meshcreate.java

在J2ME下面实现3D菜单,可以用于游戏开发(需要jsr184支持)

import javax.microedition.m3g.*;

public class MeshCreate {
    public static Mesh createItem(){

        
        short []POINTS = new short[] {
        		-4, -1, 1,      4, -1, 1,     4, 1, 1,      -4, 1, 1, //Front
                4, -1, -1,       -4, -1, -1,   -4, 1, -1,     4, 1, -1, //Back
                -4, -1, -1,      -4, -1, 1,   -4, 1, 1,      -4, 1, -1, //Left
                4, -1, 1,        4, -1, -1,     4, 1, -1,    4, 1, 1, //Right
                -4, 1, 1,        4, 1, 1,        4, 1, -1,    -4, 1, -1, // Top
                -4, -1, -1,      4, -1, -1,    4, -1, 1,     -4, -1, 1}; // Bottom
        
        short []TEXTCOORDINATES = new short[] {
        		0, 1,      1, 1,       1, 0,       0, 0,
                1, 0,      0, 0,       0, 1,       1, 1,
                0, 1,      1, 1,       1, 0,       0, 0,
                0, 1,      1, 1,       1, 0,       0, 0,
                0, 1,      1, 1,       1, 0,       0, 0,
                0, 1,      1, 1,       1, 0,       0, 0};

      int []FRONT_INDICES = new int[] {0, 1, 3, 2};
      int []BACK_INDICES = new int[] {4, 5, 7, 6};
      int []LEFT_INDICES = new int[] {8, 9, 11, 10};
      int []RIGHT_INDICES = new int[] {12, 13, 15, 14};
      int []TOP_INDICES = new int[] {16, 17, 19, 18};
      int []BOTTOM_INDICES = new int[] {20, 21, 23, 22};                                   
      int[] LENGTHS = new int[] {4}; 

        VertexArray POSITIONS_ARRAY, TEXTURE_ARRAY; 
        IndexBuffer []INDEX_BUFFER = new IndexBuffer[6];
        POSITIONS_ARRAY = new VertexArray(POINTS.length/3, 3, 2); 
        POSITIONS_ARRAY.set(0, POINTS.length/3, POINTS); 
        TEXTURE_ARRAY = new VertexArray(TEXTCOORDINATES.length/2, 2, 2);
        TEXTURE_ARRAY.set(0, TEXTCOORDINATES.length/2, TEXTCOORDINATES);
        
        INDEX_BUFFER[0] = new TriangleStripArray(FRONT_INDICES, LENGTHS);
        INDEX_BUFFER[1] = new TriangleStripArray(BACK_INDICES, LENGTHS);
        INDEX_BUFFER[2] = new TriangleStripArray(LEFT_INDICES, LENGTHS);
        INDEX_BUFFER[3] = new TriangleStripArray(RIGHT_INDICES, LENGTHS);
        INDEX_BUFFER[4] = new TriangleStripArray(TOP_INDICES, LENGTHS);
        INDEX_BUFFER[5] = new TriangleStripArray(BOTTOM_INDICES, LENGTHS);
        
        VertexBuffer vertexBuffer = new VertexBuffer(); 
        vertexBuffer.setPositions(POSITIONS_ARRAY, 1.0f, null); 
        vertexBuffer.setTexCoords(0, TEXTURE_ARRAY, 1.0f, null);
        vertexBuffer.setDefaultColor(0x80FFFFFF);
        Mesh mesh = new Mesh(vertexBuffer, INDEX_BUFFER, null); 

        Appearance []appearance = new Appearance[6];
        PolygonMode polygonMode = new PolygonMode();
        polygonMode.setPerspectiveCorrectionEnable(true);
        polygonMode.setCulling(PolygonMode.CULL_NONE);

        CompositingMode cm = new CompositingMode();
        cm.setBlending(CompositingMode.ALPHA);
        
        for(int i=0; i<appearance.length; i++){
            appearance[i] = new Appearance();
            appearance[i].setPolygonMode(polygonMode);
            mesh.setAppearance(i, appearance[i]);
        }

        return mesh;
    }
}