Add replay API note that top-left co-ordinates are expected

* This is only relevant on GL where co-ordinates are bottom-left, so translation
  from e.g. viewports or scissors are required.

renderdoc/api/replay/control_types.h

@@ -172,6 +172,12 @@ Describes how to render a texture preview of an image. Describes the zoom and pa
 texture when rendering on a particular output, as well as the modification and selection of a
 particular subresource (such as array slice, mip or multi-sampled sample).
 
+.. note::
+  X and Y co-ordinates are always considered to be top-left, even on GL, for consistency between
+  APIs and preventing the need for API-specific code in most cases. This means if co-ordinates are
+  fetched from e.g. viewport or scissor data or other GL pipeline state which is perhaps in
+  bottom-left co-ordinates, care must be taken to translate them.
+
 .. data:: ResolveSamples
 
   Value for :data:`sampleIdx` if the samples should be averaged.

renderdoc/api/replay/renderdoc_replay.h

@@ -785,6 +785,12 @@ Should only be called for texture outputs.
 
 Should only be called for texture outputs.
 
+.. note::
+  X and Y co-ordinates are always considered to be top-left, even on GL, for consistency between
+  APIs and preventing the need for API-specific code in most cases. This means if co-ordinates are
+  fetched from e.g. viewport or scissor data or other GL pipeline state which is perhaps in
+  bottom-left co-ordinates, care must be taken to translate them.
+
 :param ResourceId textureId: The texture to pick the pixel from.
 :param bool customShader: Whether to apply the configured custom shader.
 :param int x: The x co-ordinate to pick from.
@@ -801,6 +807,12 @@ Should only be called for texture outputs.
   DOCUMENT(R"(Retrieves the vertex and instance that is under the cursor location, when viewed
 relative to the current window with the current mesh display configuration.
 
+.. note::
+  X and Y co-ordinates are always considered to be top-left, even on GL, for consistency between
+  APIs and preventing the need for API-specific code in most cases. This means if co-ordinates are
+  fetched from e.g. viewport or scissor data or other GL pipeline state which is perhaps in
+  bottom-left co-ordinates, care must be taken to translate them.
+
 Should only be called for mesh outputs.
 
 :param int eventId: The event ID to pick at.
@@ -1163,6 +1175,12 @@ only ever have one result (only one entry point per shader).
 
   DOCUMENT(R"(Retrieve the history of modifications to the selected pixel on the selected texture.
 
+.. note::
+  X and Y co-ordinates are always considered to be top-left, even on GL, for consistency between
+  APIs and preventing the need for API-specific code in most cases. This means if co-ordinates are
+  fetched from e.g. viewport or scissor data or other GL pipeline state which is perhaps in
+  bottom-left co-ordinates, care must be taken to translate them.
+
 :param ResourceId texture: The texture to search for modifications.
 :param int x: The x co-ordinate.
 :param int y: The y co-ordinate.
@@ -1194,6 +1212,12 @@ only ever have one result (only one entry point per shader).
 
   DOCUMENT(R"(Retrieve a debugging trace from running a pixel shader.
 
+.. note::
+  X and Y co-ordinates are always considered to be top-left, even on GL, for consistency between
+  APIs and preventing the need for API-specific code in most cases. This means if co-ordinates are
+  fetched from e.g. viewport or scissor data or other GL pipeline state which is perhaps in
+  bottom-left co-ordinates, care must be taken to translate them.
+
 :param int x: The x co-ordinate.
 :param int y: The y co-ordinate.
 :param int sample: The multi-sampled sample. Ignored if non-multisampled texture.