Method and means for texture display in raster scanned color graphic

A raster scanned color graphics system comprising:

• an raster scanned display means (27);
• first addressible memory means (10) for storing a display image pel array of color numbers in memory locations corresponding to pel array positions;
• means (105, 101, 103, 5) for accessing the first memory for fetching color numbers from consecutive locations in raster scan order;
• means for deriving a color value v as a joint function of the color number k stored in any given location and the value of any subset of addressing bits from the accessing means defining the pel position;
• and
• means (23, 25) for applying the color value to the display means.

A raster scanned color graphics system including an raster scanned display means (27);

• a refresh buffer memory means (10) for storing a display image pel array of color numbers k at counterpart addressible locations;
• and means (101, 103, 105) for accessing the color numbers from the refresh memory in raster scan order;
• wherein the improvement comprises:
• first means (201) for deriving a selection signal (k.sub.2) indicative of a superpattern as a joint function of the color number k accessed from the refresh buffer and a first predetermined subset of address bits (x.sub.n-2, x.sub.n-3, y.sub.n-2, y.sub.n-3) from the accessing means defining the pel array position of k;
• second means (203) for deriving a color value v indicative of a selected subpattern as a joint function of the color number k from the first means, a second predetermined subset of address bits (x.sub.n-1, y.sub.n-1) from the accessing means defining the pel array position of k, and the selection signal (k.sub.2);
• and
• means for applying the color value to the display means.

A raster scanned color graphics system including an raster scanned display means (27);

• a refresh buffer memory means (10) for storing a display image pel array of color numbers k at counterpart addressible locations;
• means (1,3,5) for accessing the color numbers k from the refresh memory in raster scanned order at an array address defined by the contents of a first register means (101,103);
• and means (20, 25) for deriving a color value v from a corresponding color number k accessed from the refresh buffer and applying said color value v to the display means;
• wherein the improvement comprises:
• a second register means (107) for storing texture information;
• the accessing means includes means (35) for deriving a color number k as a joint function of the first register contents and a predetermined subset of address bits and for inserting said derived color number at a refresh buffer memory location defined by the first register means contents.