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View Full Version : bloom/blur, rendering to FBO, clearing FBO



Oradon
04-25-2011, 03:03 PM
Hi,

I've been trying to make my own little bloom shaders, and so far it's been working quite well, unfortunately i ran into an issue i really don't know how to fix.

And this is what it looks like:

http://img94.imageshack.us/i/onestepcloserc.png/

As you'd expect from my code (which I will post in a second, these Quads are scaling up and down), only problem is, they lack all color.

This is what they should look like:

http://img121.imageshack.us/i/combineds.png/

At least that's what my shaders used to do until i noticed that i forgot clearing my FBOs, resulting in a non-changeable image.

My guess is I'm missing something obvious, but i cant seem to figure it out.

src:
<div class="ubbcode-block"><div class="ubbcode-header">Click to reveal.. <input type="button" class="form-button" value="Show me!" onclick="toggle_spoiler(this, 'Yikes, my eyes!', 'Show me!')" />]<div style="display: none;">


void testApp::setup(){
ofSetVerticalSync(true);
ofDisableSetupScreen();

width = ofGetWidth();
height = ofGetHeight();

glEnable(GL_DEPTH_TEST);

//complie/link/generate ShaderObjects ....
horizontalBlurFrag.load("/opt/openframeworks/apps/examples/FBO_basic_shader_new_continued_v4_4/bin/data/fragment_shader_horizontal.glsl", GL_FRAGMENT_SHADER);
verticalBlurFrag.load("/opt/openframeworks/apps/examples/FBO_basic_shader_new_continued_v4_4/bin/data/fragment_shader_vertical.glsl", GL_FRAGMENT_SHADER);
BlurVertex.load("/opt/openframeworks/apps/examples/FBO_basic_shader_new_continued_v4_4/bin/data/horizontal_blur.glsl", GL_VERTEX_SHADER);
blendTextures.load("/opt/openframeworks/apps/examples/FBO_basic_shader_new_continued_v4_4/bin/data/blend_shader.glsl", GL_FRAGMENT_SHADER);

fboOriginal.initialize(width, height);
fboH800.initialize(width, height);
fboV800.initialize(width, height);
fboH400.initialize(width, height);
fboV400.initialize(width, height);
}

//--------------------------------------------------------------
void testApp::update(){
time = ofGetElapsedTimef();
}

//--------------------------------------------------------------
void testApp::draw(){
glMatrixMode( GL_PROJECTION );
glLoadIdentity();

//set orthographic projection
glOrtho( -1, 1, -1, 1, 1.0, 40.0 );

glMatrixMode( GL_MODELVIEW );
glLoadIdentity();

glViewport( 0, 0, width, height);

glDisable(GL_TEXTURE_2D);

fboOriginal.bind();

glClearColor(0.0, 0.0, 0.0, 0.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glPushAttrib(GL_VIEWPORT_BIT);
glViewport(0, 0, width, height);
glPushMatrix();
glScalef(0.1f, 0.1f, 1.0f);

//generating values between 0 and 2
float x = 2 * (sin(time)+1.000001)/2;

//drawSOlidRect(xPos, yPos, width, height, red, green, blue);
drawSolidRect(-8.0f, 8.0f, x, x, 0.4f, 0.4f, 1.0f);
drawSolidRect(-5.0f, 8.0f, x, x, 0.4f, 1.0f, 0.4f);
drawSolidRect(-2.0f, 8.0f, x, x, 0.4f, 1.0f, 1.0f);
drawSolidRect( 1.0f, 8.0f, x, x, 1.0f, 0.4f, 0.4f);
drawSolidRect( 4.0f, 8.0f, x, x, 1.0f, 0.4f, 1.0f);
drawSolidRect( 7.0f, 8.0f, x, x, 1.0f, 1.0f, 0.4f);
glPopMatrix();
glPopAttrib();
fboOriginal.unbind();

glEnable(GL_TEXTURE_2D);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, fboOriginal.fboTexture);

