Abstract: A graphics processing system is configured to render primitives using a rendering space that is sub-divided into sections, wherein the graphics processing system includes assessment logic configured to make an assessment regarding the presence of primitive edges in a section, and determination logic configured to determine an anti-aliasing setting for the section based on the assessment.

Abstract: Methods and tiling engines for storing tiling primitives in a graphics processing system.

Abstract: A lossy method of compressing data, such as image data, which uses wrap-around wavelet compression is described. Each data value is divided into two parts and the first parts, which comprise the most significant bits from the data values, are compressed using wrap-around wavelet compression. Depending upon the target compression ratio and the compression ratio achieved by compressing just the first parts, none, one or more bits from the second parts, or from a data value derived from the second parts, may be appended to the compressed first parts. The method described may be lossy or may be lossless. A corresponding decompression method is also described.

Abstract: A system and method for performing intersection testing of rays in a ray tracing system. The ray tracing system uses a hierarchical acceleration structure comprising a plurality of nodes, each identifying one or more elements able to be intersected by a ray. The system makes use of a serial-mode ray intersection process, in which, when a ray intersects a bounding volume, a limited number of new ray requests are generated.

Abstract: A decoder is configured to decode a plurality of texels from a received block of texture data encoded according to the Adaptive Scalable Texture Compression (ASTC) format, and includes a parameter decode unit configured to decode configuration data for the received block of texture data, a colour decode unit configured to decode colour endpoint data for the plurality of texels of the received block in dependence on the configuration data, a weight decode unit configured to decode interpolation weight data for each of the plurality of texels of the received block in dependence on the configuration data, and at least one interpolator unit configured to calculate a colour value for each of the plurality of texels of the received block using the interpolation weight data for that texel and a pair of colour endpoints from the colour endpoint data.

Abstract: Methods and primitive block generators for generating primitive blocks in a graphics processing system. The methods comprise: receiving transformed position data for a current primitive, the transformed position data indicating a position of the current primitive in rendering space; determining a distance between the position of the current primitive and a position of a current primitive block based on the transformed position data for the current primitive; determining whether to add the current primitive to the current primitive block based on the distance and a fullness of the current primitive block; in response to determining that the current primitive is to be added to the current primitive block, adding the current primitive to the current primitive block; and in response to determining that the current primitive is not to be added to the current primitive block, flushing the current primitive block and adding the current primitive to a new current primitive block.

Abstract: A hardware logic representation of a circuit to implement an operation to perform multiplication by an invariant rational is generated by truncating an infinite single summation array (which is represented in a finite way). The truncation is performed by identifying a repeating section and then discarding all but a finite number of the repeating sections whilst still satisfying a defined error bound. To further reduce the size of the summation array, the binary representation of the invariant rational is converted into canonical signed digit notation prior to creating the finite representation of the infinite array.

Abstract: A texture filtering unit includes a datapath block and a control block. The datapath block includes one or more parallel computation pipelines, each containing at least one hardware logic component configured to receive a plurality of inputs and generate an output value as part of a texture filtering operation. The control block includes a plurality of sequencers and an arbiter. Each sequencer executes a micro-program that defines a sequence of operations to be performed by the one or more pipelines in the datapath block as part of a texture filtering operation and the arbiter controls access, by the sequencers, to the one or more pipelines in the datapath based on predefined prioritization rules.

Abstract: Time stamp replication within wireless networks is described. In an embodiment, a wireless station receives an input time stamp and uses this input time stamp to generate an output time stamp. The wireless station transmits the output time stamp to wireless stations in one of a number of groups which make up the wireless network. The output time stamp is generated to compensate for delays between receiving the input time stamp and transmitting the output time stamp such that output time stamp which is transmitted at a time T corresponds to the value that the input time stamp would have had if it had been received at time T (and not at a time earlier than T). This may, therefore, reduce or eliminate independent time stamp errors and jitter caused by multiple disparate systems and processes.

Abstract: An adder and a method for calculating 2n+x are provided, where x is a variable input expressed in a floating point format and n is an integer. The adder comprises: a first path configured to calculate 2n+x for x<0 and 2n?1?|x|<2n+1; a second path configured to calculate 2n+x for |x|<2n; a third path configured to calculate 2n+x for |x|?2n; and selection logic configured to cause the adder to output a result from one of the first, second, and third paths in dependence on the values of x and n.

Abstract: Methods of arbitrating between requestors and a shared resource wherein for each processing cycle a plurality of select signals are generated and then used by decision nodes in a binary decision tree to select a requestor. The select signals are generated using valid bits and priority bits. Each valid bit corresponds to one of the requestors and indicates whether, in the processing cycle, the requestor is requesting access to the shared resource. Each priority bit corresponds one of the requestors and indicates whether, in the processing cycle, the requestor has priority. Corresponding valid bit and priority bits are combined in an AND logic element to generate a valid_and_priority bit for each requestor. Pair-wise OR-reduction is then performed on both the valid bits and the valid_and_priority bits to generate additional valid bits and valid_and_priority bits for sets of requestors and these are then used to generate the select signal.

