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The array of surface elevation data is populated by the code in Listing 2 .
| Listing 2. A 3D parabolic surface, |
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for(int row = 0;row<numberRows;row++){
for(int col = 0;col<numberCols;col++){
int xSquare = col * col;int ySquare = row * row;
data[row][col] = xSquare + ySquare;}//end col loop
}//end row loop |
I will allow you to evaluate this code on your own. It creates a 3D surface with the lowest elevation at the upper left corner and the highest elevation atthe lower right corner. The surface is a one-quarter section of a 3D parabola, as shown in Figure 3 .
Listing 3 shows the code that causes the 3D surface elevation data to be displayed as six independent images (each statement in Listing 3 produces one output image) .
IMPORTANT: this is the same code that would be used by other programs to incorporate this 3D surface plottingcapability into those programs.
| Listing 3. Display six surface images. |
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new ImgMod29(data,blockSize,true,0);
new ImgMod29(data,blockSize,false,1);new ImgMod29(data,blockSize,true,2);
new ImgMod29(data,blockSize,true,3);new ImgMod29(data,blockSize,false,4);
new ImgMod29(data,blockSize,true,5); |
All that is necessary for another program to incorporate this class to display a 3D surface is to instantiate an object of the class named ImgMod29 passing four parameters to the constructor.
The first parameter is a reference to the 2D array of type double containing the surface elevation values.
The second parameter is the blockSize . This int value specifies the size of one side of a square of pixels, (all of the same color) that will be used to represent each surface elevation value in the final display. As mentioned earlier, this value was set to 2 in the sampledisplays produced by the main method. However, it could have been any reasonable value such as 5, 10, or 15 for example.
The third parameter is true if you want the red axes to be drawn and is false otherwise (as shown in Figure 3 ) .
The fourth parameter is an integer value between 0 and 5 inclusive, which specifies the plotting format as follows:
Listing 3 instantiates six such objects to display the same 3D surface, one for each plotting format as shown in Figure 3 . Some of the objects display the axes and others do not. All use a blockSize value of 2.
Each display object appears in the upper-left corner of the screen. Thus, when two or more such objects are instantiated, they appear as a stack. It isnecessary to physically move those on top of the stack to see those further down.
Listing 3 signals the end of the main method.
Listing 4 shows the beginning of the class named ImgMod29 and the beginning of the constructor for the class.
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