root/OpenSceneGraph/trunk/examples/osgmultiplerendertargets/osgmultiplerendertargets.cpp @ 13719

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1/* OpenSceneGraph example, osgmultiplerendertargets.
2*
3*  Permission is hereby granted, free of charge, to any person obtaining a copy
4*  of this software and associated documentation files (the "Software"), to deal
5*  in the Software without restriction, including without limitation the rights
6*  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
7*  copies of the Software, and to permit persons to whom the Software is
8*  furnished to do so, subject to the following conditions:
9*
10*  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
11*  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
12*  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
13*  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
14*  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
15*  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
16*  THE SOFTWARE.
17*/
18
19#include <osg/GLExtensions>
20#include <osg/Node>
21#include <osg/Geometry>
22#include <osg/Notify>
23#include <osg/MatrixTransform>
24#include <osg/Texture2D>
25#include <osg/TextureRectangle>
26#include <osg/ColorMask>
27#include <osg/Material>
28
29#include <osgGA/TrackballManipulator>
30#include <osgGA/FlightManipulator>
31#include <osgGA/DriveManipulator>
32
33#include <osgViewer/Viewer>
34
35#include <iostream>
36#include <stdio.h>
37
38//
39// Below is relatively straight forward example of using the OpenGL multiple render targets (MRT) extension
40// to FrameBufferObjects/GLSL shaders.
41//
42// Another, more sophisticated MRT example can be found in the osgstereomatch example.
43//
44
45
46// The callback modifies an input image.
47struct MyCameraPostDrawCallback : public osg::Camera::DrawCallback
48{
49    MyCameraPostDrawCallback(osg::Image* image):
50        _image(image)
51    {
52    }
53
54    virtual void operator () (const osg::Camera& /*camera*/) const
55    {
56        if (_image && _image->getPixelFormat()==GL_RGBA && _image->getDataType()==GL_UNSIGNED_BYTE)
57        {
58            // we'll pick out the center 1/2 of the whole image,
59            int column_start = _image->s()/4;
60            int column_end = 3*column_start;
61
62            int row_start = _image->t()/4;
63            int row_end = 3*row_start;
64
65            // and then halve their contribution
66            for(int r=row_start; r<row_end; ++r)
67            {
68                unsigned char* data = _image->data(column_start, r);
69                for(int c=column_start; c<column_end; ++c)
70                {
71                    (*data) = (*data)/2; ++data;
72                    (*data) = (*data)/2; ++data;
73                    (*data) = (*data)/2; ++data;
74                    (*data) = 255; ++data;
75                }
76            }
77
78            _image->dirty();
79        }
80        else if (_image && _image->getPixelFormat()==GL_RGBA && _image->getDataType()==GL_FLOAT)
81        {
82            // we'll pick out the center 1/2 of the whole image,
83            int column_start = _image->s()/4;
84            int column_end = 3*column_start;
85
86            int row_start = _image->t()/4;
87            int row_end = 3*row_start;
88
89            // and then halve their contribution
90            for(int r=row_start; r<row_end; ++r)
91            {
92                float* data = (float*)_image->data(column_start, r);
93                for(int c=column_start; c<column_end; ++c)
94                {
95                    (*data) = (*data)/2.0; ++data;
96                    (*data) = (*data)/2.0; ++data;
97                    (*data) = (*data)/2.0; ++data;
98                    (*data) = 1.0f; ++data;
99                }
100            }
101
102            _image->dirty();
103
104            //print out the first three values
105            float* data = (float*)_image->data(0, 0);
106            fprintf(stderr,"Float pixel data: r %e g %e b %e\n", data[0], data[1], data[2]);
107        }
108    }
109
110    osg::Image* _image;
111};
112
113#define NUM_TEXTURES 4
114
115// The quad geometry is used by the render to texture camera to generate multiple textures.
