Minimum or maximum sample indexing in control surface

A non-transitory computer-readable storage medium having stored thereon data representing sequences of instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• writing a new color sample or depth sample value for a pixel in a resource of a memory, the resource containing a plurality of sample values;
• reading a control surface for the resource;
• obtaining indexing including a minimum sample index and a maximum sample index from the control surface;
• comparing the new sample value to one or more of a current minimum sample value indicated by the minimum sample index or a current maximum sample value indicated by the maximum sample index;
• and
• updating the minimum sample index or the maximum sample index in the control surface if required based on the comparing of the new sample value with one or more of the current minimum sample value or the current maximum sample value.

A processing system comprising:

• a central processing unit (CPU);
• a memory for storage of data including pixel sample values;
• and
• a graphics processor including:
• a sampler to sample a value,
• one or more of a color unit or a depth unit, the color unit or depth unit including a backend subunit, and
• at least one minimum or maximum sample (min/max) setter subunit for the color unit or depth unit, the min/max setter subunit to receive a new sample value from the backend subunit of the color unit or depth unit, store the sample value in a resource of the memory containing a plurality of sample values, and update indexing in a control surface including index values for one or more of a minimum sample value and a maximum sample value in the plurality of sample values of the resource.