} was used as "
+            f"{str(prev_usages[-1].usage)} at {str(prev_usages[-1].eventId)}."
+        )
+
+    if len(later_usages) == 0:
+        print(f"{name} {pyrenderdoc.GetResourceName(id)} is never used after {eid}!")
+    else:
+        print(
+            f"{name} {pyrenderdoc.GetResourceName(id)} will be used as "
+            f"{str(later_usages[0].usage)} at {str(later_usages[0].eventId)}."
+        )