GLSL, reading wrong value inside a fragment shader for a bounded depth texture - jogl

Question

I am applying a slightly modified version of the classic depth peeling algorithm, basically I am rendering all the opaque objects first and then I use that depth as minimum depth, because since they are opaque, it doesnt make sense to not discard fragment deeper than them.
I first tested it on a small test case and it works flawless.
Now I am applying this algorithm to my main application, but for some unknown reasons, it doesnt work and I am going crazy, the main problem is that I keep reading the value 0 for the opaque depth texture bounded in the fragment shader of the next stage
To sum up, this is the fbo for the opaque stuff:
opaqueDepthTexture = new int[1];
opaqueColorTexture = new int[1];
opaqueFbo = new int[1];
gl3.glGenTextures(1, opaqueDepthTexture, 0);
gl3.glGenTextures(1, opaqueColorTexture, 0);
gl3.glGenFramebuffers(1, opaqueFbo, 0);
gl3.glBindTexture(GL3.GL_TEXTURE_RECTANGLE, opaqueDepthTexture[0]);
gl3.glTexImage2D(GL3.GL_TEXTURE_RECTANGLE, 0, GL3.GL_DEPTH_COMPONENT32F, width, height, 0,
GL3.GL_DEPTH_COMPONENT, GL3.GL_FLOAT, null);
gl3.glTexParameteri(GL3.GL_TEXTURE_RECTANGLE, GL3.GL_TEXTURE_BASE_LEVEL, 0);
gl3.glTexParameteri(GL3.GL_TEXTURE_RECTANGLE, GL3.GL_TEXTURE_MAX_LEVEL, 0);
gl3.glBindTexture(GL3.GL_TEXTURE_RECTANGLE, opaqueColorTexture[0]);
gl3.glTexImage2D(GL3.GL_TEXTURE_RECTANGLE, 0, GL3.GL_RGBA, width, height, 0,
GL3.GL_RGBA, GL3.GL_FLOAT, null);
gl3.glTexParameteri(GL3.GL_TEXTURE_RECTANGLE, GL3.GL_TEXTURE_BASE_LEVEL, 0);
gl3.glTexParameteri(GL3.GL_TEXTURE_RECTANGLE, GL3.GL_TEXTURE_MAX_LEVEL, 0);
gl3.glBindFramebuffer(GL3.GL_FRAMEBUFFER, opaqueFbo[0]);
gl3.glFramebufferTexture2D(GL3.GL_FRAMEBUFFER, GL3.GL_DEPTH_ATTACHMENT, GL3.GL_TEXTURE_RECTANGLE,
opaqueDepthTexture[0], 0);
gl3.glFramebufferTexture2D(GL3.GL_FRAMEBUFFER, GL3.GL_COLOR_ATTACHMENT0, GL3.GL_TEXTURE_RECTANGLE,
opaqueColorTexture[0], 0);
checkBindedFrameBuffer(gl3);
Here I just clear the depth (default to 1), I even commented out the opaque rendering:
/**
* (1) Initialize Opaque FBO.
*/
gl3.glBindFramebuffer(GL3.GL_FRAMEBUFFER, opaqueFbo[0]);
gl3.glDrawBuffer(GL3.GL_COLOR_ATTACHMENT0);
gl3.glClearColor(1, 1, 1, 1);
gl3.glClear(GL3.GL_COLOR_BUFFER_BIT | GL3.GL_DEPTH_BUFFER_BIT);
gl3.glEnable(GL3.GL_DEPTH_TEST);
dpOpaque.bind(gl3);
{
// EC_Graph.instance.getRoot().renderDpOpaque(gl3, dpOpaque, new MatrixStack(), properties);
}
dpOpaque.unbind(gl3);
And I have a double confirmation from this
FloatBuffer fb = FloatBuffer.allocate(1 * GLBuffers.SIZEOF_FLOAT);
gl3.glReadPixels(width / 2, height / 2, 1, 1, GL3.GL_DEPTH_COMPONENT, GL3.GL_FLOAT, fb);
System.out.println("opaque fb.get(0) " + fb.get(0));
If I change the clearDepth to 0.9 for example, I get 0.9, so this is ok.
Now I initialize the minimum depth buffer, by rendering all the geometry having alpha < 1 and I bind the previous depth texture, the one used in the opaque rendering, to the
uniform sampler2D opaqueDepthTexture;
