#version 450 core
layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aNormal;
layout (location = 2) in vec2 aTexCoords;
layout (location = 3) in ivec4 boneIds; 
layout (location = 4) in vec4 weights;
 
out vec2 TexCoords;
out vec3 WorldPos;
out vec3 Normal;

uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;

const int MAX_BONES = 100;
const int MAX_BONE_INFLUENCE = 4;
layout (std140, binding = 1) uniform FinalBonesMatrices
{
    mat4 finalBonesMatrices[MAX_BONES];
};

void main()
{
	vec4 totalPosition = vec4(0.0f);
	vec3 totalNormal = vec3(0);
	int boneCount = 0;
	for(int i = 0 ; i < MAX_BONE_INFLUENCE ; i++)
	{
		if(boneIds[i] == -1) 
			continue;
		if(boneIds[i] >= MAX_BONES) 
		{
			totalPosition = vec4(aPos,1.0f);
			break;
		}
		boneCount++;
		vec4 localPosition = finalBonesMatrices[boneIds[i]] * vec4(aPos,1.0f);
		totalPosition += localPosition * weights[i];
		vec3 localNormal = mat3(finalBonesMatrices[boneIds[i]]) * aNormal;
		totalNormal += localNormal * weights[i];
	}

	if(boneCount == 0)
	{
		totalPosition = vec4(aPos, 1);
		totalNormal = vec3(aNormal);
	}

	TexCoords = aTexCoords;
	WorldPos = vec3(model * totalPosition);
	Normal = mat3(model) * totalNormal;   

	gl_Position =  projection * view * vec4(WorldPos, 1.0);
}