116osg::Group* createRTTQuad(unsigned int tex_width, unsigned int tex_height, bool useHDR)
117{
118    osg::Group *top_group = new osg::Group;
119
120    osg::ref_ptr<osg::Geode> quad_geode = new osg::Geode;
121
122    osg::ref_ptr<osg::Vec3Array> quad_coords = new osg::Vec3Array; // vertex coords
123    // counter-clockwise
124    quad_coords->push_back(osg::Vec3d(0, 0, -1));
125    quad_coords->push_back(osg::Vec3d(1, 0, -1));
126    quad_coords->push_back(osg::Vec3d(1, 1, -1));
127    quad_coords->push_back(osg::Vec3d(0, 1, -1));
128
129    osg::ref_ptr<osg::Vec2Array> quad_tcoords = new osg::Vec2Array; // texture coords
130    quad_tcoords->push_back(osg::Vec2(0, 0));
131    quad_tcoords->push_back(osg::Vec2(tex_width, 0));
132    quad_tcoords->push_back(osg::Vec2(tex_width, tex_height));
133    quad_tcoords->push_back(osg::Vec2(0, tex_height));
134
135    osg::ref_ptr<osg::Geometry> quad_geom = new osg::Geometry;
136    osg::ref_ptr<osg::DrawArrays> quad_da = new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,4);
137
138    osg::ref_ptr<osg::Vec4Array> quad_colors = new osg::Vec4Array;
139    quad_colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
140
141    quad_geom->setVertexArray(quad_coords.get());
142    quad_geom->setTexCoordArray(0, quad_tcoords.get());
143    quad_geom->addPrimitiveSet(quad_da.get());
144    quad_geom->setColorArray(quad_colors.get(), osg::Array::BIND_OVERALL);
145
146    osg::StateSet *stateset = quad_geom->getOrCreateStateSet();
147    stateset->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
148
149    stateset->addUniform(new osg::Uniform("width", (int)tex_width));
150
151    // Attach shader, glFragData is used to create data for multiple render targets
152
153    if (useHDR) {
154        static const char *shaderSource = {
155            "uniform int width;"
156            "void main(void)\n"
157            "{\n"
158            "    gl_FragData[0] = vec4(-1e-12,0,0,1);\n"
159            "    gl_FragData[1] = vec4(0,1e-12,0,1);\n"
160            "    gl_FragData[2] = vec4(0,0,1e-12,1);\n"
161            "    gl_FragData[3] = vec4(0,0,1e-12,1);\n"
162            "}\n"
163        };
164
165        osg::ref_ptr<osg::Shader> fshader = new osg::Shader( osg::Shader::FRAGMENT , shaderSource);
166        osg::ref_ptr<osg::Program> program = new osg::Program;
167        program->addShader(fshader.get());
168        stateset->setAttributeAndModes(program.get(), osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE );
169    } else {
170        static const char *shaderSource = {
171            "uniform int width;"
172            "void main(void)\n"
173            "{\n"
174            "    gl_FragData[0] = vec4(1,0,0,1);\n"
175            "    gl_FragData[1] = vec4(0,1,0,1);\n"
176            "    gl_FragData[2] = vec4(0,0,1,1);\n"
177            "    gl_FragData[3] = vec4(0,0,1,1);\n"
178            "}\n"
179        };
180
181        osg::ref_ptr<osg::Shader> fshader = new osg::Shader( osg::Shader::FRAGMENT , shaderSource);
182        osg::ref_ptr<osg::Program> program = new osg::Program;
183        program->addShader(fshader.get());
184        stateset->setAttributeAndModes(program.get(), osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE );
185    }
186
187    quad_geode->addDrawable(quad_geom.get());
188
189    top_group->addChild(quad_geode.get());
190
191    return top_group;
192}
193
194// Here a scene consisting of a single quad is created. This scene is viewed by the screen camera.
195// The quad is textured using a shader and the multiple textures generated in the RTT stage.
196osg::Node* createScene(osg::Node* cam_subgraph, unsigned int tex_width, unsigned int tex_height, bool useHDR, bool useImage, bool useMultiSample)
197{
198    if (!cam_subgraph) return 0;
199
200    // create a group to contain the quad and the pre render camera.
201    osg::Group* parent = new osg::Group;
202
203    // textures to render to and to use for texturing of the final quad
204    osg::TextureRectangle* textureRect[NUM_TEXTURES] = {0,0,0,0};
205
206    for (int i=0;i<NUM_TEXTURES;i++) {
207        textureRect[i] = new osg::TextureRectangle;
208        textureRect[i]->setTextureSize(tex_width, tex_height);
209        textureRect[i]->setInternalFormat(GL_RGBA);
210        textureRect[i]->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
211        textureRect[i]->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
212
213        if (useHDR)
214        {
215            // Default HDR format
216            textureRect[i]->setInternalFormat(GL_RGBA32F_ARB);
217
218            // GL_FLOAT_RGBA32_NV might be supported on pre 8-series GPUs
219            //textureRect[i]->setInternalFormat(GL_FLOAT_RGBA32_NV);
220
221            // GL_RGBA16F_ARB can be used with this example,
222            // but modify e-12 and e12 in the shaders accordingly
223            //textureRect[i]->setInternalFormat(GL_RGBA16F_ARB);
224
225            textureRect[i]->setSourceFormat(GL_RGBA);
226            textureRect[i]->setSourceType(GL_FLOAT);
227        }
228    }
229
230    // first create the geometry of the quad
231    {
232        osg::Geometry* polyGeom = new osg::Geometry();
233
234        polyGeom->setSupportsDisplayList(false);
235
236        osg::Vec3Array* vertices = new osg::Vec3Array;
237        osg::Vec2Array* texcoords = new osg::Vec2Array;
238
239        vertices->push_back(osg::Vec3d(0,0,0));
240        texcoords->push_back(osg::Vec2(0,0));
241
242        vertices->push_back(osg::Vec3d(1,0,0));
243        texcoords->push_back(osg::Vec2(tex_width,0));
244
245        vertices->push_back(osg::Vec3d(1,0,1));
246        texcoords->push_back(osg::Vec2(tex_width,tex_height));
247
248        vertices->push_back(osg::Vec3d(0,0,1));
249        texcoords->push_back(osg::Vec2(0,tex_height));
250
251        polyGeom->setVertexArray(vertices);
252        polyGeom->setTexCoordArray(0,texcoords);
253
254        osg::Vec4Array* colors = new osg::Vec4Array;
255        colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
256        polyGeom->setColorArray(colors, osg::Array::BIND_OVERALL);
257
258        polyGeom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,vertices->size()));
259
260        // now we need to add the textures (generated by RTT) to the Drawable.