I temporarily switched the rendering of this passage to the default framebuffer
/**
* (2) Initialize Min Depth Buffer.
*/
gl3.glBindFramebuffer(GL3.GL_FRAMEBUFFER, 0);
gl3.glDrawBuffer(GL3.GL_BACK);
// gl3.glBindFramebuffer(GL3.GL_FRAMEBUFFER, blendFbo[0]);
// gl3.glDrawBuffer(GL3.GL_COLOR_ATTACHMENT0);
gl3.glClearColor(0, 0, 0, 1);
gl3.glClear(GL3.GL_COLOR_BUFFER_BIT | GL3.GL_DEPTH_BUFFER_BIT);
gl3.glEnable(GL3.GL_DEPTH_TEST);
if (cullFace) {
gl3.glEnable(GL3.GL_CULL_FACE);
}
dpInit.bind(gl3);
{
gl3.glActiveTexture(GL3.GL_TEXTURE1);
gl3.glBindTexture(GL3.GL_TEXTURE_RECTANGLE, opaqueDepthTexture[0]);
gl3.glUniform1i(dpInit.getOpaqueDepthTextureUL(), 1);
gl3.glBindSampler(1, sampler[0]);
{
EC_Graph.instance.getRoot().renderDpTransparent(gl3, dpInit, new MatrixStack(), properties);
}
gl3.glBindTexture(GL3.GL_TEXTURE_RECTANGLE, 0);
gl3.glBindSampler(1, 0);
}
dpInit.unbind(gl3);
This is the dpInit Fragment Shader:
#version 330
out vec4 outputColor;
uniform sampler2D texture0;
in vec2 oUV;
uniform sampler2D opaqueDepthTexture;
/*
* Layout {lighting, normal orientation, active, selected}
*/
uniform ivec4 settings;
const vec3 selectionColor = vec3(1, .5, 0);
const vec4 inactiveColor = vec4(.5, .5, .5, .2);
vec4 CalculateLight();
void main()
{
float opaqueDepth = texture(opaqueDepthTexture, gl_FragCoord.xy).r;
if(gl_FragCoord.z > opaqueDepth) {
//discard;
}
vec4 color = (1 - settings.x) * texture(texture0, oUV) + settings.x * CalculateLight();
if(settings.w == 1) {
if(settings.z == 1) {
color = vec4(selectionColor, color.q);
} else {
color = vec4(selectionColor, inactiveColor.w);
}
} else {
if(settings.z == 0) {
color = inactiveColor;
}
}
outputColor = vec4(color.rgb * color.a, 1.0 - color.a);
outputColor = vec4(.5, 1, 1, 1.0 - color.a);
if(opaqueDepth == 0)
outputColor = vec4(1, 0, 0, 1);
else
outputColor = vec4(0, 1, 0, 1);
}
Ignore the middle, the important is just at the begin, where I read the red component of the previous depth texture and then I compare at the end, and the geometry I obtain is red, this means the value I read in the opaqueDepthTexture is 0...
The question is why?
After the dpInit rendering, if I bind again the opaqueFbo and read the depth, it is always the clearDepth, so 1 as default or .9 if I cleared it with .9, so it works.
The problem is really that I read the wrong value in the dpInit FS from a bound depth texture.. why?
For clarification, this is the sampler:
private void initSampler(GL3 gl3) {
sampler = new int[1];
gl3.glGenSamplers(1, sampler, 0);
gl3.glSamplerParameteri(sampler[0], GL3.GL_TEXTURE_WRAP_S, GL3.GL_CLAMP_TO_EDGE);
gl3.glSamplerParameteri(sampler[0], GL3.GL_TEXTURE_WRAP_T, GL3.GL_CLAMP_TO_EDGE);
gl3.glSamplerParameteri(sampler[0], GL3.GL_TEXTURE_MIN_FILTER, GL3.GL_NEAREST);
gl3.glSamplerParameteri(sampler[0], GL3.GL_TEXTURE_MAG_FILTER, GL3.GL_NEAREST);
}
Ps: checking all the components, I see the opaqueDepthTexture has always the following values (0, 0, 0, 1)

Answer 1

Oh god, I found it, in the init FS
uniform sampler2D opaqueDepthTexture;
should be
uniform sampler2DRect opaqueDepthTexture;