Community Core Vision (Beta)

/*

*  GPUImageFilter.cpp

*  

*

*  Created on 2/2/09.

*  Copyright 2009 NUI Group. All rights reserved.

*

*/

#include "GPUImageFilter.h"

#include <stdio.h>

#include "tinyxml.h"

#include "ofUtils.h"

//helper functon, should go somewhere else

void getFrameBufferForTexture(GLuint* fbo, GLuint* tex, int sizeX, int sizeY){

    GLenum status;

    //allocate ouput buffer on GPU using FBO

    glEnable(GL_TEXTURE_2D);

    glGenTextures(1, tex);

    glBindTexture(GL_TEXTURE_2D, *tex);

    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8,  sizeX, sizeY, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);

    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);

    glTexParameterf(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);

    glBindTexture(GL_TEXTURE_2D, 0);

    //generate fbo

    glGenFramebuffersEXT(1, fbo);

    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, *fbo);

    //attach texture to fbo

    glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, *tex, 0);

    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);

    status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);

    printf("Frame buffer status: %d\n", status);

}

GPUImageFilter::GPUImageFilter(const char* fname, int sx, int sy){

//read the filter description file and creates a filter based on the shaders and parameters given in that file

//allocates output buffer/texture

        res_x = sx; res_y = sy;

        useGeometryShader =false;

        //this->shader = shaderProg;

        glGenTextures(1, &output_texture );

        getFrameBufferForTexture(&output_buffer, &output_texture, res_x, res_y);

        this->parseXML(fname);

}

void GPUImageFilter::parseXML(const char* fname){

        //load filter description file

        printf("Loading Filter...\n");

        //load and parse xml filter description file

        TiXmlDocument doc(ofToDataPath(fname).c_str());

        if (!doc.LoadFile()) printf("error loading filter description file");

        //get the name of the filter

        TiXmlElement* root_node = doc.RootElement();

        this->name = root_node->Attribute("name");

        printf("Filter Name:%s\n", this->name);

        //get the  shader source file names

        TiXmlElement* node = root_node;

        node = root_node->FirstChildElement("VertexShader");

        const char* vertSrc = node ? node->GetText() : NULL;

        node = root_node->FirstChildElement("GeometryShader");

        const char* geomSrc = node ? node->GetText() : NULL;

        if (geomSrc != NULL){ //We are using a geometry shader

                this->useGeometryShader = true;

        }

        node = root_node->FirstChildElement("FragmentShader");

        const char* fragSrc = node ? node->GetText() : NULL;

    this->shader = new ShaderProgram(vertSrc, geomSrc, ofToDataPath(fragSrc).c_str());

        //get parameters

        //TODO: add type handling

        while( (node = (TiXmlElement*)node->NextSibling("Parameter")) ){

                const char* name = node->Attribute("name");

                float type = atof(node->Attribute("type"));

                float min = atof(node->Attribute("min"));

                float max = atof(node->Attribute("max"));

                float val = atof(node->GetText());

                parameters["size_cx"] = new FilterParameter("size_cx", (float)res_x, 0, 0, 0 );

                parameters["size_cy"] = new FilterParameter("size_cy", (float)res_y, 0, 0, 0 );

                parameters[std::string(name)] = new FilterParameter(name, val, min, max, (int)type );

        }

}

//applies the filter to a GL texture.

//

//saves opengl states, and binds this filter's output buffer (render to texture)

//sets up ortho projection for drawing just the texture using teh filters shaders

//parameters are set as uniforms for the shaders

GLuint GPUImageFilter::apply(GLuint inputTexture, GLuint inputTexture2){

        glPushAttrib(GL_VIEWPORT_BIT);

    glPushAttrib(GL_ENABLE_BIT);

    glMatrixMode(GL_MODELVIEW);

    glPushMatrix();

    glMatrixMode(GL_PROJECTION);

    glPushMatrix();

    //render to the fbo using the shader

    glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, output_buffer);

    glClearColor(0.0,1.0,0.0,1.0);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glViewport(0,0,res_x, res_y);

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    glOrtho(-1, 1.0, -1, 1.0, -1, 1.0);

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity();

        glEnable(GL_TEXTURE_2D);

    glBindTexture(GL_TEXTURE_2D, inputTexture);

    this->shader->enable();

    //set the parameters for the filters

        for(std::map<std::string, FilterParameter*>::const_iterator it = parameters.begin(); it != parameters.end(); ++it){

                    const char* test = it->first.c_str();

                float test2 = it->second->value;

                        this->shader->setUniform1f(it->first.c_str(), it->second->value);

        }

        if (inputTexture2 !=0){

                this->shader->setUniform1i("tex2", 1);

        }

        //use geometry shader threads to process image blocks

        if(useGeometryShader){

                        //send n number of threads

                int numThreads = (int) parameters["threads"]->value;

                        glBegin(GL_POINTS);

                //glVertex2d(3,3);

                int i=0;

                for(i=0; i<numThreads; i++){

                                float x = (float)((i/numThreads ) / (float)numThreads -0.5f) * 2.0f;

                                float y = (float)((i%numThreads ) / (float)numThreads  -0.5f)* 2.0f;

                                glVertex2d(x,y);

                }

                        glEnd();

        }else{

                //draw full screen quad with input texture aplied

                glActiveTexture(GL_TEXTURE0);

                glEnable(GL_TEXTURE_2D);

        glBindTexture(GL_TEXTURE_2D, inputTexture);

                glActiveTexture(GL_TEXTURE1);

                glEnable(GL_TEXTURE_2D);

        glBindTexture(GL_TEXTURE_2D, inputTexture2);

                this->shader->enable();

        glBegin(GL_QUADS);

        glColor3d(1.0, 0.0, 0.0);

        glTexCoord2f(0, 0); glVertex3f(-1, -1, 0);

        glTexCoord2f(1, 0); glVertex3f(1, -1, 0);

        glTexCoord2f(1, 1); glVertex3f(1, 1, 0);

        glTexCoord2f(0, 1); glVertex3f(-1, 1, 0);

        glEnd();

        }

        this->shader->disable();

        glPopMatrix();

        glMatrixMode(GL_PROJECTION);

        glPopMatrix();

        glPopAttrib();

        glPopAttrib();

        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);  //should maybe have a stack

        glActiveTexture(GL_TEXTURE1);

        glBindTexture(GL_TEXTURE_2D,0);

        glActiveTexture(GL_TEXTURE0);

        glBindTexture(GL_TEXTURE_2D,0);

        return output_texture;

};

void GPUImageFilter::drawOutputTexture(float x,float y, float w, float h){

        glEnable(GL_TEXTURE_2D);

        glBindTexture(GL_TEXTURE_2D, this->output_texture);

        glPushMatrix();

        glBegin( GL_QUADS );

                glTexCoord2f(0,0);                        glVertex3i(x, y,0);

                glTexCoord2f(1,0);                        glVertex3i(x+w, y,0);

                glTexCoord2f(1,1);                        glVertex3i(x+w, y+h,0);

                glTexCoord2f(0,1);                        glVertex3i(x, y+h,0);

        glEnd();

        glPopMatrix();

}

//destructor

GPUImageFilter::~GPUImageFilter()

{

}