#include "fragmentVersionCentroidUV.h"
#include "uniformEntityConstants.h"
#include "uniformShaderConstants.h"
#include "util.h"

LAYOUT_BINDING(0) uniform sampler2D TEXTURE_0;
LAYOUT_BINDING(1) uniform sampler2D TEXTURE_1;

#ifdef USE_MULTITEXTURE
LAYOUT_BINDING(2) uniform sampler2D TEXTURE_2;
#endif

varying vec4 light;
varying vec4 fogColor;

#ifdef COLOR_BASED
varying vec4 vertColor;
#endif

#ifdef USE_OVERLAY
varying highp vec4 overlayColor;
#endif

#ifdef TINTED_ALPHA_TEST
varying float alphaTestMultiplier;
#endif

#ifdef GLINT
varying vec2 layer1UV;
varying vec2 layer2UV;
varying vec4 tileLightColor;
varying vec4 glintColor;
#endif

vec4 glintBlend(vec4 dest, vec4 source) {
return vec4(source.rgb * source.rgb, source.a) + vec4(dest.rgb, 0.0);
}

#ifdef USE_EMISSIVE
#ifdef USE_ONLY_EMISSIVE
#define NEEDS_DISCARD(C) (C.a == 0.0 || C.a == 1.0 )
#else
#define NEEDS_DISCARD(C)	(C.a + C.r + C.g + C.b == 0.0)
#endif
#else
#ifndef USE_COLOR_MASK
#define NEEDS_DISCARD(C)	(C.a < 0.5)
#else
#define NEEDS_DISCARD(C)	(C.a == 0.0)
#endif
#endif

void main() {
vec4 color = vec4(1.0);

#ifndef NO_TEXTURE
#if !defined(TEXEL_AA) || !defined(TEXEL_AA_FEATURE)
color = texture2D(TEXTURE_0, uv);
#else
color = texture2D_AA(TEXTURE_0, uv);
#endif

#ifdef MASKED_MULTITEXTURE
vec4 tex1 = texture2D(TEXTURE_1, uv);

float maskedTexture = ceil(dot(tex1.rgb, vec3(1.0, 1.0, 1.0)) * (1.0 - tex1.a));
color = mix(tex1, color, clamp(maskedTexture, 0.0, 1.0));
#endif // MASKED_MULTITEXTURE

#if defined(ALPHA_TEST) && !defined(USE_MULTITEXTURE) && !defined(MULTIPLICATIVE_TINT)
if(NEEDS_DISCARD(color))
discard;
#endif // ALPHA_TEST

#ifdef TINTED_ALPHA_TEST
vec4 testColor = color;
testColor.a *= alphaTestMultiplier;
if(NEEDS_DISCARD(testColor))
discard;
#endif // TINTED_ALPHA_TEST
#endif // NO_TEXTURE

#ifdef COLOR_BASED
color *= vertColor;
#endif

#ifdef MULTI_COLOR_TINT
vec2 colorMask = color.rg;

color.rgb = colorMask.rrr * CHANGE_COLOR.rgb;

color.rgb = mix(color, colorMask.gggg * MULTIPLICATIVE_TINT_CHANGE_COLOR, ceil(colorMask.g)).rgb;
#else

#ifdef USE_COLOR_MASK
color.rgb = mix(color.rgb, color.rgb*CHANGE_COLOR.rgb, color.a);
color.a *= CHANGE_COLOR.a;
#endif

#ifdef ITEM_IN_HAND
color.rgb = mix(color.rgb, color.rgb*CHANGE_COLOR.rgb, vertColor.a);
#if defined(MCPE_PLATFORM_NX) && defined(NO_TEXTURE) && defined(GLINT)

vec3 dummyColor = texture2D(TEXTURE_0, vec2(0.0, 0.0)).rgb;
color.rgb += dummyColor * 0.000000001;
#endif
#endif // MULTI_COLOR_TINT

#endif

#ifdef USE_MULTITEXTURE
vec4 tex1 = texture2D(TEXTURE_1, uv);
vec4 tex2 = texture2D(TEXTURE_2, uv);
color.rgb = mix(color.rgb, tex1.rgb, tex1.a);
#ifdef ALPHA_TEST
if (color.a < 0.5 && tex1.a == 0.0) {
discard;
}
#endif

#ifdef COLOR_SECOND_TEXTURE
if (tex2.a > 0.0) {
color.rgb = tex2.rgb + (tex2.rgb * CHANGE_COLOR.rgb - tex2.rgb)*tex2.a;
}
#else
color.rgb = mix(color.rgb, tex2.rgb, tex2.a);
#endif
#endif

#ifdef MULTIPLICATIVE_TINT
vec4 tintTex = texture2D(TEXTURE_1, uv);
#ifdef MULTIPLICATIVE_TINT_COLOR
tintTex.rgb = tintTex.rgb * MULTIPLICATIVE_TINT_CHANGE_COLOR.rgb;
#endif

#ifdef ALPHA_TEST
color.rgb = mix(color.rgb, tintTex.rgb, tintTex.a);
if (color.a + tintTex.a <= 0.0) {
discard;
}
#endif

#endif

#ifdef USE_OVERLAY
//use either the diffuse or the OVERLAY_COLOR
color.rgb = mix(color, overlayColor, overlayColor.a).rgb;
#endif

#ifdef USE_EMISSIVE
//make glowy stuff
color *= mix(vec4(1.0), light, color.a);
#else
color *= light;
#endif

//apply fog
color.rgb = mix(color.rgb, fogColor.rgb, fogColor.a);

#ifdef GLINT
// Applies color mask to glint texture instead and blends with original color
vec4 layer1 = texture2D(TEXTURE_1, fract(layer1UV)).rgbr * glintColor;
vec4 layer2 = texture2D(TEXTURE_1, fract(layer2UV)).rgbr * glintColor;
vec4 glint = (layer1 + layer2) * tileLightColor;

color = glintBlend(color, glint);
#endif

//WARNING do not refactor this
#ifdef UI_ENTITY
color.a *= HUD_OPACITY;
#endif
gl_FragColor = color;
}