BlurVertex.enable();

horizontalBlurFrag.enable();
glUniform1i(glGetUniformLocation(horizontalBlurFra g.program, "RTScene"), 0);

glDisable(GL_TEXTURE_2D);

fboH800.bind();

glClearColor(0.0, 0.0, 0.0, 0.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glPushAttrib(GL_VIEWPORT_BIT);
glViewport(0, 0, width, height);
glPushMatrix();
glBegin(GL_QUADS);
glColor3f(1.0f, 1.0f, 1.0f);

glTexCoord2f(0.0f, 1.0f);
glVertex3f(-1.0, 1.0, -1.0);

glTexCoord2f(1.0f, 1.0f);
glVertex3f(1.0, 1.0, -1.0);

glTexCoord2f(1.0f, 0.0f);
glVertex3f(1.0, -1.0, -1.0);

glTexCoord2f(0.0f, 0.0f);
glVertex3f(-1.0, -1.0, -1.0);
glEnd();
glPopMatrix();
glPopAttrib();
glDisable(GL_TEXTURE_2D);
fboH800.unbind();

glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, fboH800.fboTexture);

BlurVertex.enable();

verticalBlurFrag.enable();
glUniform1i(glGetUniformLocation(verticalBlurFrag. program, "RTBlurH"), 0);

glDisable(GL_TEXTURE_2D);

fboV800.bind();

glClearColor(0.0, 0.0, 0.0, 0.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glPushAttrib(GL_VIEWPORT_BIT);
glViewport(0, 0, width, height);
glPushMatrix();
glBegin(GL_QUADS);
glColor3f(1.0f, 1.0f, 1.0f);

glTexCoord2f(0.0f, 1.0f);
glVertex3f(-1.0, 1.0, -1.0);

glTexCoord2f(1.0f, 1.0f);
glVertex3f(1.0, 1.0, -1.0);

glTexCoord2f(1.0f, 0.0f);
glVertex3f(1.0, -1.0, -1.0);

glTexCoord2f(0.0f, 0.0f);
glVertex3f(-1.0, -1.0, -1.0);
glEnd();
glPopMatrix();
glPopAttrib();
fboV800.unbind();

glEnable(GL_TEXTURE_2D);
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, fboV800.fboTexture);

BlurVertex.enable();

horizontalBlurFrag.enable();
glUniform1i(glGetUniformLocation(horizontalBlurFra g.program, "RTScene"), 1);

glDisable(GL_TEXTURE_2D);

fboH400.bind();

glClearColor(0.0, 0.0, 0.0, 1.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glPushAttrib(GL_VIEWPORT_BIT);
glPushMatrix();
glViewport(0, 0, width/4, height/4); //crude downscale
glBegin(GL_QUADS);
glColor3f(1.0f, 1.0f, 1.0f);

glTexCoord2f(0.0f, 1.0f);
glVertex3f(-1.0, 1.0, -1.0);

glTexCoord2f(1.0f, 1.0f);
glVertex3f(1.0, 1.0, -1.0);

glTexCoord2f(1.0f, 0.0f);
glVertex3f(1.0, -1.0, -1.0);

glTexCoord2f(0.0f, 0.0f);
glVertex3f(-1.0, -1.0, -1.0);
glEnd();
glPopMatrix();
glPopAttrib();
glDisable(GL_TEXTURE_2D);
fboH400.unbind();

glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, fboH400.fboTexture);

BlurVertex.enable();

verticalBlurFrag.enable();
glUniform1i(glGetUniformLocation(verticalBlurFrag. program, "RTBlurH"), 1);

glDisable(GL_TEXTURE_2D);

fboV400.bind();

glClearColor(0.0, 0.0, 0.0, 0.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glPushAttrib(GL_VIEWPORT_BIT);
glPushMatrix();
glViewport(0, 0, width*4, height*4); //crude downscale
glBegin(GL_QUADS);

glColor3f(1.0f, 1.0f, 1.0f);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-1.0, 1.0, -1.0);

glTexCoord2f(1.0f, 1.0f);
glVertex3f(1.0, 1.0, -1.0);

glTexCoord2f(1.0f, 0.0f);
glVertex3f(1.0, -1.0, -1.0);

glTexCoord2f(0.0f, 0.0f);
glVertex3f(-1.0, -1.0, -1.0);
glEnd();
glPopMatrix();
glPopAttrib();
glDisable(GL_TEXTURE_2D);
fboV400.unbind();

glDisable(GL_TEXTURE_2D);

glEnable(GL_TEXTURE_2D);

glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, fboV800.fboTexture);

glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, fboV400.fboTexture);

