#version 450
/* Copyright (c) 2020-2021, Holochip
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 the "License";
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

layout(location = 0) in vec3 inPos;
layout(location = 1) in vec3 inNormal;
layout(location = 2) in vec2 inUV;

layout(binding = 0) uniform UBO
{
	mat4 projection;
	mat4 modelview;
	mat4 skybox_modelview;
	int  color_shading_rates;
}
ubo;

layout(location = 0) out vec2 outUV;
layout(location = 1) out vec3 outPos;
layout(location = 2) out vec3 outNormal;
layout(location = 3) out vec3 outViewVec;
layout(location = 4) out vec3 outLightVec;

layout(push_constant) uniform Push_Constants
{
	vec4 offset;
	int  object_type;
}
push_constants;

void main()
{
	switch (push_constants.object_type)
	{
		case 0:        // Skysphere
			outPos      = vec3(mat3(ubo.skybox_modelview) * inPos);
			gl_Position = vec4(ubo.projection * vec4(outPos, 1.0));
			break;
		case 1:        // Object
			vec3 localPos = inPos + push_constants.offset.xyz;
			outPos        = vec3(ubo.modelview * vec4(localPos, 1.0));
			gl_Position   = ubo.projection * ubo.modelview * vec4(localPos, 1.0);
			break;
	}
	outUV         = inUV;
	outNormal     = mat3(ubo.modelview) * inNormal;
	vec3 lightPos = mat3(ubo.modelview) * vec3(0.0, -10.0, -10.0);
	outLightVec   = lightPos.xyz - outPos.xyz;
	outViewVec    = -outPos.xyz;
}