diff options
Diffstat (limited to 'docs/html/training/graphics/opengl/touch.jd')
| -rw-r--r-- | docs/html/training/graphics/opengl/touch.jd | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/docs/html/training/graphics/opengl/touch.jd b/docs/html/training/graphics/opengl/touch.jd index c058a59..4c9f0c7 100644 --- a/docs/html/training/graphics/opengl/touch.jd +++ b/docs/html/training/graphics/opengl/touch.jd @@ -75,7 +75,9 @@ public boolean onTouchEvent(MotionEvent e) { dy = dy * -1 ; } - mRenderer.mAngle += (dx + dy) * TOUCH_SCALE_FACTOR; // = 180.0f / 320 + mRenderer.setAngle( + mRenderer.getAngle() + + ((dx + dy) * TOUCH_SCALE_FACTOR); // = 180.0f / 320 requestRender(); } @@ -123,16 +125,20 @@ add {@code mAngle}, which contains the touch input generated angle:</p> <pre> public void onDrawFrame(GL10 gl) { ... + float[] scratch = new float[16]; + // Create a rotation for the triangle // long time = SystemClock.uptimeMillis() % 4000L; // float angle = 0.090f * ((int) time); <strong>Matrix.setRotateM(mRotationMatrix, 0, mAngle, 0, 0, -1.0f);</strong> // Combine the rotation matrix with the projection and camera view - Matrix.multiplyMM(mMVPMatrix, 0, mRotationMatrix, 0, mMVPMatrix, 0); + // Note that the mMVPMatrix factor *must be first* in order + // for the matrix multiplication product to be correct. + Matrix.multiplyMM(scratch, 0, mMVPMatrix, 0, mRotationMatrix, 0); // Draw triangle - mTriangle.draw(mMVPMatrix); + mTriangle.draw(scratch); } </pre> |