I have been trying to fined examples of the ARB_vertex_program EXT but have had very little success. I have read through the spec.txt and found the example of implement a simple ambient, specular, and diffuse infinite lighting
!!ARBvp1.0
ATTRIB iPos = vertex.position;
ATTRIB iNormal = vertex.normal;
PARAM mvinv[4] = { state.matrix.modelview.invtrans };
PARAM mvp[4] = { state.matrix.mvp };
PARAM lightDir = state.light[0].position;
PARAM halfDir = state.light[0].half;
PARAM specExp = state.material.shininess;
PARAM ambientCol = state.lightprod[0].ambient;
PARAM diffuseCol = state.lightprod[0].diffuse;
PARAM specularCol = state.lightprod[0].specular;
TEMP xfNormal, temp, dots;
OUTPUT oPos = result.position;
OUTPUT oColor = result.color;
# Transform the vertex to clip coordinates.
DP4 oPos.x, mvp[0], iPos;
DP4 oPos.y, mvp[1], iPos;
DP4 oPos.z, mvp[2], iPos;
DP4 oPos.w, mvp[3], iPos;
# Transform the normal to eye coordinates.
DP3 xfNormal.x, mvinv[0], iNormal;
DP3 xfNormal.y, mvinv[1], iNormal;
DP3 xfNormal.z, mvinv[2], iNormal;
# Compute diffuse and specular dot products and use LIT to compute
# lighting coefficients.
DP3 dots.x, xfNormal, lightDir;
DP3 dots.y, xfNormal, halfDir;
MOV dots.w, specExp.x;
LIT dots, dots;
# Accumulate color contributions.
MAD temp, dots.y, diffuseCol, ambientCol;
MAD oColor.xyz, dots.z, specularCol, temp;
MOV oColor.w, diffuseCol.w;
END
I have tried it out but it displays nothing?
I have managed to get the basic example from Nutty site to work so I think all init code is working but I am not sure how to deal with the various attributes/materials?
This is how I draw the triangle:
glEnable(GL_VERTEX_PROGRAM_ARB);
glBindProgramARB(GL_VERTEX_PROGRAM_ARB, my_program);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0f, 0.0f, -140.0f);
glBegin(GL_TRIANGLES);
glNormal3f(0.0f,0.0f,1.0f);
glVertex3f(0.0f, 100.0f, 0.0f);
glNormal3f(0.0f,0.0f,1.0f);
glVertex3f(-100.0f, 0.0f, 0.0f);
glNormal3f(0.0f,0.0f,1.0f);
glVertex3f(100.0f, 0.0f, 0.0f);
glEnd();
glDisable(GL_VERTEX_PROGRAM_ARB);
I think I need to pass in some extra attributes but don’t know witch or how?
Any help/link would be appreciated.
FredFlint.