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Annotation of q_a/samples/streblt/readme.txt, revision 1.1.1.2

1.1       root        1:  Sample: StretchBlt Demonstration
                      2: 
                      3: Summary:
                      4: 
1.1.1.2 ! root        5: The STREBLT sample is an easy to use demonstration of the
1.1       root        6: StretchBlt API function. The program presents a dialog box
                      7: on the top of the window, and through this dialog box the
                      8: user can manipulate the parameters to StretchBlt. In the
                      9: main window, the source bitmap is displayed on the right
                     10: half of the window, and the destination bitmap is displayed
                     11: on the left half.
                     12: 
                     13: More Information:
                     14: 
                     15: The source and destination rectangles may be changed
                     16: directly in the dialog, or they may be changed by using the
                     17: direct manipulation objects in the two halves of the window.
                     18: Clicking and dragging the mouse in the upper-left corner
                     19: moves the rectangles; clicking and dragging the mouse in the
                     20: lower-right corner sizes the rectangles. The source direct
                     21: manipulation object is temporarily erased before calling
                     22: StretchBlt so that the top and left edges do not show in the
                     23: destination image.
                     24: 
                     25: The raster operation for the StretchBlt call may be changed
                     26: by altering the values in the right-most entry fields. The
                     27: contents are interpreted to be in hexadecimal. There is a
                     28: combo box directly beneath these entry fields that lists all
                     29: of the standard raster operations. If the user selects a
                     30: standard ROP from this combo box, its contents are copied
                     31: into the ROP entry fields and are then used in the
                     32: StretchBlt call.
                     33: 
                     34: Several of the raster operations make use of a pattern in
                     35: the destination HDC. For this reason, the program also
                     36: allows the user to select one of the standard pattern
                     37: brushes from a second combo box. This brush is selected into
                     38: the destination HDC just prior to making the StretchBlt
                     39: call.
                     40: 
                     41: The effect of the StretchBlt call is also affected by the
                     42: "StretchBlt mode" that has been set for the destination HDC.
                     43: A third combo box allows the user to select from any of the
                     44: standard modes. The difference is most easily observed when
                     45: stretching from a large source rectangle to a small
                     46: destination rectangle.
                     47: 
                     48: The "Draw" button may be chosen at any time to cause the
                     49: StretchBlt call to be made. This does not erase the
                     50: background, so that the effect of multiple ROPs on the HDC
                     51: can be observed. Manipulating the source rectangle also
                     52: causes a StretchBlt to occur without erasing the window.
                     53: However, manipulating the destination rectangle erases the
                     54: destination half of the window before the next StretchBlt is
                     55: called.

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