Why isn't this Android specular lighting example working as intended?
Why aren't specular highlights showing up in the binary produced by the following code?
package com.example.helloandroid;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
import android.opengl.GLSurfaceView.Renderer;
public class TestRenderer implements Renderer {
private FloatBuffer vb;
private FloatBuffer mab, mdb, msb;
private FloatBuffer lPos;
private FloatBuffer lab, ldb, lsb;
public TestRenderer() {
vb = ByteBuffer.allocateDirect(24 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
vb.put(new float[]{
110.0f, 240.0f,
110.0f, 190.0f,
160.0f, 240.0f,
160.0f, 190.0f,
210.0f, 240.0f,
210.0f, 190.0f,
110.0f, 290.0f,
110.0f, 240.0f,
160.0f, 290.0f,
160.0f, 240.0f,
210.0f, 290.0f,
210.0f, 240.0f});
vb.position(0);
mab = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
mab.put(new float[]{1.0f, 0.0f, 0.0f, 1.0f});
mab.position(0);
mdb = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
mdb.put(new float[]{0.0f, 1.0f, 0.0f, 1.0f});
mdb.position(0);
msb = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()开发者_如何学Python).asFloatBuffer();
msb.put(new float[]{0.0f, 0.0f, 1.0f, 1.0f});
msb.position(0);
lPos = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
lPos.put(new float[]{160.0f, 240.0f, 10.0f, 1.0f});
lPos.position(0);
lab = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
// THIS WORKS..
lab.put(new float[]{0.0f, 0.0f, 0.0f, 1.0f});
lab.position(0);
ldb = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
// SO DOES THIS..
ldb.put(new float[]{0.0f, 0.0f, 0.0f, 1.0f});
ldb.position(0);
// BUT NOT THIS
lsb = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
lsb.put(new float[]{1.0f, 1.0f, 1.0f, 1.0f});
lsb.position(0);
}
@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
gl.glEnable(GL10.GL_LIGHTING);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glMaterialfv(GL10.GL_FRONT, GL10.GL_AMBIENT, mab);
gl.glMaterialfv(GL10.GL_FRONT, GL10.GL_DIFFUSE, mdb);
gl.glMaterialfv(GL10.GL_FRONT, GL10.GL_SPECULAR, msb);
gl.glLightfv(GL10.GL_LIGHT0, GL10.GL_POSITION, lPos);
gl.glLightfv(GL10.GL_LIGHT0, GL10.GL_AMBIENT, lab);
gl.glLightfv(GL10.GL_LIGHT0, GL10.GL_DIFFUSE, ldb);
gl.glLightfv(GL10.GL_LIGHT0, GL10.GL_SPECULAR, lsb);
gl.glEnable(GL10.GL_LIGHT0);
}
@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
gl.glOrthof(0.0f, width, 0.0f, height, -1.0f, 1.0f);
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
gl.glTranslatef(0.0f, 0.0f, -1.0f);
}
@Override
public void onDrawFrame(GL10 gl) {
gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
gl.glVertexPointer(2, GL10.GL_FLOAT, 0, vb);
gl.glNormal3f(0.0f, 0.0f, 1.0f);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 6);
gl.glDrawArrays(GL10.GL_LINE_STRIP, 6, 6);
}
}
Here is what I see from the code as is (with just a specular lighting component): http://i.imgur.com/4kvIx.png
With just an ambient lighting component: http://i.imgur.com/80Tjx.png
With just a diffuse lighting component: http://i.imgur.com/r5PkO.png
Possibly of interest is that the zNear/zFar parameters in my call to glOrtho don't seem to clip anything. Have I properly set up the scene to even view a specular highlight (I did try to position the light near a vertex)?
OpenGL ES only accept GL_FRONT_AND_BACK. See glMaterial here
http://www.khronos.org/opengles/sdk/1.1/docs/man/glMaterial.xml
Well, after banging my head against the wall for a few more hours, I decided on the novel idea of actually running the code on a device instead of just the emulator. Wouldn't you know, after a few tweaks, it seems to work fine!