261        osg::StateSet* stateset = new osg::StateSet;
262        for (int i=0;i<NUM_TEXTURES;i++){
263            stateset->setTextureAttributeAndModes(i, textureRect[i], osg::StateAttribute::ON);
264        }
265
266        polyGeom->setStateSet(stateset);
267
268        // Attach a shader to the final quad to combine the input textures.
269        if (useHDR) {
270            static const char *shaderSource = {
271                "uniform sampler2DRect textureID0;\n"
272                "uniform sampler2DRect textureID1;\n"
273                "uniform sampler2DRect textureID2;\n"
274                "uniform sampler2DRect textureID3;\n"
275                "uniform float width;\n"
276                "uniform float height; \n"
277                "void main(void)\n"
278                "{\n"
279                "    gl_FragData[0] = \n"
280                "     vec4(  -1e12 * texture2DRect( textureID0, gl_TexCoord[0].st ).rgb, 1) + \n"
281                "     vec4(   1e12 * texture2DRect( textureID1, gl_TexCoord[0].st ).rgb, 1) + \n"
282                "     vec4(   1e12 * texture2DRect( textureID2, gl_TexCoord[0].st ).rgb, 1) + \n"
283                "     vec4(-0.5e12 * texture2DRect( textureID3, gl_TexCoord[0].st ).rgb, 1);  \n"
284                "}\n"
285            };
286            osg::ref_ptr<osg::Shader> fshader = new osg::Shader( osg::Shader::FRAGMENT , shaderSource);
287            osg::ref_ptr<osg::Program> program = new osg::Program;
288            program->addShader( fshader.get());
289            stateset->setAttributeAndModes( program.get(), osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE );
290        } else {
291            static const char *shaderSource = {
292                "uniform sampler2DRect textureID0;\n"
293                "uniform sampler2DRect textureID1;\n"
294                "uniform sampler2DRect textureID2;\n"
295                "uniform sampler2DRect textureID3;\n"
296                "void main(void)\n"
297                "{\n"
298                "    gl_FragData[0] = \n"
299                "          vec4(texture2DRect( textureID0, gl_TexCoord[0].st ).rgb, 1) + \n"
300                "          vec4(texture2DRect( textureID1, gl_TexCoord[0].st ).rgb, 1) + \n"
301                "          vec4(texture2DRect( textureID2, gl_TexCoord[0].st ).rgb, 1) + \n"
302                "     -0.5*vec4(texture2DRect( textureID3, gl_TexCoord[0].st ).rgb, 1);  \n"
303                "}\n"
304            };
305            osg::ref_ptr<osg::Shader> fshader = new osg::Shader( osg::Shader::FRAGMENT , shaderSource);
306            osg::ref_ptr<osg::Program> program = new osg::Program;
307            program->addShader( fshader.get());
308            stateset->setAttributeAndModes( program.get(), osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE );
309
310        }
311
312        stateset->addUniform(new osg::Uniform("textureID0", 0));
313        stateset->addUniform(new osg::Uniform("textureID1", 1));
314        stateset->addUniform(new osg::Uniform("textureID2", 2));
315        stateset->addUniform(new osg::Uniform("textureID3", 3));
316
317        //stateset->setDataVariance(osg::Object::DYNAMIC);
318
319        osg::Geode* geode = new osg::Geode();
320        geode->addDrawable(polyGeom);
321
322        parent->addChild(geode);
323    }
324
325    // now create the camera to do the multiple render to texture
326    {
327        osg::Camera* camera = new osg::Camera;
328
329        // set up the background color and clear mask.