BlurVertex.enable();

blendTextures.enable();
glUniform1i(glGetUniformLocation(blendTextures.pro gram, "originalSizeTex"), 0);
glUniform1i(glGetUniformLocation(blendTextures.pro gram, "downscaledTex"), 1);

glDisable(GL_TEXTURE_2D);

glBegin(GL_QUADS);

glColor3f(1.0f, 1.0f, 1.0f);
glMultiTexCoord2fARB(GL_TEXTURE0, 0.0f, 1.0f);
glVertex3f(-1.0, 1.0, -1.0);

glMultiTexCoord2fARB(GL_TEXTURE0, 1.0f, 1.0f);
glVertex3f(1.0, 1.0, -1.0);

glMultiTexCoord2fARB(GL_TEXTURE0, 1.0f, 0.0f);
glVertex3f(1.0, -1.0, -1.0);

glMultiTexCoord2fARB(GL_TEXTURE0, 0.0f, 0.0f);
glVertex3f(-1.0, -1.0, -1.0);
glEnd();

glDisable(GL_TEXTURE_2D);
}

[/QUOTE]</div>

fbo:
<div class="ubbcode-block"><div class="ubbcode-header">Click to reveal.. <input type="button" class="form-button" value="Show me!" onclick="toggle_spoiler(this, 'Yikes, my eyes!', 'Show me!')" />]<div style="display: none;">


class FrameBufferObject{
public:
//handles
GLuint fbo, fboTexture, fboDepthbuffer;
public:
void initialize(GLuint width, GLuint height){
// generate namespace for the frame buffer, colorbuffer and depthbuffer
glGenFramebuffersEXT(1, &amp;fbo);
glGenTextures(1, &amp;fboTexture);
glGenRenderbuffersEXT(1, &amp;fboDepthbuffer);

//switch to our fbo so we can bind stuff to it
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo);

//create the colorbuffer texture and attach it to the frame buffer
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, fboTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glGenerateMipmapEXT(GL_TEXTURE_2D);

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,GL_CO LOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, fboTexture, 0);

// create a render buffer as our depthbuffer and attach it
glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, fboDepthbuffer);
glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT24,width, height);
glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, fboDepthbuffer);

// Go back to regular frame buffer rendering
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);

glDisable(GL_TEXTURE_2D);
}

void bind(){
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo);
}
void unbind(){
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
}

void clear(){
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fbo);
glClearColor(0.0, 0.0, 0.0, 0.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
}
};

[/QUOTE]</div>

blend shader:

<div class="ubbcode-block"><div class="ubbcode-header">Click to reveal.. <input type="button" class="form-button" value="Show me!" onclick="toggle_spoiler(this, 'Yikes, my eyes!', 'Show me!')" />]<div style="display: none;">


uniform sampler2D originalSizeTex;
uniform sampler2D downscaledTex;

varying vec2 vTexCoord;

void main(void){
vec4 colorOriginal = vec4(0.0, 0.0, 0.0, 0.0);
vec4 colorDownscale = vec4(0.0, 0.0, 0.0, 0.0);

colorOriginal = texture2D(originalSizeTex, vTexCoord.xy);
colorDownscale = texture2D(downscaledTex, vTexCoord.xy);

gl_FragColor = vec4(colorOriginal + colorDownscale);
}

[/QUOTE]</div>

It's been suggested that there's a problem with the depth testing.

I'd appreciate any suggestions you might have.

dukey
04-26-2011, 03:04 AM
intel graphics card?

Oradon
04-26-2011, 03:31 AM
nVidia GeForce Go 7400