问题
I'm trying to render to a texture (really thought it would be easier than this!)
I found this resource: which seems to be exactly what I want
I'm getting a ClassCastException however, on GL11ExtensionPack gl11ep = (GL11ExtensionPack) gl;
Can anyone tell me why?
public void renderToTexture(GLRenderer glRenderer, GL10 gl)
{
boolean checkIfContextSupportsExtension = checkIfContextSupportsExtension(gl, "GL_OES_framebuffer_object");
if(checkIfContextSupportsExtension)
{
GL11ExtensionPack gl11ep = (GL11ExtensionPack) gl;
int mFrameBuffer = createFrameBuffer(gl,texture.getWidth(), texture.getHeight(), texture.getGLID());
gl11ep.glBindFramebufferOES(GL11ExtensionPack.GL_FRAMEBUFFER_OES, mFrameBuffer);
gl.glClearColor(0f, 1f, 0f, 1f);
gl11ep.glBindFramebufferOES(GL11ExtensionPack.GL_FRAMEBUFFER_OES, 0);
}
}
Issue fixed by removing setDebugFlags(GLSurfaceView.DEBUG_LOG_GL_CALLS);
However, its still not modifying the texture. I modified the code so all it does is clear the colour green, so the texture should become all green. Here is the createFrameBuffer method. I don't really understand everything thats going on in this :/
private int createFrameBuffer(GL10 gl, int width, int height, int targetTextureId) {
GL11ExtensionPack gl11ep = (GL11ExtensionPack) gl;
int framebuffer;
int[] framebuffers = new int[1];
gl11ep.glGenFramebuffersOES(1, framebuffers, 0);
framebuffer = framebuffers[0];
gl11ep.glBindFramebufferOES(GL11ExtensionPack.GL_FRAMEBUFFER_OES, framebuffer);
int depthbuffer;
int[] renderbuffers = new int[1];
gl11ep.glGenRenderbuffersOES(1, renderbuffers, 0);
depthbuffer = renderbuffers[0];
gl11ep.glBindRenderbufferOES(GL11ExtensionPack.GL_RENDERBUFFER_OES, depthbuffer);
gl11ep.glRenderbufferStorageOES(GL11ExtensionPack.GL_RENDERBUFFER_OES,
GL11ExtensionPack.GL_DEPTH_COMPONENT16, width, height);
gl11ep.glFramebufferRenderbufferOES(GL11ExtensionPack.GL_FRAMEBUFFER_OES,
GL11ExtensionPack.GL_DEPTH_ATTACHMENT_OES,
GL11ExtensionPack.GL_RENDERBUFFER_OES, depthbuffer);
gl11ep.glFramebufferTexture2DOES(GL11ExtensionPack.GL_FRAMEBUFFER_OES,
GL11ExtensionPack.GL_COLOR_ATTACHMENT0_OES, GL10.GL_TEXTURE_2D,
targetTextureId, 0);
int status = gl11ep.glCheckFramebufferStatusOES(GL11ExtensionPack.GL_FRAMEBUFFER_OES);
if (status != GL11ExtensionPack.GL_FRAMEBUFFER_COMPLETE_OES) {
//throw new RuntimeException("Framebuffer is not complete: " +
// Integer.toHexString(status));
Log.v("error","Frame buffer not complete");
} else {
gl11ep.glBindFramebufferOES(GL11ExtensionPack.GL_FRAMEBUFFER_OES, 0);
return -1;
}
return framebuffer;
}
回答1:
Calling setDebugFlags
on a GLSurfaceView
to wrap the GL instance has/had the unfortunate sideeffect to not implementing all GL* interfaces. Unfortunately the issue does not state in which version this is fixed.
来源:https://stackoverflow.com/questions/9969163/classcaseexception-on-gl11extensionpack-rendering-to-texture-on-opengl-android