Hi Liu,
consider this simple pseudo code example ( just fix
createTexturedQuadGeometry in code below so that it has #if
defined(OSG_GLES1_AVAILABLE) || defined(OSG_GLES2_AVAILABLE) line instead of
#if defined(OSG_GLES1_AVAILABLE) || !defined(OSG_GLES2_AVAILABLE) ) )
have u_Texture sampler in your shader
uniform sampler2D u_Texture;
then create geode
osg::Geode* geode = new osg::Geode();
osg::Program* program = new osg::Program();
osg::Shader* vert = new osg::Shader(osg::Shader::VERTEX,
gVertexShader);
osg::Shader* frag = new osg::Shader(osg::Shader::FRAGMENT,
gFragmentShader );
program->addShader(vert);
program->addShader(frag);
geode->addDrawable(makePlain ());
osg::StateSet* pStateSet = geode->getOrCreateStateSet();
osg::Image* pImage = new osg::Image;
load image here, now
osg::Texture2D* pTex = new osg::Texture2D();
pTex->setFilter( pTex->MIN_FILTER,pTex->LINEAR);
pTex->setFilter( pTex->MAG_FILTER,pTex->LINEAR);
pTex->setImage(0, pImage);
pStateSet->setTextureAttribute( 0, pTex, osg::StateAttribute::ON );
pStateSet->addUniform(new osg::Uniform("u_Texture", 0));
pStateSet->setAttribute(program);
makePlain could be as following:
osg::Geometry*
makePlain()
{
osg::ref_ptr<osg::Geometry> geom= osg::createTexturedQuadGeometry(
osg::Vec3(-0.5f, 0.0f,-0.5f),
osg::Vec3(1.0f,0.0f,0.0f),
osg::Vec3(0.0f,0.0f,1.0f) );
if( geom == NULL )
geom = new osg::Geometry;
geom->setUseVertexBufferObjects(true);
return( geom.release() );
}
this simple example should work, then you should move further.
Regards
Sergey
On Fri, Nov 7, 2014 at 3:56 PM, Liu Xiao <[email protected]> wrote:
> Thanks so much for your quick reply , it really helps.
>
> Also this post gives me a good example of shader:
> http://forum.openscenegraph.org/viewtopic.php?t=6482
>
> But still I have problem on drawing the texture.
>
>
> Sergey Kurdakov wrote:
> > Hi Liu,
> >
> >
> > use setUseVertexAttributeAliasing as Robert recently explained for
> similar question
> >
> > ===
> > The aliasing of gl_* uniforms to osg_* equivialants is not done by
> default. You can switch it one yourself if required though via osg::State,
> from the osgsimplegl3 example:
> >
> > // for non GL3/GL4 and non GLES2 platforms we need enable the osg_
> uniforms that the shaders will use,
> > // you don't need thse two lines on GL3/GL4 and GLES2 specific
> builds as these will be enable by default.
> > gc->getState()->setUseModelViewAndProjectionUniforms(true);
> > gc->getState()->setUseVertexAttributeAliasing(true);
> >
> >
> > In your own shaders if you are building against GL1/2 (default build of
> OSG) then you can simply use the gl_* parameters.
> >
> > Also have a look at the shaders in OpenSceneGraph-Data and the
> osgshaders example.
> > ===
> >
> >
> >
> >
> > Regards
> > Sergey
> >
> > On Fri, Nov 7, 2014 at 12:14 PM, Liu Xiao < ()> wrote:
> >
> > > Hi,
> > >
> > > When I trying to use the osg 3.2.1 (with OSG_GLES2_AVAILABLE:BOOL=ON )
> example_osgViewerIPhone, I got the following errors:
> > >
> > >
> > > Code:
> > > VERTEX glCompileShader "" FAILED
> > > VERTEX Shader "" infolog:
> > > ERROR: 0:6: Use of undeclared identifier 'gl_Vertex'
> > > ERROR: 0:7: Use of undeclared identifier 'gl_FrontColor'
> > >
> > > FRAGMENT glCompileShader "" FAILED
> > > FRAGMENT Shader "" infolog:
> > > ERROR: 0:4: 'vec4' : declaration must include a precision qualifier
> for type
> > > ERROR: 0:5: Use of undeclared identifier 'base'
> > > ERROR: 0:6: Use of undeclared identifier 'color'
> > > ERROR: 0:6: Use of undeclared identifier 'gl_Color'
> > > ERROR: 0:7: Use of undeclared identifier 'color'
> > >
> > > glLinkProgram "" FAILED
> > > Program "" infolog:
> > > ERROR: One or more attached shaders not successfully compiled
> > >
> > >
> > >
> > > My Config file is as follows:
> > >
> > >
> > > Code:
> > > #ifndef OSG_CONFIG
> > > #define OSG_CONFIG 1
> > >
> > > /* #undef OSG_NOTIFY_DISABLED */
> > > /* #undef OSG_USE_FLOAT_MATRIX */
> > > /* #undef OSG_USE_FLOAT_PLANE */
> > > #define OSG_USE_FLOAT_BOUNDINGSPHERE
> > > #define OSG_USE_FLOAT_BOUNDINGBOX
> > > #define OSG_USE_REF_PTR_IMPLICIT_OUTPUT_CONVERSION
> > > /* #undef OSG_USE_UTF8_FILENAME */
> > > #define OSG_DISABLE_MSVC_WARNINGS
> > >
> > > /* #undef OSG_GL1_AVAILABLE */
> > > /* #undef OSG_GL2_AVAILABLE */
> > > /* #undef OSG_GL3_AVAILABLE */
> > > /* #undef OSG_GLES1_AVAILABLE */
> > > #define OSG_GLES2_AVAILABLE
> > > /* #undef OSG_GL_LIBRARY_STATIC */
> > > /* #undef OSG_GL_DISPLAYLISTS_AVAILABLE */
> > > /* #undef OSG_GL_MATRICES_AVAILABLE */
> > > /* #undef OSG_GL_VERTEX_FUNCS_AVAILABLE */
> > > /* #undef OSG_GL_VERTEX_ARRAY_FUNCS_AVAILABLE */
> > > /* #undef OSG_GL_FIXED_FUNCTION_AVAILABLE */
> > >
> > > #endif
> > >
> > >
> > >
> > >
> > > Can anyone help with this? Or is there any examples of osg ios can I
> learn?
> > >
> > > Thank you!
> > >
> > > Cheers,
> > > Liu
> > >
> > > ------------------
> > > Read this topic online here:
> > > http://forum.openscenegraph.org/viewtopic.php?p=61538#61538 (
> http://forum.openscenegraph.org/viewtopic.php?p=61538#61538)
> > >
> > >
> > >
> > >
> > >
> > > _______________________________________________
> > > osg-users mailing list
> > > ()
> > >
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
> (http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
> )
> > >
> >
> >
> > ------------------
> > Post generated by Mail2Forum
>
>
> ------------------
> Read this topic online here:
> http://forum.openscenegraph.org/viewtopic.php?p=61545#61545
>
>
>
>
>
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