!!ARBvp1.0

# Toon Shader by James A. McCombe, Tue Jun 17 2003
#
# Implements a very crude toon shader.  Basically, a simple dot product between a 
# light direction vector and the vertex normal is performed.  The output of this is 
# used to set the texture coordinates to lookup inside a special texture which 
# effectively quantises the light intensity into 3 bands.
#
# Parameters:
#    program.env[0] - Light direction vector

ATTRIB vPosition    = vertex.position;
ATTRIB vNormal      = vertex.normal;

PARAM lightDirection = program.env[0];

TEMP t0, transVertex;

DP4  result.position.x, state.matrix.mvp.row[0], vPosition;
DP4  result.position.y, state.matrix.mvp.row[1], vPosition;
DP4  result.position.z, state.matrix.mvp.row[2], vPosition;
DP4  result.position.w, state.matrix.mvp.row[3], vPosition;

DP3  t0.x, state.matrix.modelview[0].invtrans.row[0], vNormal;
DP3  t0.z, state.matrix.modelview[0].invtrans.row[1], vNormal;
DP3  t0.y, state.matrix.modelview[0].invtrans.row[2], vNormal;

# Dot product of normal and light vector to do tone lookup
DP3  t0, t0, lightDirection;
SWZ  result.texcoord[0], t0, x,1,1,1;

# Write the primary vertex color
MOV  result.color, vertex.color;

END