//======= Copyright (c) 2015-2020 Vera Visions LLC. All rights reserved. =======
//
// Purpose: 
//
// Lightgrid-lit surface, normalmap's alpha contains specularity information.
//==============================================================================

!!ver 110
!!permu FRAMEBLEND
!!permu FOG
!!permu SKELETAL
!!cvarf gl_specular
!!samps diffuse fullbright normalmap

!!permu FAKESHADOWS
!!cvardf r_glsl_pcf
!!samps =FAKESHADOWS shadowmap

!!cvardf r_skipDiffuse
!!cvardf r_skipSpecular
!!cvardf r_skipNormal

#include "sys/defs.h"

varying vec2 tex_c;
varying vec3 eyevector;
varying vec3 norm;
varying mat3 invsurface;

#ifdef FAKESHADOWS
	varying vec4 vtexprojcoord;
#endif

#ifdef VERTEX_SHADER
	#include "sys/skeletal.h"

#ifdef CHROME
	/* Rotate Light Vector */
	vec3 rlv(vec3 axis, vec3 origin, vec3 lightpoint)
	{
		vec3 offs;
		vec3 result;
		offs[0] = lightpoint[0] - origin[0];
		offs[1] = lightpoint[1] - origin[1];
		offs[2] = lightpoint[2] - origin[2];
		result[0] = dot(offs[0], axis[0]);
		result[1] = dot(offs[1], axis[1]);
		result[2] = dot(offs[2], axis[2]);
		return result;
	}
#endif

	void main ()
	{
		vec3 n, s, t, w;
		gl_Position = skeletaltransform_wnst(w,n,s,t);
		norm = n;
		n = normalize(n);
		s = normalize(s);
		t = normalize(t);

		#ifdef CHROME
		vec3 rorg = rlv(vec3(0,0,0), w, e_eyepos);
		vec3 viewc = normalize(e_eyepos - w);
		float d = dot(n, viewc);
		vec3 reflected;
		reflected.x = n.x * 2.0 * d - viewc.x;
		reflected.y = n.y * 2.0 * d - viewc.y;
		reflected.z = n.z * 2.0 * d - viewc.z;
		tex_c.x = 0.5 + reflected.y * 0.5;
		tex_c.y = 0.5 - reflected.z * 0.5;
		#else
		tex_c = v_texcoord;
		#endif

		/* normalmap */
		invsurface = mat3(s, t, n);

		/* reflect */
		eyevector = e_eyepos - w.xyz;
		
		#ifdef FAKESHADOWS
		vtexprojcoord = (l_cubematrix*vec4(v_position.xyz, 1.0));
		#endif
	}
#endif

#ifdef FRAGMENT_SHADER
	#include "sys/fog.h"
	#include "sys/pcf.h"

#ifdef HALFLAMBERT
	float lambert(vec3 normal, vec3 dir)
	{
		return (lambert(normal, dir) * 0.5) + 0.5;
	}
#else
	float lambert(vec3 normal, vec3 dir)
	{
		return max(dot(normal, dir), 0.0);
	}
#endif
	
	void main ()
	{
		vec4 fb_f = texture2D(s_fullbright, tex_c);
		vec3 light;

	#if r_skipDiffuse==0
		vec4 diffuse_f = texture2D(s_diffuse, tex_c);
	#else
		vec4 diffuse_f = vec4(1.0,1.0,1.0,1.0);
	#endif

	#if r_skipNormal==0
		vec3 normal_f = (texture2D(s_normalmap, tex_c).rgb - 0.5) * 2.0;
		float gloss = texture2D(s_normalmap, tex_c).a;
	#else
		#define normal_f vec3(0.0,0.0,1.0)
		float gloss = texture2D(s_normalmap, tex_c).a;
	#endif

		if (diffuse_f.a < 0.5) {
			discard;
		}

		light = (e_light_mul * lambert(norm, e_light_dir)) * 2.0; /* directional light */
		light += (e_light_ambient * lambert(norm, reflect(norm, e_light_dir))) * 0.5; /* reverse ambient */
		light *= 2.0;

	#if r_skipSpecular==0
		vec3 halfdir = normalize(normalize(eyevector) + e_light_dir);
		vec3 bumps = normalize(invsurface * (normal_f));
		float spec = pow(max(dot(halfdir, bumps), 0.0), FTE_SPECULAR_EXPONENT);
		spec *= 5.0 * (1.0 - gloss);
		diffuse_f.rgb += spec;
	#endif

		diffuse_f.rgb *= light;
		diffuse_f.rgb += fb_f.rgb;

	#ifdef FAKESHADOWS
		diffuse_f.rgb *= ShadowmapFilter(s_shadowmap, vtexprojcoord);
	#endif

		gl_FragColor = fog4( diffuse_f * e_colourident ) * e_lmscale;
	}
#endif