CN1112634C - A hierarchical comparison device for polygonal images - Google Patents

Abstract

The polygon portrait level comparing device is composed of plural level processing units, which includes: a depth register for storing depth data representing the polygon image; a color code register for storing color code data representing the polygon image; a level controller as a control device for outputting color code data, wherein when the image is to be displayed, the level controller receives the depth data of the depth register and compares the depth data with the depth data output by the next level processing unit, and when the depth data with the lightest level is found, the level controller of the next level processing unit outputs a control signal to enable the color code register to output the color code data; and a tri-state buffer.

Description

A hierarchical comparison device for polygonal images

The present invention relates to a layer comparison device for polygonal images, in particular to a layer comparison device composed of complex layer processing units.

Usually, when dealing with multi-level or multi-depth polygonal images, most of the well-known devices used are field depth registers (Z-Frame Buffer), which store various polygonal images through field registers, and then compare their depths one by one. In order to obtain the image with the shallowest level, and the above-mentioned process will cause the processing speed to be too slow, and the required storage capacity is also very large.

In view of this, the object of the present invention is to provide a kind of level comparison device of polygonal image in order to solve the above-mentioned problem, in order to save memory and find out the image with the shallowest level in a short time, wherein, this device is made up of multiple levels It consists of a hierarchical processing unit, and the hierarchical processing unit further includes:

A depth register for storing depth data representing a polygon image;

a color code register, used to store color code data representing the polygon image;

A layer controller (Layer Controller) is used as a color code data output control device. When the layer controllers of each level compare the depth data contained in the layer processing unit of a certain level as the shallowest level, the output color code data; and

A three-state buffer is driven by the control signal output by the layer controller, and can provide the function of multiplexer for the output of color code data.

In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and understandable, a preferred embodiment is specifically cited, and in conjunction with the accompanying drawings, it is described in detail as follows:

Brief description of the drawings

Fig. 1 is a block diagram for showing the hierarchical comparison device of the present invention;

FIG. 2 is a circuit diagram showing a layer controller.

Referring now to Fig. 1, the level comparison device of the polygonal portrait of the present invention is made up of the level processing units of complex arrays, wherein, taking the working relationship between the level processing unit 20 and the series as an example, it is described as follows:

(1) A first-level processing unit 20, including:

A depth register Z2, which is used to store the depth data d2 representing the polygon image;

A color code register C2, which is used to store the color code data representing the polygon image;

A level controller L2 has an input enable line EN2. When the image is to be displayed, a circuit (not shown in the figure) that controls the shape of the polygonal image outputs an enable signal EN2 to the level controller L2. At this time, The level controller L2 will receive the depth data d2 from the depth register Z2 of the level through Zb2, and receive the shallower depth data Zo3 from the next level through Zi2, and compare the two depth data d2 with Zo3 to find out which one is the best The level of depth data is relatively shallow, and it is sent to the upper level through the depth data output terminal Zo2 to continue the comparison. At this time, in the above comparison process, the level controller L2 will receive the control signal go1 from the upper level through gi2 In order to know the comparison result between the depth data output by this level Zo2 and the depth data d1 of the previous level, and finally determine the output value out2 of the level controller L2 according to the result, and send a control signal go2 to the next level Controller L3;

A tri-state buffer b2 is used to receive the color code data of the color code register C2, has the function of a multiplexer, and its action is controlled by the output value out2 of the layer controller L2.

(2) Working relationship between series:

Assuming that the level comparison device of the polygonal image is composed of three levels of level processing units 10, 20, 30, then

(a) The layer processing unit 30 transmits the layer depth data d3 from Zo3 to the layer processing unit 20 .

(b) The level processing unit 20 receives the depth data d3 of the next level level processing unit 30 through Zi2, and receives the depth data d2 of this level through Zb2. The signal go2 suppresses the color code output of the next level processing unit 30, and sends the depth data d2 to the upper level processing unit 10 for further comparison.

(c) The level processing unit 10 receives the depth data d2 of the next level level processing unit 20 from Zi1, and receives the depth data d1 of this level through Zb1. After comparing the two, it is found that the level of the depth data d2 is still relatively shallow, so it is sent out The control signal go1 is used to drive the color code output of the next level processing unit 20, and because the level processing unit 10 is at the top level, the control signal go1 suppresses the color code output of this level.

(d) To sum up, the depth data d2 of the layer processing unit 20 has the shallowest layer, so after receiving the control signal go1, the output value out2 of the layer controller L2 drives the tri-state buffer b2 of this stage, so that the color code can Output to the color palette (RAM DAC). In addition, because the depth data d1 and d3 of the layer processing units 10 and 30 are not the shallowest, after receiving the control signals go1 and go2, the layer controllers L1 and L3 output the values out1 and out3 To suppress the tri-state buffer b1, b3, so that the color code cannot be output.

