我正在使用Java和JOGL实验帧缓冲来创建光晕效果,但是我遇到了问题。目前,我的目标是将我的飞船模型渲染到一个帧缓冲纹理中,并使用一个照明纹理进行贴图,然后将帧缓冲纹理绘制到一个三角形扇形四边形上。我正在使用OpenGL 2.1和/或2.0。以下是生成帧缓冲及其纹理的代码:
private int createFrameBuffer(GL2GL3 gl) {
_frameBufferTextureId = GLHelper.makeTextureBuffer(gl, GL2GL3.GL_RGBA, _width / 2, _height / 2, 0, GL2GL3.GL_RGBA,
GL2GL3.GL_UNSIGNED_BYTE, GL2GL3.GL_TEXTURE_MIN_FILTER, GL2GL3.GL_TEXTURE_MIN_FILTER, GL2GL3.GL_REPEAT, null);
int frameBufferId = GLHelper.makeFrameBuffer(gl, _frameBufferTextureId, _width / 2, _height / 2);
return frameBufferId;
}
public static int makeTextureBuffer(GL2GL3 gl, int glEnumInternalFormat, int width, int height, int border,
int glEnumPixelFormat, int glEnumPixelType, int glEnumMinFilter, int glEnumMagFilter, int glEnumWrapMode,
File textureFile) {
ByteBuffer textureDataBuffer = null;
if (textureFile != null) {
String filePath = textureFile.getPath();
String extension = filePath.substring(filePath.lastIndexOf('.') + 1, filePath.length());
TextureData textureData = null;
try {
textureData = TextureIO.newTextureData(gl.getGLProfile(), textureFile, false, extension);
} catch (IOException e) {
throw new RuntimeException("Error reading texture");
}
textureDataBuffer = getProperlyFormattedBuffer(textureData);
}
IntBuffer texture = IntBuffer.allocate(1);
gl.glGenTextures(1, texture);
gl.glBindTexture(GL2GL3.GL_TEXTURE_2D, texture.get(0));
gl.glTexParameteri(GL2GL3.GL_TEXTURE_2D, GL2GL3.GL_TEXTURE_MIN_FILTER, glEnumMinFilter);
gl.glTexParameteri(GL2GL3.GL_TEXTURE_2D, GL2GL3.GL_TEXTURE_MAG_FILTER, glEnumMagFilter);
gl.glTexParameteri(GL2GL3.GL_TEXTURE_2D, GL2GL3.GL_TEXTURE_WRAP_S, glEnumWrapMode);
gl.glTexParameteri(GL2GL3.GL_TEXTURE_2D, GL2GL3.GL_TEXTURE_WRAP_T, glEnumWrapMode);
gl.glTexImage2D(GL2GL3.GL_TEXTURE_2D, 0, glEnumInternalFormat, width, height, border, glEnumPixelFormat, glEnumPixelType,
textureDataBuffer);
gl.glBindTexture(GL2GL3.GL_TEXTURE_2D, 0);
return texture.get(0);
}
public static int makeFrameBuffer(GL2GL3 gl, int textureBufferId, int width, int height) {
IntBuffer frameBuffer = IntBuffer.allocate(1);
gl.glGenFramebuffers(1, frameBuffer);
gl.glBindFramebuffer(GL2GL3.GL_FRAMEBUFFER, frameBuffer.get(0));
gl.glFramebufferTexture2D(GL2GL3.GL_FRAMEBUFFER, GL2GL3.GL_COLOR_ATTACHMENT0, GL2GL3.GL_TEXTURE_2D, textureBufferId, 0);
verifyFrameBuffer(gl);
gl.glBindFramebuffer(GL2GL3.GL_FRAMEBUFFER, 0);
return frameBuffer.get(0);
}
private void drawTextureQuad(GL2GL3 gl) {
_glowShader.bind(gl);
int textureLocation = _glowShader.getUniformFields().getIlluminationTextureLocation();
gl.glUniform1i(textureLocation, 0);
gl.glActiveTexture(GL2GL3.GL_TEXTURE0);
gl.glBindTexture(GL2GL3.GL_TEXTURE_2D, _frameBufferTextureId);
int vertexLocation = _glowShader.getAttributeFields().getVertexLocation();
gl.glBindBuffer(GL2GL3.GL_ARRAY_BUFFER, _textureQuadId);
gl.glVertexAttribPointer(vertexLocation, 3, GL2GL3.GL_FLOAT, false, 0, 0);
gl.glEnableVertexAttribArray(vertexLocation);
int textureCoordLocation = _glowShader.getAttributeFields().getVertexTextureCoordinateLocation();
gl.glBindBuffer(GL2GL3.GL_ARRAY_BUFFER, _textureQuadCoordsId);
gl.glVertexAttribPointer(textureCoordLocation, 2, GL2GL3.GL_FLOAT, false, 0, 0);
gl.glEnableVertexAttribArray(textureCoordLocation);
gl.glDrawArrays(GL2GL3.GL_TRIANGLE_FAN, 0, 4);
_glowShader.unbind(gl);
}
在我的渲染循环中,我正在执行以下操作:
_glowShader.bind(gl);// bind my Shader object.
gl.glUniformMatrix4fv(_glowShader.getUniformFields().getProjectionMatrixLocation(), 1, true, _projectionMatrix.getBuffer());
gl.glUniformMatrix4fv(_glowShader.getUniformFields().getModelViewMatrixLocation(), 1, true, _modelViewMat.getBuffer());
gl.glBindFramebuffer(GL.GL_FRAMEBUFFER, _framebufferId);
gl.glDrawBuffers(1, _frameBufferAttachmentss); //contains GL_COLOR_ATTACHMENT0
gl.glViewport(0, 0, _width / 2, _height / 2); // same size as texture
_spaceship.draw(gl, _glowShader);// draw method in my ModelObject class
gl.glBindFramebuffer(GL.GL_FRAMEBUFFER, 0);
_glowShader.unbind(gl);
drawTextureQuad(gl);
当我运行这段代码时,我的四元数被正确绘制了,但纹理全部为黑色。当我在渲染循环中注释掉任何帧缓冲绑定时,模型会按预期呈现,因此我知道我的着色器代码没有问题。当我用从文件加载的另一个纹理替换_frameBufferTextureId时,该纹理会被正确绘制,因此我知道我的纹理坐标有效,并且我的着色器代码是正确的。但是每当我绑定我的帧缓冲时,我得不到任何我期望的东西。我也验证了我的帧缓冲,并且它是GL_FRAMEBUFFER_COMPLETE。我已经阅读了无数的教程和stackoverflow上的帖子,但我就是找不出我做错了什么。任何帮助都将不胜感激!谢谢。