Update hello-gl2 sample to properly implement EGL Config selection.

Also add some comments to explicit what is being done here.
+ add <uses-feature android:glEsVersion="0x00020000"/> to AndroidManifest.xml
This commit is contained in:
David 'Digit' Turner
2010-02-19 17:59:50 -08:00
parent 92210fe14b
commit f4efa044a0
2 changed files with 84 additions and 40 deletions

View File

@@ -32,5 +32,6 @@
</intent-filter>
</activity>
</application>
<uses-feature android:glEsVersion="0x00020000"/>
<uses-sdk android:minSdkVersion="5"/>
</manifest>

View File

@@ -33,6 +33,7 @@ package com.android.gl2jni;
import android.content.Context;
import android.graphics.PixelFormat;
import android.opengl.GLSurfaceView;
import android.util.AttributeSet;
import android.util.Log;
@@ -46,16 +47,26 @@ import javax.microedition.khronos.egl.EGLDisplay;
import javax.microedition.khronos.opengles.GL10;
/**
* An implementation of SurfaceView that uses the dedicated surface for
* displaying an OpenGL animation. This allows the animation to run in a
* separate thread, without requiring that it be driven by the update mechanism
* of the view hierarchy.
* A simple GLSurfaceView sub-class that demonstrate how to perform
* OpenGL ES 2.0 rendering into a GL Surface. Note the following important
* details:
*
* The application-specific rendering code is delegated to a GLView.Renderer
* instance.
* - The class must use a custom context factory to enable 2.0 rendering.
* See ContextFactory class definition below.
*
* - The class must use a custom EGLConfigChooser to be able to select
* an EGLConfig that supports 2.0. This is done by providing a config
* specification to eglChooseConfig() that has the attribute
* EGL10.ELG_RENDERABLE_TYPE containing the EGL_OPENGL_ES2_BIT flag
* set. See ConfigChooser class definition below.
*
* - The class must select the surface's format, then choose an EGLConfig
* that matches it exactly (with regards to red/green/blue/alpha channels
* bit depths). Failure to do so would result in an EGL_BAD_MATCH error.
*/
class GL2JNIView extends GLSurfaceView {
private static String TAG = "GL2JNIView";
private static final boolean DEBUG = false;
public GL2JNIView(Context context) {
super(context);
@@ -68,10 +79,31 @@ class GL2JNIView extends GLSurfaceView {
}
private void init(boolean translucent, int depth, int stencil) {
/* By default, GLSurfaceView() creates a RGB_565 opaque surface.
* If we want a translucent one, we should change the surface's
* format here, using PixelFormat.TRANSLUCENT for GL Surfaces
* is interpreted as any 32-bit surface with alpha by SurfaceFlinger.
*/
if (translucent) {
this.getHolder().setFormat(PixelFormat.TRANSLUCENT);
}
/* Setup the context factory for 2.0 rendering.
* See ContextFactory class definition below
*/
setEGLContextFactory(new ContextFactory());
/* We need to choose an EGLConfig that matches the format of
* our surface exactly. This is going to be done in our
* custom config chooser. See ConfigChooser class definition
* below.
*/
setEGLConfigChooser( translucent ?
new ConfigChooser(8,8,8,8, depth, stencil) :
new ConfigChooser(5,6,5,0, depth, stencil));
new ConfigChooser(8, 8, 8, 8, depth, stencil) :
new ConfigChooser(5, 6, 5, 0, depth, stencil) );
/* Set the renderer responsible for frame rendering */
setRenderer(new Renderer());
