Android OpenGL:图形四基色褪色问题
我正在用OpenGL ES在Android上画一个白色的四边形,颜色正在褪色 见图: 我用Android OpenGL:图形四基色褪色问题,android,opengl-es,geometry,fading,Android,Opengl Es,Geometry,Fading,我正在用OpenGL ES在Android上画一个白色的四边形,颜色正在褪色 见图: 我用intnumvertices=4尝试过它也是,但我得到的不是红色而是黑色。怎么回事 int numVertices = 6; private FloatBuffer vertexBuffer, colorBuffer; private ShortBuffer indexBuffer; private short[] indices = { 0, 1, 2,
intnumvertices=4尝试过它代码>也是,但我得到的不是红色而是黑色。怎么回事
int numVertices = 6;
private FloatBuffer vertexBuffer, colorBuffer;
private ShortBuffer indexBuffer;
private short[] indices = { 0, 1, 2,
2, 3, 0 };
public Floor (float coords[][]) {
float vertices[] = new float[numVertices*3];
float colors[] = new float[numVertices*4];
//Set colors
for(int i=0; i < numVertices; i++){
colors[i] = 1.0f; //red
colors[i+1] = 1.0f; //grn
colors[i+2] = 1.0f; //blu
colors[i+3] = 1.0f; //alpha
}
vertices[0] = coords[0][0];
vertices[1] = coords[0][1];
vertices[2] = coords[0][2];
vertices[3] = coords[1][0];
vertices[4] = coords[1][1];
vertices[5] = coords[1][2];
vertices[6] = coords[2][0];
vertices[7] = coords[2][1];
vertices[8] = coords[2][2];
vertices[9] = coords[3][0];
vertices[10] = coords[3][1];
vertices[11] = coords[3][2];
ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4);
vbb.order(ByteOrder.nativeOrder());
vertexBuffer = vbb.asFloatBuffer();
vertexBuffer.put(vertices);
vertexBuffer.position(0);
ByteBuffer cbb = ByteBuffer.allocateDirect(colors.length * 4);
cbb.order(ByteOrder.nativeOrder());
colorBuffer = cbb.asFloatBuffer();
colorBuffer.put(colors);
colorBuffer.position(0);
ByteBuffer ibb = ByteBuffer.allocateDirect(indices.length * 2);
ibb.order(ByteOrder.nativeOrder());
indexBuffer = ibb.asShortBuffer();
indexBuffer.put(indices);
indexBuffer.position(0);
}
/**
* This function draws our square on screen.
* @param gl
*/
public void draw(GL10 gl) {
gl.glDisable(GL10.GL_COLOR_MATERIAL);
gl.glDisable(GL10.GL_BLEND);
gl.glDisable(GL10.GL_LIGHTING);
gl.glEnableClientState(GL10.GL_COLOR_ARRAY);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
gl.glColorPointer(4, GL10.GL_FLOAT, 0, colorBuffer);
gl.glPointSize(2.0f);
gl.glDrawElements(GL10.GL_TRIANGLES, indices.length, GL10.GL_UNSIGNED_SHORT, indexBuffer);
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_COLOR_ARRAY);
}
int数值=6;
私有浮动缓冲区vertexBuffer、colorBuffer;
私人短缓冲区索引缓冲区;
私有短[]索引={0,1,2,
2, 3, 0 };
公共楼层(浮动坐标[]){
浮动顶点[]=新浮动[numvitices*3];
浮动颜色[]=新浮动[数值*4];
//定色
对于(int i=0;i
}
谢谢你的帮助
找到了答案。对于其他遇到此问题的人,需要进行修复:
int numVertices = 4;
//Set colors
for(int i=0; i < numVertices; i++){
colors[i*4] = 1.0f; //red
colors[i*4+1] = 1.0f; //grn
colors[i*4+2] = 1.0f; //blu
colors[i*4+3] = 1.0f; //alpha
}
int数值=4;
//定色
对于(int i=0;i
用于(int i=0;i
这和你想象的不一样。您需要编写i+=4
否则,您将初始化numVertices/4+4组件,而不是按预期初始化numVertices*4
for(int i=0; i < numVertices; i++){
colors[i] = 1.0f; //red
colors[i+1] = 1.0f; //grn
colors[i+2] = 1.0f; //blu
colors[i+3] = 1.0f; //alpha
}