#version 120

attribute vec3 a_position;
attribute vec3 a_normal;
attribute vec2 a_texcoord;
attribute vec4 a_boneIds;
attribute vec4 a_weights;

varying vec3 v_position;
varying vec3 v_normal;
varying vec2 v_texcoord;
varying vec3 v_finalColor;

uniform mat4 u_modelMatrix;
uniform mat4 u_viewMatrix;
uniform mat4 u_projectionMatrix;
uniform mat4 u_modelViewProjection;
uniform mat4 u_boneMatrices[128];

void main() {
	// calculate bone transform
	mat4 skinMatrix = a_weights.x * u_boneMatrices[ int( a_boneIds.x ) ]
		+ a_weights.y * u_boneMatrices[ int( a_boneIds.y ) ]
		+ a_weights.z * u_boneMatrices[ int( a_boneIds.z ) ]
		+ a_weights.w * u_boneMatrices[ int( a_boneIds.w ) ];

	// Position
	v_position = vec3( skinMatrix * vec4( a_position, 1.0 ) );
	v_position = vec3( u_modelMatrix * vec4( v_position, 1.0 ) );
	
	v_normal = vec3( mat3(u_modelMatrix) * a_normal );
	v_texcoord = a_texcoord;
	gl_Position = u_projectionMatrix * u_viewMatrix * vec4( v_position, 1.0 );
}