Abstract: A method for generating an augmented reality image from first and second images, wherein at least a portion of at least one of the first and the second image is captured from a real scene, identifies a confidence region in which a confident determination as to which of the first and second image to render in that region of the augmented reality image can be made, and identifies an uncertainty region in which it is uncertain as to which of the first and second image to render in that region of the augmented reality image. At least one blending factor value in the uncertainty region is determined based upon a similarity between a first colour value in the uncertainty region and a second colour value in the confidence region, and an augmented reality image is generated by combining, in the uncertainty region, the first and second images using the at least one blending factor value.

Abstract: A method of converting 10-bit pixel data (e.g. 10:10:10:2 data) into 8-bit pixel data involves converting the 10-bit values to 8-bits using a technique that is selected dependent upon the values of the MSBs of the 10-bit values and setting the value of an HDR flag dependent upon the values of the MSBs. The HDR flag is appended to the 3-bit channel.

Abstract: A graphics processing system includes a tiling unit configured to tile a first view of a scene into a plurality of tiles, a processing unit configured to identify a first subset of the tiles that are associated with regions of the scene that are viewable in a second view, and a rendering unit configured to render to a render target each of the identified tiles.

Abstract: A tessellation method uses tessellation factors defined for each vertex of a patch which may be a quad, a triangle or an isoline. The method is implemented in a computer graphics system and involves comparing the vertex tessellation factors to a threshold. If the vertex tessellation factors for either a left vertex or a right vertex, which define an edge of an initial patch, exceed the threshold, the edge is sub-divided by the addition of a new vertex which divides the edge into two parts and two new patches are formed. New vertex tessellation factors are calculated for each vertex in each of the newly formed patches, both of which include the newly added vertex. The method is then repeated for each of the newly formed patches until none of the vertex tessellation factors exceed the threshold.

Abstract: A hardware design for a component that evaluates a main algebraic expression comprising at least two variables is verified, the main algebraic expression being representable as a lossless combination of a plurality of sub-algebraic expressions, and one or more of the at least two variables can be constrained to cause an instantiation of the hardware design to evaluate each of the sub-algebraic expressions. An instantiation of the hardware design is verified as correctly evaluating each of the plurality of sub-algebraic expressions, and the instantiation of the hardware design is formally evaluated as correctly evaluating one or more combinations of sub-algebraic expressions, wherein the one or more combinations comprises a combination that is equivalent to the main algebraic expression.

Abstract: A method and an apparatus for clocking data processing modules, with different average clock frequencies and for transferring data between the modules are provided. The apparatus includes a device for providing a common clock signal to the modules. Clock pulses are deleted from the common clock signal to individual modules in dependence on the clocking frequency required by each module. The clock pulses are applied to the modules between which the data is to be transferred at times consistent with the data transfer.

Abstract: A method and compression unit for compressing a block of image data to satisfy a target level of compression, wherein the block of image data comprises a plurality of image element values, each image element value comprising one or more data values relating to a respective channel. For each of the channels: (i) an origin value for the channel for the block is determined, (ii) difference values are determined representing differences between the data values and the determined origin value for the channel for the block, and (iii) a first number of bits for losslessly representing a maximum difference value of the difference values for the channel for the block is determined.

Abstract: A decompression method determines image element values from compressed data representing a block of image element values relating to a respective one or more channels. For each of the channels, an indication of a first number of bits representing difference values between the data values and an origin value for the channel is read from the compressed data. For each of the channels, a second number of bits is obtained, wherein representations of the difference values for each of the channels are included in the compressed data using the second number of bits for that channel. The obtained second numbers of bits for the respective channels are used to read the representations of the difference values for the image element values being decompressed. Based on the representations of the difference values, a difference value is determined in accordance with the first number of bits for the channel.

Abstract: A graphics processing system configured to use a rendering space which is subdivided into a plurality of tiles, includes geometry processing logic having geometry transform and sub-primitive logic configured to receive graphics data of input graphics data items, and to determine transformed positions within the rendering space of one or more sub-primitives derived from the input graphics data items using a plurality of shader stages; and a tiling unit configured to generate control stream data including sub-primitive indications to indicate which of the sub-primitives are to be used for rendering each tile. The geometry processing logic is configured to write to a memory, for each instance of a pre-determined shader stage, shader stage output data comprising data output from each instance of the pre-determined shader stage used to process the received graphics data.