}
@@ -99,15 +131,6 @@ class GL2JNIView extends GLSurfaceView {
}
private static class ConfigChooser implements GLSurfaceView.EGLConfigChooser {
private static int EGL_OPENGL_ES2_BIT = 4;
private static int[] s_configAttribs2 =
{
EGL10.EGL_RED_SIZE, 4,
EGL10.EGL_GREEN_SIZE, 4,
EGL10.EGL_BLUE_SIZE, 4,
EGL10.EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
EGL10.EGL_NONE
};
public ConfigChooser(int r, int g, int b, int a, int depth, int stencil) {
mRedSize = r;
@@ -118,8 +141,24 @@ class GL2JNIView extends GLSurfaceView {
mStencilSize = stencil;
}
/* This EGL config specification is used to specify 2.0 rendering.
* We use a minimum size of 4 bits for red/green/blue, but will
* perform actual matching in chooseConfig() below.
*/
private static int EGL_OPENGL_ES2_BIT = 4;
private static int[] s_configAttribs2 =
{
EGL10.EGL_RED_SIZE, 4,
EGL10.EGL_GREEN_SIZE, 4,
EGL10.EGL_BLUE_SIZE, 4,
EGL10.EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
EGL10.EGL_NONE
};
public EGLConfig chooseConfig(EGL10 egl, EGLDisplay display) {
/* Get the number of minimally matching EGL configurations
*/
int[] num_config = new int[1];
egl.eglChooseConfig(display, s_configAttribs2, null, 0, num_config);
@@ -128,41 +167,46 @@ class GL2JNIView extends GLSurfaceView {
if (numConfigs <= 0) {
throw new IllegalArgumentException("No configs match configSpec");
}
/* Allocate then read the array of minimally matching EGL configs
*/
EGLConfig[] configs = new EGLConfig[numConfigs];
egl.eglChooseConfig(display, s_configAttribs2, configs, numConfigs, num_config);
// printConfigs(egl, display, configs);
if (DEBUG) {
printConfigs(egl, display, configs);
}
/* Now return the "best" one
*/
return chooseConfig(egl, display, configs);
}
public EGLConfig chooseConfig(EGL10 egl, EGLDisplay display,
EGLConfig[] configs) {
EGLConfig closestConfig = null;
int closestDistance = 1000;
for(EGLConfig config : configs) {
int d = findConfigAttrib(egl, display, config,
EGL10.EGL_DEPTH_SIZE, 0);
int s = findConfigAttrib(egl, display, config,
EGL10.EGL_STENCIL_SIZE, 0);
if (d >= mDepthSize && s>= mStencilSize) {
int r = findConfigAttrib(egl, display, config,
EGL10.EGL_RED_SIZE, 0);
int g = findConfigAttrib(egl, display, config,
EGL10.EGL_GREEN_SIZE, 0);
int b = findConfigAttrib(egl, display, config,
EGL10.EGL_BLUE_SIZE, 0);
int a = findConfigAttrib(egl, display, config,
EGL10.EGL_ALPHA_SIZE, 0);
int distance = Math.abs(r - mRedSize)
+ Math.abs(g - mGreenSize)
+ Math.abs(b - mBlueSize)
+ Math.abs(a - mAlphaSize);
if (distance < closestDistance) {
closestDistance = distance;
closestConfig = config;
}
}
// We need at least mDepthSize and mStencilSize bits
if (d < mDepthSize || s < mStencilSize)
continue;
// We want an *exact* match for red/green/blue/alpha
int r = findConfigAttrib(egl, display, config,
EGL10.EGL_RED_SIZE, 0);
int g = findConfigAttrib(egl, display, config,
EGL10.EGL_GREEN_SIZE, 0);
int b = findConfigAttrib(egl, display, config,
EGL10.EGL_BLUE_SIZE, 0);
int a = findConfigAttrib(egl, display, config,
EGL10.EGL_ALPHA_SIZE, 0);
if (r == mRedSize && g == mGreenSize && b == mBlueSize && a == mAlphaSize)
return config;
}
return closestConfig;
return null;
}
private int findConfigAttrib(EGL10 egl, EGLDisplay display,
@@ -293,4 +337,3 @@ class GL2JNIView extends GLSurfaceView {
}
}
}