/usr/share/openscenegraph/examples/osgsimpleshaders/osgsimpleshaders.cpp is in openscenegraph-examples 3.2.0~rc1-4.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 | /* OpenSceneGraph example, osgminimalglsl.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/* file: examples/osgminimalglsl.cpp
*
* A minimal demo of the OpenGL Shading Language shaders using core OSG.
*
* blocky shader taken from osgshaders sample (Author: Mike Weiblein)
*/
#include <osgViewer/Viewer>
#include <osg/ShapeDrawable>
#include <osg/Geode>
#include <osg/Vec3>
#include <osg/Program>
#include <osg/Shader>
#include <osg/Uniform>
using namespace osg;
///////////////////////////////////////////////////////////////////////////
// in-line GLSL source code
static const char *blockyVertSource = {
"// blocky.vert - an GLSL vertex shader with animation\n"
"// the App updates uniforms \"slowly\" (eg once per frame) for animation.\n"
"uniform float Sine;\n"
"const vec3 LightPosition = vec3(0.0, 0.0, 4.0);\n"
"const float BlockScale = 0.30;\n"
"// varyings are written by vert shader, interpolated, and read by frag shader.\n"
"varying float LightIntensity;\n"
"varying vec2 BlockPosition;\n"
"void main(void)\n"
"{\n"
" // per-vertex diffuse lighting\n"
" vec4 ecPosition = gl_ModelViewMatrix * gl_Vertex;\n"
" vec3 tnorm = normalize(gl_NormalMatrix * gl_Normal);\n"
" vec3 lightVec = normalize(LightPosition - vec3 (ecPosition));\n"
" LightIntensity = max(dot(lightVec, tnorm), 0.0);\n"
" // blocks will be determined by fragment's position on the XZ plane.\n"
" BlockPosition = gl_Vertex.xz / BlockScale;\n"
" // scale the geometry based on an animation variable.\n"
" vec4 vertex = gl_Vertex;\n"
" vertex.w = 1.0 + 0.4 * (Sine + 1.0);\n"
" gl_Position = gl_ModelViewProjectionMatrix * vertex;\n"
"}\n"
};
static const char *blockyFragSource = {
"// blocky.frag - an GLSL fragment shader with animation\n"
"// the App updates uniforms \"slowly\" (eg once per frame) for animation.\n"
"uniform float Sine;\n"
"const vec3 Color1 = vec3(1.0, 1.0, 1.0);\n"
"const vec3 Color2 = vec3(0.0, 0.0, 0.0);\n"
"// varyings are written by vert shader, interpolated, and read by frag shader.\n"
"varying vec2 BlockPosition;\n"
"varying float LightIntensity;\n"
"void main(void)\n"
"{\n"
" vec3 color;\n"
" float ss, tt, w, h;\n"
" ss = BlockPosition.x;\n"
" tt = BlockPosition.y;\n"
" if (fract(tt * 0.5) > 0.5)\n"
" ss += 0.5;\n"
" ss = fract(ss);\n"
" tt = fract(tt);\n"
" // animate the proportion of block to mortar\n"
" float blockFract = (Sine + 1.1) * 0.4;\n"
" w = step(ss, blockFract);\n"
" h = step(tt, blockFract);\n"
" color = mix(Color2, Color1, w * h) * LightIntensity;\n"
" gl_FragColor = vec4 (color, 1.0);\n"
"}\n"
};
///////////////////////////////////////////////////////////////////////////
// callback for animating various Uniforms (currently only the SIN uniform)
class AnimateCallback: public osg::Uniform::Callback
{
public:
enum Operation { SIN };
AnimateCallback(Operation op) : _operation(op) {}
virtual void operator() ( osg::Uniform* uniform, osg::NodeVisitor* nv )
{
float angle = 2.0 * nv->getFrameStamp()->getSimulationTime();
float sine = sinf( angle ); // -1 -> 1
switch(_operation) {
case SIN : uniform->set( sine ); break;
}
}
private:
Operation _operation;
};
int main(int, char **)
{
// construct the viewer.
osgViewer::Viewer viewer;
// use a geode with a Box ShapeDrawable
osg::Geode* basicModel = new osg::Geode();
basicModel->addDrawable(new osg::ShapeDrawable(new osg::Box(osg::Vec3(0.0f,0.0f,0.0f),1.0f)));
// create the "blocky" shader, a simple animation test
osg::StateSet *ss = basicModel->getOrCreateStateSet();
osg::Program* program = new osg::Program;
program->setName( "blocky" );
program->addShader( new osg::Shader( osg::Shader::VERTEX, blockyVertSource ) );
program->addShader( new osg::Shader( osg::Shader::FRAGMENT, blockyFragSource ) );
ss->setAttributeAndModes(program, osg::StateAttribute::ON);
// attach some animated Uniform variable to the state set
osg::Uniform* SineUniform = new osg::Uniform( "Sine", 0.0f );
ss->addUniform( SineUniform );
SineUniform->setUpdateCallback(new AnimateCallback(AnimateCallback::SIN));
// run the osg::Viewer using our model
viewer.setSceneData( basicModel );
return viewer.run();
}
/*EOF*/
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