Method for rapid windowing of display information in computer graphics

Claim 1

A method for facilitating rapid windowing of image data in computer graphics wherein the picture data stored in refresh memory is organized in a hierarchical tree structure made up of connected nodes such that the entire picture is represented by the top node and parts of the picture are represented in descending nodes from said top node so that at the most bottom nodes (leaves) of the tree, a graphic primitive, representing a vector, string of text, or image raster data, make up the displayable picture, including the steps of: (a) dividing the displayable picture represented in a two-dimensional co-ordinate system into a number of boxes, (b) defining a master box greater than or equal to one of said boxes, (c) establishing a window of a preset number of said boxes less than or equal to the size of said master box such that said window represents the area of said picture which is to be displayed on the screen, (d) locating said window in relationship to said master box such that said window is contained in said master box, then (e) mapping bits of data called summaries into an NxN matrix, wherein NxN is equal to the number of boxes within the master box such that if a graphic primitive lies within a box within said master box then the summary has entered therein a one value and computing said summaries for branch nodes throughout said tree by ORing the summaries associated with the nodes of the tree and placing the result in an upper branch node and proceeding to OR the resulting summaries at the node branches of the tree in an ascending manner up the tree until the summary associated with the upper most node of the tree has been computed, (f) traversing said data tree from the summary for the top node of the tree through the summaries for said sub-nodes of the tree using the one value of the bits in said summaries to determine which of the branches of the tree contain graphic primitives at their nodes (g) identifying the location of the primitives within the grid of boxes, (h) clipping the graphic primitive to the size of said window box (i) displaying said clipped graphic primitives to render the image to the viewer.

Claim 2

A method for facilitating rapid windowing of image data in computer graphics wherein the picture data stored in refresh memory is organized in a hierarchical tree structure made up of connected nodes such that the entire picture is represented by the top node and parts of the picture are represented in descending nodes from said top node so that at the most bottom nodes (leaves) of the tree, a graphic primitive, representing a vector, string of text, or image raster data, make up the displayable picture, including the steps of: (a) dividing the displayable picture represented in a two-dimensional co-ordinate system into a number of boxes, (b) defining a master box greater than or equal to one of said boxes, (c) establishing a window of a preset number of said boxes less than or equal to the size of said master box such that said window represents the area of said picture which is to be displayed on the screen, (d) locating said window in relationship to said master box such that said window is contained in said master box, then (e) mapping bits of data called summaries into an NxN matrix, wherein NxN is equal to the number of boxes within the master box such that if a graphic primitive lies within a box within said master box then the summary has entered therein a one value and computing said summaries for branch nodes throughout said tree by ORing the summaries associated with the nodes of the tree and placing the result in an upper branch node and proceeding to OR the resulting summaries at the node branches of the tree in an ascending manner up the tree until the summary associated with the upper most node of the tree has been computed, (f) traversing said data tree from the summary for the top node of the tree through the summaries for said sub-nodes of the tree using the one value of the bits in said summaries to determine which of the branches of the tree contain graphic primitives at their nodes (g) identifying the location of the primitives within the grid of boxes, (h) clipping the graphic primitive to the size of said window box (i) displaying said clipped graphic primitives to render the image to the viewer.