Pica/CommandProcessor: Implement parameter masking.

1 files changed, 12 insertions, 1 deletions

diff --git a/src/video_core/command_processor.h b/src/video_core/command_processor.h
index 6b6241a2..955f9dae 100644
--- a/src/video_core/command_processor.h
+++ b/src/video_core/command_processor.h
@@ -17,11 +17,22 @@ union CommandHeader {
     u32 hex;
 
     BitField< 0, 16, u32> cmd_id;
+
+    // parameter_mask:
+    // Mask applied to the input value to make it possible to update
+    // parts of a register without overwriting its other fields.
+    // first bit:  0x000000FF
+    // second bit: 0x0000FF00
+    // third bit:  0x00FF0000
+    // fourth bit: 0xFF000000
     BitField<16,  4, u32> parameter_mask;
+
     BitField<20, 11, u32> extra_data_length;
+
     BitField<31,  1, u32> group_commands;
 };
-static_assert(std::is_standard_layout<CommandHeader>::value == true, "CommandHeader does not use standard layout");
+static_assert(std::is_standard_layout<CommandHeader>::value == true,
+              "CommandHeader does not use standard layout");
 static_assert(sizeof(CommandHeader) == sizeof(u32), "CommandHeader has incorrect size!");
 
 void ProcessCommandList(const u32* list, u32 size);