330        camera->setClearColor(osg::Vec4(0.1f,0.1f,0.3f,1.0f));
331        camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
332
333        // the camera is going to look at our input quad
334        camera->setProjectionMatrix(osg::Matrix::ortho2D(0,1,0,1));
335        camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
336        camera->setViewMatrix(osg::Matrix::identity());
337
338        // set viewport
339        camera->setViewport(0, 0, tex_width, tex_height);
340
341        // set the camera to render before the main camera.
342        camera->setRenderOrder(osg::Camera::PRE_RENDER);
343
344        // tell the camera to use OpenGL frame buffer objects
345        camera->setRenderTargetImplementation(osg::Camera::FRAME_BUFFER_OBJECT);
346
347        // attach the textures to use
348        for (int i=0; i<NUM_TEXTURES; i++) {
349            if (useMultiSample)
350                camera->attach(osg::Camera::BufferComponent(osg::Camera::COLOR_BUFFER0+i), textureRect[i], 0, 0, false, 4, 4);
351            else
352                camera->attach(osg::Camera::BufferComponent(osg::Camera::COLOR_BUFFER0+i), textureRect[i]);
353
354
355        }
356
357        // we can also read back any of the targets as an image, modify this image and push it back
358        if (useImage) {
359            // which texture to get the image from
360            const int tex_to_get = 0;
361
362            osg::Image* image = new osg::Image;
363            if (useHDR) {
364                image->allocateImage(tex_width, tex_height, 1, GL_RGBA, GL_FLOAT);
365            } else {
366                image->allocateImage(tex_width, tex_height, 1, GL_RGBA, GL_UNSIGNED_BYTE);
367            }
368
369            // attach the image so its copied on each frame.
370            camera->attach(osg::Camera::BufferComponent(osg::Camera::COLOR_BUFFER0 + tex_to_get), image);
371
372            camera->setPostDrawCallback(new MyCameraPostDrawCallback(image));
373
374            // push back the image to the texture
375            textureRect[tex_to_get]->setImage(0, image);
376        }
377
378        // add the subgraph to render
379        camera->addChild(cam_subgraph);
380
381        parent->addChild(camera);
382    }
383
384    return parent;
385}
386
387int main( int argc, char **argv )
388{
389    // use an ArgumentParser object to manage the program arguments.
390    osg::ArgumentParser arguments(&argc,argv);
391
392    // set up the usage document, in case we need to print out how to use this program.
393    arguments.getApplicationUsage()->setDescription(arguments.getApplicationName() + " demonstrates the use of multiple render targets (MRT) with frame buffer objects (FBOs). A render to texture (RTT) camera is used to render to four textures using a single shader. The four textures are then combined to texture the viewed geometry.");
394    arguments.getApplicationUsage()->setCommandLineUsage(arguments.getApplicationName()+" [options] ...");
395    arguments.getApplicationUsage()->addCommandLineOption("-h or --help","Display this information.");
396    arguments.getApplicationUsage()->addCommandLineOption("--width","Set the width of the render to texture.");
397    arguments.getApplicationUsage()->addCommandLineOption("--height","Set the height of the render to texture.");
398    arguments.getApplicationUsage()->addCommandLineOption("--image","Render one of the targets to an image, then apply a post draw callback to modify it and use this image to update the final texture. Print some texture values when using HDR.");
399    arguments.getApplicationUsage()->addCommandLineOption("--hdr","Use high dynamic range (HDR). Create floating point textures to render to.");
400
401    // construct the viewer.
402    osgViewer::Viewer viewer(arguments);
403
404    // if user request help write it out to cout.
405    if (arguments.read("-h") || arguments.read("--help"))
406    {
407        arguments.getApplicationUsage()->write(std::cout);
408        return 1;
409    }
410
411    unsigned tex_width = 512;
412    unsigned tex_height = 512;
413    while (arguments.read("--width", tex_width)) {}
414    while (arguments.read("--height", tex_height)) {}
415
416    bool useHDR = false;
417    while (arguments.read("--hdr")) { useHDR = true; }
418
419    bool useImage = false;
420    while (arguments.read("--image")) { useImage = true; }
421
422    bool useMultiSample = false;
423    while (arguments.read("--ms")) { useMultiSample = true; }
424
425    osg::Group* subGraph = createRTTQuad(tex_width, tex_height, useHDR);
426
427    osg::Group* rootNode = new osg::Group();
428    rootNode->addChild(createScene(subGraph, tex_width, tex_height, useHDR, useImage, useMultiSample));
429
430    // add model to the viewer.
431    viewer.setSceneData( rootNode );
432
433    return viewer.run();
434}
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