#include "/Lib/Settings.glsl"
#include "/Lib/Utilities.glsl"
// MinecraftPT — Voxel Profile
// Voxel grid parameters derived from settings.
//
// The shadow framebuffer (shadowcolor0/1) is square, size S x S, and holds:
//   - the VOXEL ATLAS in the bottom-left region: texels [0, W) x [0, H)
//     where W = voxelWidth and H = ceil(N / W), N = Rx*Ry*Rz voxels.
//     Each voxel is one texel; linear packing: n = x + y*Rx + z*Rx*Ry.
//   - the SHADOW MAP in the right square region: texels [W, 2W) x [0, W).
//     The shadow camera NDC is shifted into this region (square -> square,
//     no aspect distortion). Effective shadow resolution = W.

#ifndef VOXEL_PROFILE_GLSL
#define VOXEL_PROFILE_GLSL

// Shadow render distance -> shadow coverage
#if SHADOW_RENDER_DISTANCE == 4
	const float shadowDistance = 64.1;
#elif SHADOW_RENDER_DISTANCE == 6
	const float shadowDistance = 96.1;
#elif SHADOW_RENDER_DISTANCE == 8
	const float shadowDistance = 128.1;
#elif SHADOW_RENDER_DISTANCE == 12
	const float shadowDistance = 192.1;
#elif SHADOW_RENDER_DISTANCE == 16
	const float shadowDistance = 256.1;
#elif SHADOW_RENDER_DISTANCE == 24
	const float shadowDistance = 384.1;
#elif SHADOW_RENDER_DISTANCE == 32
	const float shadowDistance = 512.1;
#elif SHADOW_RENDER_DISTANCE == 48
	const float shadowDistance = 768.1;
#elif SHADOW_RENDER_DISTANCE == 64
	const float shadowDistance = 1024.1;
#elif SHADOW_RENDER_DISTANCE == 96
	const float shadowDistance = 1536.1;
#elif SHADOW_RENDER_DISTANCE == 128
	const float shadowDistance = 2048.1;
#else
	const float shadowDistance = 256.1;
#endif

// Voxel grid resolution and coverage (blocks)
#if   PT_VOXEL_RESOLUTION == 4004
	const ivec3 voxelResolutionInt = ivec3(128);
	const float voxelDistance = 64.0;
	const int voxelWidth = 2048;
#elif PT_VOXEL_RESOLUTION == 6004
	const ivec3 voxelResolutionInt = ivec3(192, 128, 192);
	const float voxelDistance = 96.0;
	const int voxelWidth = 2048;
#elif PT_VOXEL_RESOLUTION == 8004
	const ivec3 voxelResolutionInt = ivec3(256, 128, 256);
	const float voxelDistance = 128.0;
	const int voxelWidth = 2048;
#elif PT_VOXEL_RESOLUTION == 8006
	const ivec3 voxelResolutionInt = ivec3(256, 192, 256);
	const float voxelDistance = 128.0;
	const int voxelWidth = 4096;
#elif PT_VOXEL_RESOLUTION == 8008
	const ivec3 voxelResolutionInt = ivec3(256);
	const float voxelDistance = 128.0;
	const int voxelWidth = 4096;
#elif PT_VOXEL_RESOLUTION == 12004
	const ivec3 voxelResolutionInt = ivec3(384, 128, 384);
	const float voxelDistance = 192.0;
	const int voxelWidth = 4096;
#elif PT_VOXEL_RESOLUTION == 12006
	const ivec3 voxelResolutionInt = ivec3(384, 192, 384);
	const float voxelDistance = 192.0;
	const int voxelWidth = 4096;
#elif PT_VOXEL_RESOLUTION == 12008
	const ivec3 voxelResolutionInt = ivec3(384, 256, 384);
	const float voxelDistance = 192.0;
	const int voxelWidth = 6144;
#elif PT_VOXEL_RESOLUTION == 16004
	const ivec3 voxelResolutionInt = ivec3(512, 128, 512);
	const float voxelDistance = 256.0;
	const int voxelWidth = 6144;
#elif PT_VOXEL_RESOLUTION == 16008
	const ivec3 voxelResolutionInt = ivec3(512, 256, 512);
	const float voxelDistance = 256.0;
	const int voxelWidth = 6144;
#elif PT_VOXEL_RESOLUTION == 16016
	const ivec3 voxelResolutionInt = ivec3(512);
	const float voxelDistance = 256.0;
	const int voxelWidth = 8192;
#else
	const ivec3 voxelResolutionInt = ivec3(256, 192, 256);
	const float voxelDistance = 128.0;
	const int voxelWidth = 4096;
#endif

const vec3 voxelResolution = vec3(voxelResolutionInt);

// Irradiance cache resolution (clamped to voxel grid)
const int ircResolution = min(PT_IRC_RESOLUTION, voxelResolutionInt.x);

// Shadow framebuffer size (square)
const int shadowMapResolution = voxelWidth * 2;
const float shadowSize = float(shadowMapResolution);
const float shadowPixelSize = 1.0 / shadowSize;
const float shadowRatio = 0.5; // W / S

// Map 3D voxel coordinate to 2D atlas texel (linear packing)
vec2 VoxelTexel_From_VoxelCoord(vec3 voxelCoord){
	float n = voxelCoord.x + voxelCoord.y * voxelResolution.x + voxelCoord.z * voxelResolution.x * voxelResolution.y;
	return vec2(mod(n, float(voxelWidth)), floor(n / float(voxelWidth)));
}

// Shift shadow map NDC into the right square region [W, 2W] x [0, W]
void ShiftShadowNdcPos(inout vec2 coord){
	coord = coord * shadowRatio + vec2(1.0 - shadowRatio, shadowRatio - 1.0);
}

// Shift shadow map screen uv into the right square region
void ShiftShadowScreenPos(inout vec2 coord){
	coord = coord * shadowRatio + vec2(1.0 - shadowRatio, 0.0);
}

// Shift back from shadow region uv to standard shadow uv
vec2 UnshiftShadowScreenPos(vec2 coord){
	return (coord - vec2(1.0 - shadowRatio, 0.0)) / shadowRatio;
}

// Block ID encoding (16-bit range)
// Full block: voxelID + 1000
// Cutout shape: 1000 - voxelID
// Empty markers: 0.91 (8^3), 0.71 (4^3), 0.61 (2^3)
float EncodeVoxelID(float voxelID){
	return saturate((voxelID + 1000.0) / 65535.0);
}

float DecodeVoxelID(float encoded){
	return abs(floor(encoded * 65535.0 - 999.9));
}

#endif