/* Copyright (c) 2024, Sascha Willems
 *
 * 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.
 */

 struct VSInput
{
[[vk::location(0)]] float3 Position : POSITION0;
[[vk::location(1)]] float3 Normal : NORMAL0;
};

[[vk::binding(0, 0)]]
RaytracingAccelerationStructure topLevelAS : register(t0);

struct GlobalUniform
{
	float4x4 view;
	float4x4 proj;
	float4 camera_position;
	float4 light_position;
};
[[vk::binding(1, 0)]]
ConstantBuffer<GlobalUniform> global_uniform : register(b1);

struct VSOutput
{
    float4 Pos : SV_POSITION;
    [[vk::location(0)]] float4 O_Pos : TEXCOORD0;
    [[vk::location(1)]] float3 O_Normal : NORMAL0;
	[[vk::location(2)]] float4 Scene_pos : TEXCOORD1;	// scene with respect to BVH coordinates
};

VSOutput main(VSInput input)
{
    VSOutput output = (VSOutput) 0;

	// We want to be able to perform ray tracing, so don't apply any matrix to scene_pos
	output.Scene_pos = float4(input.Position, 1.0);
    
	output.O_Pos = mul(global_uniform.view, float4(input.Position, 1.0));

	output.O_Normal = input.Normal;

	output.Pos = mul(global_uniform.proj, mul(global_uniform.view, float4(input.Position, 1.0)));
    
	return output;
}