Microsoft Technology Licensing, LLC

Amit Chatterjee

Stuart Raymond Patrick

Stuart T Laney

Ralph A Lipe

Raymond Edward Endres

David Neal Weise

Richard Allen Pletcher

Michael Scott Gibson

Displaying images having pixels thereof that are meant to be transparent is disclosed. In one embodiment, a method includes a first stage and a second stage. The first stage is performed once, to transform the image and generate a mask thereof. The second stage is performed each time the image is to be displayed, to copy the transformed image and the mask onto the display. In one embodiment, the transparent image is shrunk and/or stretched when displayed. The cases of animated images and dithering for alpha blending are also disclosed and covered by the invention.

Display of images with transparent pixels

Operating system enhancements that enable an application program to create and perform graphics operations on device-independent bitmaps (DIBs) efficiently. The enhancements are in the form of functions that return to the application program a handle to the DIB and a pointer to the location of the DIB in memory. With the handle, the application program can use the capabilities of the operating system to perform graphics operations on the DIB. With the pointer, the application program can use its own drawing capabilities and address the DIB directly. The operating system enhancements also streamline the design and content of graphics drivers such as display drivers by placing basic graphics functions in a graphics engine that communicates with the graphics driver. Simple graphics operations are passed from the graphics driver to the graphics engine, allowing the driver to be limited to more complex operations that utilize special characteristics of graphics hardware associated with the driver.

Method and apparatus for creating and performing graphics operations on device-independent bitmaps

Operating system enhancements that enable an application program to create and perform graphics operations on device-independent bitmaps (DIBs) efficiently. The enhancements are in the form of functions that return to the application program a handle to the DIB and a pointer to the location of the DIB in memory. With the handle, the application program can use the capabilities of the operating system to perform graphics operations on the DIB. With the pointer, the application program can use its own drawing capabilities and address the DIB directly. The operating system enhancements also streamline the design and content of graphics drivers such as display drivers by placing basic graphics functions in a graphics engine that communicates with the a graphics driver. Simple graphics operations are passed from the graphics driver to the graphics engine, allowing the driver to be limited to more complex operations that utilize special characteristics of graphics hardware associated with the driver.

Method and apparatus for creating and performing graphics operation on device-independent bitmaps

In response to a change in the color depth of a computer system's display device, the invention dynamically changes the color depth of existing objects in system memory to match the changed color depth of the device. As a result open applications need not be shut down and then reopened to change the color depth of objects already in system memory. The dynamic changing is accomplished through a number of functions calls between an application, the operating system and a display driver. In one embodiment of the invention, copies with the changed color depth are made at one time of all objects in system memory and the original objects discarded. The copies are then transferred to screen memory (if the display device is a video display terminal) for display as they are requested. In another embodiment of the invention, copies with the changed color depth are made selectively as the objects are transferred to the screen memory. The copies are then discarded from system memory after transfer and the original objects retained.

Method and apparatus for dynamically changing the color depth of objects displayed in a computer system

A method and apparatus for efficiently transferring a data block of bytes from a source to a destination in memory of a computer system. The method transfers bytes in multiple-byte words on word-aligned boundaries of memory as much as possible to reduce the number of fetches and writes and the number of memory cycles required to execute the transfer. For handling data block transfers of various sizes and locations, the method is implemented in a compiler that compiles different portions of code at run time into a block of code that is then immediately executed. The compiler employs a state machine stored in memory and having a plurality of states. Each state is associated with a portion of code for aligning a destination address or for transferring bytes in multiple-byte words on word-aligned boundaries. The states correspond to different starting source and destination addresses. A number of state machines are provided corresponding to the different color formats (bits per pixel) that may exists in the source and destination.

Run-time code compiler for data block transfer

Method and apparatus for dynamically changing the color depth of objects

Method and apparatus for creating and performing graphics operations on

A method and apparatus for providing access to a banked peripheral memory via a contiguous linear address space. The present invention provides a linear address space having a present region that is mapped to a host memory region of a computer system. The present invention further provides a relocatable selector that provides access to a portion of the linear address space. Accessing programs exchange data with the banked peripheral memory via the relocatable linear address space. When an accessing program references an address of the relocatable address base that is not mapped to the present region, the relocatable linear address space is positioned so that the referenced address maps to the present region. Additionally, a bank of the peripheral memory that corresponds to the referenced address is also mapped into the host memory region so as to enable the accessing program to exchange data with the banked peripheral memory via the relocatable linear address space.

Method and apparatus for simulating banked memory as a linear address

Method and apparatus for transferring a brush pattern of pixels stored in memory to a destination bitmap in memory. The method transfers an entire row of the brush pattern to the scan line of a destination bitmap without checking each byte for the end of the row. Data bytes are fetched from the pixel row a predetermined number of times to transfer the pixel row in one pass. The transfer method preferably uses multiple-byte words on word-aligned boundaries of memory to reduce the number of fetches and writes and the number of memory cycles to execute the transfer. The transfer may include combining the pattern with a bitmap such as a source bitmap or the destination bitmap and transferring the combination to the destination bitmap. To accelerate the transfer process, a compiler is provided to compile, in response to an appropriate function call, run time code that is then immediately executed to transfer the pattern to the destination bitmap.

Method and apparatus for transferring a brush pattern to a destination

A method for storing a sequence consisting of a repeated data pattern of three bytes to a memory in double word increments aligned with double word boundaries. A register is loaded with the first four bytes of the sequence. The contents of the register are then repeatedly stored to consecutive locations of the memory. Between each storing of the register's contents, the contents are updated to the next four bytes of the sequence by shifting the second through fourth bytes to the first through third bytes and also moving the second byte to the fourth byte. When the beginning address where the sequence is to be stored in memory is not aligned with a double word boundary, the initial bytes of the sequence up to the double word boundary are stored and the contents of the register updated to the next four bytes of the sequence.

Method and apparatus for efficient transfer of data to memory

In response to a command to draw text on a screen, a computer's operating system creates a superglyph bitmap that combines text and a background color into a single bitmap. The bitmap is then transferred to screen memory by either a graphics driver or the operating system itself, depending upon whether the graphics driver has special characteristics for displaying the bitmap such as monochrome-to-color conversion. With this division of tasks, graphics drivers may be simplified to handle tasks for which they are uniquely qualified and the operating system handles more general tasks such a creating the bitmap. The concept may also be applied to other types of bitmaps, wherever it is advantageous to create bitmaps with the operating system and transfer bitmaps with either a graphics driver or the operating system.

Method and apparatus for creating and transferring a bitmap

The speed of bitmap block transfers involving image transformations between source and destination bitmaps is increased by forming a mapping array with entries corresponding one-to-one to elements of destination bitmap scan lines. A preprocessor fills the entries of the mapping array with indices of elements in a source scan line that map according to the image transformation to the elements of a destination scan line that correspond with the array entries. A block transfer compiler can then generate code to perform the transfer which uses the mapping array in an indexed look-up operation to determine the source element to transfer to each element of each scan line of the destination bitmap.

Bitmap block transfer image conversion

The stack pointer register in a computer is made available for general purpose use by programs executing at lower privilege levels than interrupt handlers. A set of instructions in such programs, excluding stack operations, stores data other than the stack pointer, such as operands, and the like, in the stack pointer register. When switching execution to an interrupt handler on an interrupt, return address data for the currently executing program is pushed onto a stack at the interrupt handler's privilege level. Thus, storing other data in the stack pointer register does not result in stack corruption. Also, these instructions can store data in a scratch portion of a stack segment beyond the current stack pointer.

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Redmond, WA, United States of America

Amit Chatterjee