// MinecraftPT — Terrain Fragment Shader
// Writes the solid and translucent GBuffer

#include "/Lib/Settings.glsl"
#include "/Lib/Utilities.glsl"

in vec2 texcoord;
in vec3 worldPos;
in vec3 worldNormal;
in vec3 vertexNormal;
in vec4 color;
in vec2 lightmap;
flat in int blockId;
flat in float blockLightLevel;

layout(location = 0) out vec4 colortex0Out; // albedo + emissive
layout(location = 1) out vec4 colortex1Out; // normals
layout(location = 2) out vec4 colortex2Out; // spec + matID
layout(location = 3) out vec4 colortex3Out; // lightmap
layout(location = 4) out vec4 colortex4Out; // translucent albedo + alpha
layout(location = 5) out vec4 colortex5Out; // translucent normal + matID

// Material IDs from block.properties
#define BLOCK_LEAVES       1
#define BLOCK_TRANSLUCENT  2
#define BLOCK_WATER        3
#define BLOCK_CROSS        4
#define BLOCK_TORCH        5
#define BLOCK_LANTERN      6
#define BLOCK_FIRE         7
#define BLOCK_CAMPFIRE     8
#define BLOCK_LAVA         9
#define BLOCK_GLASS_PANE   10
#define BLOCK_IRON_BARS    11
#define BLOCK_STAIRS       12
#define BLOCK_SLAB         13
#define BLOCK_WALL         14
#define BLOCK_FENCE        15
#define BLOCK_FENCE_GATE   16
#define BLOCK_DOOR         17
#define BLOCK_RAIL         18
#define BLOCK_REDSTONE     19
#define BLOCK_ENDROD       20
#define BLOCK_CHAIN        21
#define BLOCK_AMETHYST     22
#define BLOCK_CANDLE       23
#define BLOCK_GLOWSTONE    24
#define BLOCK_LIGHT        25
#define BLOCK_PORTAL       26
#define BLOCK_LADDER       27
#define BLOCK_SUGARCANE    28
#define BLOCK_BAMBOO       29
#define BLOCK_CACTUS       30
#define BLOCK_CHORUS       31
#define BLOCK_CORAL        32
#define BLOCK_DRIPSTONE    33
#define BLOCK_CONDUIT      34
#define BLOCK_LIGHTNING_ROD 35
#define BLOCK_POT          36
#define BLOCK_SNOW_LAYERS  37
#define BLOCK_COBWEB       80

void main(){
	vec4 albedo = texture(tex, texcoord) * color;

	// Cutout (alpha test)
	if (albedo.a < 0.004) discard;

	// Material ID determination
	float matID = 0.0;   // MATID_DEFAULT
	#ifdef IS_HAND
		matID = 5.0;    // MATID_HAND
	#endif
	bool isTranslucent = false;

	if (blockId == BLOCK_LEAVES){
		matID = 3.0;    // MATID_LEAVES
	}else if (blockId == BLOCK_TRANSLUCENT){
		matID = 2.0;    // MATID_STAINEDGLASS
		isTranslucent = true;
	}else if (blockId == BLOCK_WATER){
		matID = 1.0;    // MATID_WATER (should be handled by gbuffers_water)
		isTranslucent = true;
	}else if (blockId == BLOCK_CROSS){
		matID = 4.0;    // MATID_GRASS
	}else if (blockId == BLOCK_TORCH){
		matID = 11.0;   // MATID_TORCH
	}else if (blockId == BLOCK_LANTERN){
		matID = 20.0;   // MATID_COPPER_LANTERN
	}else if (blockId == BLOCK_FIRE || blockId == BLOCK_CAMPFIRE){
		matID = 12.0;   // MATID_FIRE
	}else if (blockId == BLOCK_LAVA){
		matID = 12.0;
	}else if (blockId == BLOCK_GLASS_PANE){
		matID = 2.0;    // MATID_STAINEDGLASS
		isTranslucent = true;
	}else if (blockId == BLOCK_ENDROD){
		matID = 13.0;   // MATID_ENDROD
	}else if (blockId == BLOCK_AMETHYST){
		matID = 14.0;   // MATID_AMETHYST
	}else if (blockId == BLOCK_PORTAL){
		matID = 18.0;   // MATID_END_PORTAL
	}else if (blockId == BLOCK_COBWEB){
		matID = 17.0;   // MATID_PARTICLE-like
		isTranslucent = true;
	}

	// Emissive detection
	float emissive = 0.0;
	#ifdef HARDCODED_EMISSIVENESS_MODE
		if (blockId == BLOCK_LAVA || blockId == BLOCK_FIRE || blockId == BLOCK_CAMPFIRE ||
			blockId == BLOCK_GLOWSTONE || blockId == BLOCK_ENDROD || blockId == BLOCK_LANTERN ||
			blockId == BLOCK_AMETHYST || blockId == BLOCK_TORCH || blockId == BLOCK_CANDLE ||
			blockId == BLOCK_LIGHT || blockId == BLOCK_CONDUIT){
			emissive = 1.0;
		}
	#endif

	#ifdef VANILLA_EMISSIVE
		// Emissive blocks from vanilla light level (at_midBlock.w = 0-15)
		emissive = max(emissive, step(13.5, blockLightLevel) * blockLightLevel / 15.0);
	#endif

	// LAB PBR specular
	vec4 specTex = vec4(0.0);
	#ifdef TEXTURE_PBR_FORMAT
		if (TEXTURE_PBR_FORMAT >= 1 && blockId != BLOCK_WATER){
			specTex = texture(atlasSpecular2D, texcoord);
		}
	#endif

	// Lightmap
	vec2 lm = lightmap;
	lm.y = SkyLightmapCurve(lightmap.y);

	// Parallax shadow (POM)
	float parallaxShadow = 1.0;

	// Encode normals (octahedral)
	vec2 worldNormalEnc = EncodeNormal(worldNormal);
	vec2 vertexNormalEnc = EncodeNormal(vertexNormal);

	// Solid write
	colortex0Out = vec4(albedo.rgb, emissive);
	colortex1Out = vec4(worldNormalEnc, vertexNormalEnc);
	colortex2Out = vec4(specTex.r, specTex.g, specTex.b, matID / 255.0);
	colortex3Out = vec4(lm, parallaxShadow, 1.0);

	// Translucent write (glass, panes, cobweb)
	if (isTranslucent){
		colortex4Out = vec4(albedo.rgb, albedo.a);
		colortex5Out = vec4(worldNormalEnc, matID / 255.0, specTex.r);
	}else{
		colortex4Out = vec4(0.0);
		colortex5Out = vec4(0.0);
	}
}