这可能与我的转变有关，但是现在我无法弄清楚这一点，这让我心急如焚。我已经包装了绘制代码，以便我可以轻松定义新的三角形。但是，当我把它放入一个函数时，它只显示一个灰色的屏幕。功能代码如下：
public void Draw(float[] mViewMatrix, float[] mModelMatrix, float[] mProjectionMatrix, int mPositionHandle, int mColorHandle, int mMVPMatrixHandle)
{
long time = SystemClock.uptimeMillis() % 10000L;
float angleInDegrees = (360.0f / 10000.0f) * ((int) time);
Matrix.setIdentityM(mModelMatrix, 0);
Matrix.rotateM(mModelMatrix, 0, angleInDegrees, 0.0f, 0.0f, 1.0f);
aBuffer = ByteBuffer.allocateDirect(verts.length * mBytesPerFloat)
.order(ByteOrder.nativeOrder()).asFloatBuffer();
//aBuffer.position(mPositionOffset);
GLES20.glVertexAttribPointer(mPositionHandle, mPositionDataSize, GLES20.GL_FLOAT, false,
mStrideBytes, aBuffer);
GLES20.glEnableVertexAttribArray(mPositionHandle);
// Pass in the color information
aBuffer.position(mColorOffset);
GLES20.glVertexAttribPointer(mColorHandle, mColorDataSize, GLES20.GL_FLOAT, false,
mStrideBytes, aBuffer);
GLES20.glEnableVertexAttribArray(mColorHandle);
// This multiplies the view matrix by the model matrix, and stores the result in the MVP matrix
// (which currently contains model * view).
Matrix.multiplyMM(mMVPMatrix, 0, mViewMatrix, 0, mModelMatrix, 0);
// This multiplies the modelview matrix by the projection matrix, and stores the result in the MVP matrix
// (which now contains model * view * projection).
Matrix.multiplyMM(mMVPMatrix, 0, mProjectionMatrix, 0, mMVPMatrix, 0);
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mMVPMatrix, 0);
GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, 3);
}
工作的代码是：
public void onDrawFrame(GL10 glUnused)
{
GLES20.glClear(GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);
// Do a complete rotation every 10 seconds.
long time = SystemClock.uptimeMillis() % 10000L;
float angleInDegrees = (360.0f / 10000.0f) * ((int) time);
// Draw the triangle facing straight on.
Matrix.setIdentityM(mModelMatrix, 0);
Matrix.rotateM(mModelMatrix, 0, angleInDegrees, 0.0f, 0.0f, 1.0f);
drawTriangle(mTriangle1Vertices);
// Draw one translated a bit down and rotated to be flat on the ground.
Matrix.setIdentityM(mModelMatrix, 0);
Matrix.translateM(mModelMatrix, 0, 0.0f, -1.0f, 0.0f);
Matrix.rotateM(mModelMatrix, 0, 90.0f, 1.0f, 0.0f, 0.0f);
Matrix.rotateM(mModelMatrix, 0, angleInDegrees, 0.0f, 0.0f, 1.0f);
drawTriangle(mTriangle2Vertices);
// Draw one translated a bit to the right and rotated to be facing to the left.
Matrix.setIdentityM(mModelMatrix, 0);
Matrix.translateM(mModelMatrix, 0, 1.0f, 0.0f, 0.0f);
Matrix.rotateM(mModelMatrix, 0, 90.0f, 0.0f, 1.0f, 0.0f);
Matrix.rotateM(mModelMatrix, 0, angleInDegrees, 0.0f, 0.0f, 1.0f);
drawTriangle(mTriangle3Vertices);
*/
/*
for (int x = 0; x < staticHolder.objectList.size(); x++)
{
staticHolder.objectList.get(x).Draw(mViewMatrix, mModelMatrix, mProjectionMatrix, mPositionHandle, mColorHandle, mMVPMatrixHandle);
}
*/
}
/**
* Draws a triangle from the given vertex data.
*
* @param aTriangleBuffer The buffer containing the vertex data.
*/
private void drawTriangle(final FloatBuffer aTriangleBuffer)
{
// Pass in the position information
aTriangleBuffer.position(mPositionOffset);
GLES20.glVertexAttribPointer(mPositionHandle, mPositionDataSize, GLES20.GL_FLOAT, false,
mStrideBytes, aTriangleBuffer);
GLES20.glEnableVertexAttribArray(mPositionHandle);
// Pass in the color information
aTriangleBuffer.position(mColorOffset);
GLES20.glVertexAttribPointer(mColorHandle, mColorDataSize, GLES20.GL_FLOAT, false,
mStrideBytes, aTriangleBuffer);
GLES20.glEnableVertexAttribArray(mColorHandle);
// This multiplies the view matrix by the model matrix, and stores the result in the MVP matrix
// (which currently contains model * view).
Matrix.multiplyMM(mMVPMatrix, 0, mViewMatrix, 0, mModelMatrix, 0);
// This multiplies the modelview matrix by the projection matrix, and stores the result in the MVP matrix
// (which now contains model * view * projection).
Matrix.multiplyMM(mMVPMatrix, 0, mProjectionMatrix, 0, mMVPMatrix, 0);
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mMVPMatrix, 0);
GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, 3);
}
我传入相同的变量，这里使用的最终变量初始化相同。在封装功能中还有其他一些工作要做。知道为什么它拒绝在函数中渲染吗？
以下代码加载列表中的对象：
final float[] triangle1VerticesData = {
// X, Y, Z,
// R, G, B, A
-0.5f, -0.25f, 0.0f,
1.0f, 0.0f, 0.0f, 1.0f,
0.5f, -0.25f, 0.0f,
0.0f, 0.0f, 1.0f, 1.0f,
0.0f, 0.559016994f, 0.0f,
0.0f, 1.0f, 0.0f, 1.0f};
final float[] triangle2VerticesData = {
// X, Y, Z,
// R, G, B, A
-0.5f, -0.25f, 0.0f,
1.0f, 1.0f, 0.0f, 1.0f,
0.5f, -0.25f, 0.0f,
0.0f, 1.0f, 1.0f, 1.0f,
0.0f, 0.559016994f, 0.0f,
1.0f, 0.0f, 1.0f, 1.0f};
// This triangle is white, gray, and black.
final float[] triangle3VerticesData = {
// X, Y, Z,
// R, G, B, A
-0.5f, -0.25f, 0.0f,
1.0f, 1.0f, 1.0f, 1.0f,
0.5f, -0.25f, 0.0f,
0.5f, 0.5f, 0.5f, 1.0f,
0.0f, 0.559016994f, 0.0f,
0.0f, 0.0f, 0.0f, 1.0f};
staticHolder.objectList.add(new Triangle(triangle1VerticesData));
staticHolder.objectList.add(new Triangle(triangle2VerticesData));
staticHolder.objectList.add(new Triangle(triangle3VerticesData));
接收类是：
public class Triangle extends shape
{
public Triangle(float[] data)
{
verts = data;
}
}
答案 0 :(得分：1)
在下面的代码之后：
aBuffer = ByteBuffer.allocateDirect(verts.length * mBytesPerFloat).order(ByteOrder.nativeOrder()).asFloatBuffer();
您必须将顶点放入缓冲区（否则，它是空白的！）：
aBuffer.put(verts);
这不是代码有效的原因，是因为预先分配了这三组顶点的缓冲区，然后将顶点放入其中（初始化时）。它们只是每次传递给方法，因此它们不必再次put()。
在这个注意事项中，您将希望避免在Draw方法中进行分配，因为每帧调用多次并且可能导致渲染速度变慢。分配aBuffer一次，每次都将新顶点放入其中。