Therefore, the layer comparison device for polygonal images of the present invention does not need a large amount of memory, and can capture the depth data with the shallowest layer at a very fast processing speed.

Referring now to Fig. 2, there is a circuit device about the layer controller L2, including:

A comparator P2, whose input terminal A receives the depth data d2 from the depth register Z2, and the input terminal B receives the depth data Zo3 from the lower layer, which is relatively shallow, and is compared by the comparator P2. If the depth data d2 is relatively shallow , the comparator P2 outputs a signal O2 of logic 1, if the level of the depth data Zo3 is relatively shallow, the comparator P2 outputs a signal O2 of logic 0;

An AND gate U1, connected to the enable line EN2 and a signal O2 from the comparator P2, and the two output a comparison signal g2 through the AND gate U1;

A multiplexer M2, its enabling terminal S is connected to the comparison signal g2, its input terminal 1 receives the depth data d2 of this level, and its input terminal 0 receives the shallower depth data Zo3 from the next level, when the comparison signal g2 When it is logic 1, the multiplexer M2 transmits the depth data d2 of this level to the upper level processing unit 10 through the output terminal Zo2, and when the comparison signal g2 is logic 0, the multiplexer M2 transmits the data from the next level through the output terminal Zo2 Depth data Zo3 to the upper level processing unit 10;

An OR gate U2, which is connected to a comparison signal g2 of this level and a control signal go1 of the upper level processing unit 10 received by gi2, and the two output a control signal go2 to the next level through the OR gate U2;

An AND gate U3, which is connected to a comparison signal g2 of the stage and an inversion control signal go1 from the upper stage to generate the output value out2;

When the comparator P2 compares the depth data Zo3 from the next stage with the depth data d2 of this stage and finds that the depth data d2 is shallower, it sends a logic 1 signal 02, and sends a logic 1 signal through the AND gate U1 The comparison signal g2, the multiplexer M2 is opened by the comparison signal g2 so that the depth data d2 can be transmitted to the upper level to continue the comparison;

And when the depth data d2 obtained by the comparison of the upper-level layer processing unit 10 is still relatively shallow, a control signal go1 of logic 0 is sent to the layer processing unit 20, and the control signal go1 becomes logic 0 through the inverting input terminal. The go1 of 1, and the comparison signal g2 of logic 1 makes the output value out2 become logic 1 through the AND gate U3, so that the tri-state buffer b2 can be driven to output the color code, and the second is the comparison signal g2 of the logic 1 through the OR gate U2 outputs a logic 1 control signal go2 to suppress the tri-state buffers of the processing units at all levels below, so that the color code cannot be output.

To sum up, the layer comparison device for polygonal portraits of the present invention includes multiple layers of layer processing units, which use layer controllers at all levels to compare various depth data, and continue to send shallower layer depth data to the upper level for comparison. At the same time, a control signal is sent back to turn off the layer processing unit that does not have the shallowest depth data stored, until finally, only the layer processing unit that stores the shallowest depth data can send the color code data to the palette.

Although the present invention is disclosed above with a preferred embodiment, it is not intended to limit the present invention. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims (2)

1. A layer comparison device for polygonal images, which is composed of multiple levels of layer processing units, which are used to determine the image with the shallowest layer, and each level of layer processing units includes: A depth register for storing depth data representing a polygon image; a color code register, used to store color code data representing the polygon image; A layer controller is used as a control device for outputting color code data. When the image is to be displayed, the layer controller receives the depth data of the aforementioned depth register and compares it with the depth data output by the next layer processing unit, and at the same time , transmit the shallower depth data of the two to the upper level processing unit to continue the comparison until it is confirmed that the depth data stored in a certain level processing unit has the shallowest level, that is, send back a control signal to the level controller To make the color code register of this level output the color code data; and A three-state buffer is driven by the control signal output by the layer controller, and can provide the function of multiplexer for the output of color code data. 2. The apparatus of claim 1, wherein the hierarchical controller further comprises: A comparator, the input end of which is used to receive the depth data of the level and from the lower level controller, compare the hierarchical relationship between the two through the comparator, and then obtain a comparison result and output a comparison signal, and the comparison signal can pass through the gate The circuit transmits the control signal to the three-state buffer and the lower-level controller to control the output status of the color code data at each level; A multiplexer, the input end of which is used to receive the depth data of the level and from the lower layer controller, and the enable end receives the comparison signal output by the comparator, that is, the comparison signal of the comparator enables the multiplexer, The multiplexer selects the shallower depth data from the two to be sent to the upper level controller for further comparison.