[osg-users] ShaderGen and OpenGL ES2

[yun-ta.tsai]

  Hi all,

I am trying to test OSG (2.9.8) on N900 with OpenGL ES2.
However, ShaderGen.cpp seems to be not fully compatible with OpenGL ES2 
standard.

For instance, gl_LightSource is not defined in ES2 and precision 
attribute (mediump / highp / lowp) has been missing. The later one can 
be easily fixed while the first one using undefined variables is more 
difficult to work around.

Here is the GLSL code generated from ShaderGen.cpp:
Nokia-N900:/home/user/osg-data# /opt/osg/bin/osgviewer cessna.osg
GraphicsWindowX11::init() - eglInitialize() succeded eglMajorVersion=1 
iMinorVersion=4
GraphicsWindowX11::init() - window created =1
State::convertShaderSourceToOsgBuiltIns()
++Before Converted source
varying vec3 normalDir;
varying vec3 lightDir;
varying vec3 viewDir;

void main()
{
   gl_Position = ftransform();
   normalDir = gl_NormalMatrix * gl_Normal;
   vec3 dir = -vec3(gl_ModelViewMatrix * gl_Vertex);
   viewDir = dir;
   vec4 lpos = gl_LightSource[0].position;
   if (lpos.w == 0.0)
     lightDir = lpos.xyz;
   else
     lightDir = lpos.xyz + dir;
}

++++++++
-------- Converted source
uniform mat3 osg_NormalMatrix;
uniform mat4 osg_ModelViewProjectionMatrix;
uniform mat4 osg_ModelViewMatrix;
attribute vec4 osg_Vertex;
attribute vec3 osg_Normal;
varying vec3 normalDir;
varying vec3 lightDir;
varying vec3 viewDir;

void main()
{
   gl_Position = osg_ModelViewProjectionMatrix * osg_Vertex;
   normalDir = osg_NormalMatrix * osg_Normal;
   vec3 dir = -vec3(osg_ModelViewMatrix * osg_Vertex);
   viewDir = dir;
   vec4 lpos = gl_LightSource[0].position;
   if (lpos.w == 0.0)
     lightDir = lpos.xyz;
   else
     lightDir = lpos.xyz + dir;
}

----------------
VERTEX glCompileShader "" FAILED
VERTEX Shader "" infolog:
Compile failed.
ERROR: 0:16: 'gl_LightSource' : undeclared identifer
ERROR: 0:16: 'gl_LightSource' : left of '[' is not of type array, 
matrix, or vector
ERROR: 0:16: 'position' : illegal vector field selection
ERROR: 0:16: 'assign' :  cannot convert from 'float' to '4-component 
vector of float'
ERROR: 4 compilation errors. No code generated.


FRAGMENT glCompileShader "" FAILED
FRAGMENT Shader "" infolog:
Compile failed.
ERROR: 0:1: 'vec3' : No precision defined for this type
ERROR: 0:2: 'vec3' : No precision defined for this type
ERROR: 0:3: 'vec3' : No precision defined for this type
ERROR: 0:7: 'vec4' : No precision defined for this type
ERROR: 0:8: 'vec3' : No precision defined for this type
ERROR: 0:9: 'vec3' : No precision defined for this type
ERROR: 0:10: 'vec3' : No precision defined for this type
ERROR: 0:11: 'vec4' : No precision defined for this type
ERROR: 0:11: 'gl_FrontLightModelProduct' : undeclared identifer
....

Any suggestion?

Thanks.
Best Regards,
Yun-Ta
_______________________________________________
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org