public void onDrawFrame(GL10 gl) {
/*
* By default, OpenGL enables features that improve quality
* but reduce performance. One might want to tweak that
* especially on software renderer.
*/
glDisable(GL_DITHER);
glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
/*
* Usually, the first thing one might want to do is to clear
* the screen. The most efficient way of doing this is to use
* glClear().
*/
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
/*
* Now we're ready to draw some 3D objects
*/
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
GLU.gluLookAt(gl, 0, 0, -5, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, mTextureID);
glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
long time = SystemClock.uptimeMillis() % 4000L;
float angle = 0.090f * ((int) time);
glRotatef(angle, 0, 0, 1.0f);
mTriangle.draw(gl);
}
/**
* Draws a frame where the content of the electron beam is collapsing inwards upon itself
* vertically with red / green / blue channels dispersing and eventually merging down to a single
* horizontal line.
*
* @param stretch The stretch factor. 0.0 is no collapse, 1.0 is full collapse.
*/
private void drawVStretch(float stretch) {
// compute interpolation scale factors for each color channel
final float ar = scurve(stretch, 7.5f);
final float ag = scurve(stretch, 8.0f);
final float ab = scurve(stretch, 8.5f);
if (DEBUG) {
Slog.d(TAG, "drawVStretch: stretch=" + stretch + ", ar=" + ar + ", ag=" + ag + ", ab=" + ab);
}
// set blending
GLES10.glBlendFunc(GLES10.GL_ONE, GLES10.GL_ONE);
GLES10.glEnable(GLES10.GL_BLEND);
// bind vertex buffer
GLES10.glVertexPointer(2, GLES10.GL_FLOAT, 0, mVertexBuffer);
GLES10.glEnableClientState(GLES10.GL_VERTEX_ARRAY);
// set-up texturing
GLES10.glDisable(GLES10.GL_TEXTURE_2D);
GLES10.glEnable(GLES11Ext.GL_TEXTURE_EXTERNAL_OES);
// bind texture and set blending for drawing planes
GLES10.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, mTexNames[0]);
GLES10.glTexEnvx(
GLES10.GL_TEXTURE_ENV,
GLES10.GL_TEXTURE_ENV_MODE,
mMode == MODE_WARM_UP ? GLES10.GL_MODULATE : GLES10.GL_REPLACE);
GLES10.glTexParameterx(
GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES10.GL_TEXTURE_MAG_FILTER, GLES10.GL_LINEAR);
GLES10.glTexParameterx(
GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES10.GL_TEXTURE_MIN_FILTER, GLES10.GL_LINEAR);
GLES10.glTexParameterx(
GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES10.GL_TEXTURE_WRAP_S, GLES10.GL_CLAMP_TO_EDGE);
GLES10.glTexParameterx(
GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES10.GL_TEXTURE_WRAP_T, GLES10.GL_CLAMP_TO_EDGE);
GLES10.glEnable(GLES11Ext.GL_TEXTURE_EXTERNAL_OES);
GLES10.glTexCoordPointer(2, GLES10.GL_FLOAT, 0, mTexCoordBuffer);
GLES10.glEnableClientState(GLES10.GL_TEXTURE_COORD_ARRAY);
// draw the red plane
setVStretchQuad(mVertexBuffer, mDisplayWidth, mDisplayHeight, ar, mSwapNeeded);
GLES10.glColorMask(true, false, false, true);
GLES10.glDrawArrays(GLES10.GL_TRIANGLE_FAN, 0, 4);
// draw the green plane
setVStretchQuad(mVertexBuffer, mDisplayWidth, mDisplayHeight, ag, mSwapNeeded);
GLES10.glColorMask(false, true, false, true);
GLES10.glDrawArrays(GLES10.GL_TRIANGLE_FAN, 0, 4);
// draw the blue plane
setVStretchQuad(mVertexBuffer, mDisplayWidth, mDisplayHeight, ab, mSwapNeeded);
GLES10.glColorMask(false, false, true, true);
GLES10.glDrawArrays(GLES10.GL_TRIANGLE_FAN, 0, 4);
// clean up after drawing planes
GLES10.glDisable(GLES11Ext.GL_TEXTURE_EXTERNAL_OES);
GLES10.glDisableClientState(GLES10.GL_TEXTURE_COORD_ARRAY);
GLES10.glColorMask(true, true, true, true);
// draw the white highlight (we use the last vertices)
if (mMode == MODE_COOL_DOWN) {
GLES10.glColor4f(ag, ag, ag, 1.0f);
GLES10.glDrawArrays(GLES10.GL_TRIANGLE_FAN, 0, 4);
}
// clean up
GLES10.glDisableClientState(GLES10.GL_VERTEX_ARRAY);
GLES10.glDisable(GLES10.GL_BLEND);
}