st/mesa: fix SINT <-> UINT conversion during PBO upload / download

This fixes use cases like glReadPixels from an RGBA8I framebuffer into
a PBO with type GL_INT by clamping values appropriately when they fall
outside the range of the destination format.

Fixes parts of GL45-CTS.gtf32.GL3Tests.packed_pixels.packed_pixels_pbo.

Reviewed-by: Marek Olšák <[email protected]>
Reviewed-by: Edward O'Callaghan <[email protected]>

1 files changed, 6 insertions, 2 deletions

diff --git a/src/mesa/state_tracker/st_pbo.h b/src/mesa/state_tracker/st_pbo.h
index 6513093002d..54ae7768b4f 100644
--- a/src/mesa/state_tracker/st_pbo.h
+++ b/src/mesa/state_tracker/st_pbo.h
@@ -85,10 +85,14 @@ void *
 st_pbo_create_gs(struct st_context *st);
 
 void *
-st_pbo_get_upload_fs(struct st_context *st);
+st_pbo_get_upload_fs(struct st_context *st,
+                     enum pipe_format src_format,
+                     enum pipe_format dst_format);
 
 void *
-st_pbo_get_download_fs(struct st_context *st, enum pipe_texture_target target);
+st_pbo_get_download_fs(struct st_context *st, enum pipe_texture_target target,
+                       enum pipe_format src_format,
+                       enum pipe_format dst_format);
 
 extern void
 st_init_pbo_helpers(struct st_context *st);