/*

 File: vertexShaderFlat.vs

 Abstract: The vertex shader, which uses instanced attributes, for drawing the gears.

 Version: 1.1

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 */

#version 150

in vec3 attribPosition;

in vec3 attribColor;

in vec3 attribNormal;

in float attribScale; //instanced attribute

in mat4 attribOrientationMatrix; //instanced attribute

uniform mat4 rotationAnimationMatrix;

uniform mat4 cameraMatrix;

uniform mat4 projectionMatrix;

flat out vec3 normal;

out vec3 eyePos;

out vec4 primaryColor;

void main() {

    // compute the transform to eye space

    // note that attribScale and attribOrientationMatrix are advanced once per instance

    mat4 scaleMatrix = mat4(attribScale);

    scaleMatrix[3].w = 1.0;

    mat4 transform = cameraMatrix * attribOrientationMatrix * rotationAnimationMatrix * scaleMatrix;

    // normal

    normal = normalize(transform * vec4(attribNormal, 0.0)).xyz;

    // position

    eyePos = vec3(transform * vec4(attribPosition, 1.0));

    gl_Position = projectionMatrix * vec4(eyePos, 1.0);

    // color

    primaryColor = vec4(attribColor, 1.0);

}