Here's a new sample with the changes I made and a better scene to illustrate the perceived problem:
package com.example.helloandroid;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
import android.opengl.GLSurfaceView.Renderer;
import android.opengl.GLU;
public class TestRenderer implements Renderer {
private int rows;
private int cols;
private FloatBuffer vb;
private FloatBuffer mab, mdb, msb;
private FloatBuffer lPos;
private FloatBuffer lab, ldb, lsb;
public TestRenderer(int rows, int cols) {
this.rows = rows;
this.cols = cols;
vb = ByteBuffer.allocateDirect(4 * (rows - 1) * cols * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
for(int row = 0; row < (rows - 1); ++row)
for(int col = 0; col < cols; ++col) {
vb.put(col * 320.0f / (cols - 1)); vb.put((row + 1) * 480.0f / (rows - 1));
vb.put(col * 320.0f / (cols - 1)); vb.put(row * 480.0f / (rows - 1));
}
vb.position(0);
// vb = ByteBuffer.allocateDirect(24 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
// vb.put(new float[]{
// 0.0f, 50.0f,
// 0.0f, 0.0f,
// 50.0f, 50.0f,
// 50.0f, 0.0f,
// 100.0f, 50.0f,
// 100.0f, 0.0f,
// 0.0f, 100.0f,
// 0.0f, 50.0f,
// 50.0f, 100.0f,
// 50.0f, 50.0f,
// 100.0f, 100.0f,
// 100.0f, 50.0f});
// vb.position(0);
mab = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
mab.put(new float[]{1.0f, 0.0f, 0.0f, 1.0f});
mab.position(0);
mdb = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
mdb.put(new float[]{0.0f, 1.0f, 0.0f, 1.0f});
mdb.position(0);
msb = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
msb.put(new float[]{0.0f, 0.0f, 1.0f, 1.0f});
msb.position(0);
lPos = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
lPos.put(new float[]{-180.0f, 0.0f, 300.0f, 1.0f});
lPos.position(0);
lab = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
// THIS WORKS..
lab.put(new float[]{0.1f, 0.0f, 0.0f, 1.0f});
lab.position(0);
ldb = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
// SO DOES THIS..
ldb.put(new float[]{0.0f, 0.1f, 0.0f, 1.0f});
ldb.position(0);
// BUT NOT THIS
lsb = ByteBuffer.allocateDirect(4 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
lsb.put(new float[]{0.0f, 0.0f, 1.0f, 1.0f});
lsb.position(0);
}
@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
gl.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
gl.glEnable(GL10.GL_LIGHTING);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glMaterialfv(GL10.GL_FRONT_AND_BACK, GL10.GL_AMBIENT, mab);
gl.glMaterialfv(GL10.GL_FRONT_AND_BACK, GL10.GL_DIFFUSE, mdb);
gl.glMaterialfv(GL10.GL_FRONT_AND_BACK, GL10.GL_SPECULAR, msb);
gl.glMaterialf(GL10.GL_FRONT_AND_BACK, GL10.GL_SHININESS, 128.0f);
gl.glLightfv(GL10.GL_LIGHT0, GL10.GL_POSITION, lPos);
gl.glLightfv(GL10.GL_LIGHT0, GL10.GL_AMBIENT, lab);
gl.glLightfv(GL10.GL_LIGHT0, GL10.GL_DIFFUSE, ldb);
gl.glLightfv(GL10.GL_LIGHT0, GL10.GL_SPECULAR, lsb);
gl.glEnable(GL10.GL_LIGHT0);
gl.glDisable(GL10.GL_TEXTURE);
gl.glFrontFace(GL10.GL_CCW);
}
@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
// gl.glOrthof(0.0f, width, 0.0f, height, -1.0f, 1.0f);
GLU.gluPerspective(gl, 45.0f, (float)width / (float)height, 999.0f, 1001.0f);
gl.glMatrixMode(GL10.GL_MODELVIEW);
}
@Override
public void onDrawFrame(GL10 gl) {
gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
gl.glLoadIdentity();
gl.glTranslatef(-160.0f, -240.0f, -1000.0f);
gl.glVertexPointer(2, GL10.GL_FLOAT, 0, vb);
gl.glNormal3f(0.0f, 0.0f, 1.0f);
for(int row = 0; row < rows - 1; ++row) {
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 2 * row * cols, 2 * cols);
// gl.glDrawArrays(GL10.GL_LINE_STRIP, 2 * row * cols, 2 * cols);
}
// gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 6);
// gl.glDrawArrays(GL10.GL_LINE_STRIP, 6, 6);
}
}
The biggest oddity I ran across is having to switch from GL_FRONT to GL_FRONT_AND_BACK, I have no clue why it wouldn't work with just GL_FRONT (or just GL_BACK, which I also tried in case my winding was backwards or something).
Here's the new sample on the emulator: i.imgur.com/ldAND.png
And on the actual device: i.imgur.com/Ukqqm.png
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