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最终目标是使用乒乓方法将两个纹理附加到相同的帧缓冲区，从而实现GPU图像处理（色彩量化，像素排序，连通分量分析）。AIDE-ide中的opengl es 3.0 - 渲染纹理返回空白纹理
我看了其他线程，完成了我的纹理，检查了错误，后面跟着this教程和that教程，看了一下文档，但是没有任何东西可以工作。我可以渲染到屏幕上，但我可以渲染到附加到帧缓冲区的纹理。
我知道绘制到四边形作品的代码，因为我对两种类型的渲染都使用相同的代码。我没有得到glCheckFramebufferStatus或glGetErrors的错误，并且eveything看起来就像在教程中一样，期望我创建或附加了渲染缓冲区，因为我不需要深度或模板数据。所以我很茫然。任何帮助将非常感谢，所以我可以继续努力找出困难的东西。
代码创建帧缓存和纹理，并检查错误，在ImageRenderer类：
public static int createFBO()
{
int[] fbo = new int[1];
GLES30.glGenFramebuffers(1,fbo,0);
GLES30.glBindFramebuffer(GLES30.GL_FRAMEBUFFER, fbo[0]);
int error = GLES30.glGetError();
if(error != GLES30.GL_NO_ERROR)
{
while (error !=GLES30.GL_NO_ERROR)
{
System.out.println(error);
error = GLES30.glGetError();
}
GLES30.glBindFramebuffer(GLES30.GL_FRAMEBUFFER, 0);
return 0;
}
else
{
GLES30.glBindFramebuffer(GLES30.GL_FRAMEBUFFER, 0);
return fbo[0];
}
}
public static int[] createFBOTextures(int framebuffer, int width, int height)
{
//bind the framebuffer
GLES30.glBindFramebuffer(GLES30.GL_FRAMEBUFFER, framebuffer);
int[] rt = new int[2];
GLES30.glGenTextures(2, rt, 0);
int[] DrawBuffers = {GLES30.GL_COLOR_ATTACHMENT0,GLES30.GL_COLOR_ATTACHMENT1};
for (int i=0; i<2; i++)
{
GLES30.glBindTexture(GLES30.GL_TEXTURE_2D, rt[i]);
GLES30.glTexImage2D(GLES30.GL_TEXTURE_2D,0,GLES30.GL_RGBA32F, width, height,0,GLES30.GL_RGBA, GLES30.GL_FLOAT, null);
GLES30.glTexParameterf(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_MAG_FILTER, GLES30.GL_LINEAR);
GLES30.glTexParameterf(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_MIN_FILTER, GLES30.GL_LINEAR_MIPMAP_LINEAR);
GLES30.glTexParameterf(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_WRAP_S, GLES30.GL_CLAMP_TO_EDGE);
GLES30.glTexParameterf(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_WRAP_T, GLES30.GL_CLAMP_TO_EDGE);
// Attach each texture to colour attachement #i
GLES30.glFramebufferTexture2D (GLES30.GL_FRAMEBUFFER, DrawBuffers[i], GLES30.GL_TEXTURE_2D, rt[i], 0);
}
if(check_framebuffer_errors())
return null;
else
return rt;
}
public static boolean check_framebuffer_errors()
{
if(GLES30.glCheckFramebufferStatus(GLES30.GL_FRAMEBUFFER) != GLES30.GL_FRAMEBUFFER_COMPLETE)
{
System.out.println(GLES30.glCheckFramebufferStatus(GLES30.GL_FRAMEBUFFER));
return true;
}
else
{
int error = GLES30.glGetError();
if(error !=GLES30.GL_NO_ERROR)
{
while (error != GLES30.GL_NO_ERROR)
{
System.out.println(error);
error = GLES30.glGetError();
}
return true;
}
else
return false;
}
}
所有借鉴PixelCounter对象进行的命令，像这样初始化：
public PixelCounter(Bitmap b)
{
mWidth = b.getWidth();
mHeight = b.getHeight();
defineShape();
ConversionData = ImageRenderer.createUBO(16+3);
ImageRenderer.updateBuffer(toXYZ,0,ConversionData);
ImageRenderer.updateBuffer(new float[]{0.95047f, 1.0f, 1.08883f},15,ConversionData);
FBOHandle = ImageRenderer.createFBO();
//create temporary texture to pass bitmap to float texture
temptex = ImageRenderer.loadTexturefromBitmap(b);
//create ping-pong textures
FBOTextureHandles = ImageRenderer.createFBOTextures(FBOHandle, mWidth,mHeight);
to_LAB = compile_shader(new String[]{default_vertex,to_lab});
to_screen = compile_shader(new String[]{default_vertex, render_to_screen});
to_texture = compile_shader(new String[]{default_vertex, render_to_texture});
}
代码绘制四
//draw temptex to initial src texture
GLES30.glBindFramebuffer(GLES30.GL_FRAMEBUFFER,FBOHandle);
GLES30.glClear(GLES30.GL_COLOR_BUFFER_BIT | GLES30.GL_DEPTH_BUFFER_BIT);
//GLES30.glViewport(0,0,mWidth,mHeight);
bindTexture(temptex, to_texture, "src");
GLES30.glDrawBuffers(1, new int[]{GLES30.GL_COLOR_ATTACHMENT0}, 0);
simple_draw(to_texture);
//draw to screen
GLES30.glBindFramebuffer(GLES30.GL_FRAMEBUFFER,0);
bindTexture(FBOTextureHandles[dest],to_screen, "src");
simple_draw(to_screen);
simple_draw函数
private void simple_draw(int program)
{
GLES30.glUseProgram(program);
//get handle to vertex shader's position member
mPositionHandle = GLES30.glGetAttribLocation(program, "position");
//Add attribute array of vertices
GLES30.glEnableVertexAttribArray(mPositionHandle);
GLES30.glVertexAttribPointer(
mPositionHandle, mPositionDataSize,
GLES30.GL_FLOAT, false,
mStrideBytes, vertexBuffer);
GLES30.glDrawElements(
GLES30.GL_TRIANGLES, drawOrder.length,
GLES30.GL_UNSIGNED_SHORT, drawListBuffer);
}
我的好措施片段着色器：
private String render_to_texture =
"#version 300 es \n" +
"uniform sampler2D src;\n"+
"in vec4 coord;\n"+
"layout(location = 0) out vec4 dest;\n" +
"void main()\n"+
"{\n"+
"vec2 size = vec2(textureSize(src,0));\n"+
"ivec2 uv_coord = ivec2((coord.xy+vec2(1.0,1.0))/2.0*size);\n"+
"dest = texelFetch(src,uv_coord,0);\n"+
"}";