#version 450

/////////////////////////////  GPL LICENSE NOTICE  /////////////////////////////

//  crt-royale: A full-featured CRT shader, with cheese.
//  Copyright (C) 2014 TroggleMonkey <trogglemonkey@gmx.com>
//
//  This program is free software; you can redistribute it and/or modify it
//  under the terms of the GNU General Public License as published by the Free
//  Software Foundation; either version 2 of the License, or any later version.
//
//  This program is distributed in the hope that it will be useful, but WITHOUT
//  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
//  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
//  more details.
//
//  You should have received a copy of the GNU General Public License along with
//  this program; if not, write to the Free Software Foundation, Inc., 59 Temple
//  Place, Suite 330, Boston, MA 02111-1307 USA

layout(push_constant) uniform Push
{
	vec4 SourceSize;
	vec4 OriginalSize;
	vec4 OutputSize;
	uint FrameCount;
	vec4 MASKED_SCANLINESSize;
	vec4 BLOOM_APPROXSize;
} params;

/////////////////////////////  SETTINGS MANAGEMENT  ////////////////////////////

#include "../../../../include/compat_macros.inc"
#include "../user-settings.h"
#include "derived-settings-and-constants.h"
#include "bind-shader-params.h"


///////////////////////////////  VERTEX INCLUDES  ///////////////////////////////

#include "../../../../include/gamma-management.h"
#include "phosphor-mask-resizing.h"

float bloom_approx_scale_x = params.OutputSize.x / params.SourceSize.y;
const float max_viewport_size_x = 1080.0*1024.0*(4.0/3.0);
const float bloom_diff_thresh_ = 1.0/256.0;

#pragma stage vertex
layout(location = 0) in vec4 Position;
layout(location = 1) in vec2 TexCoord;
layout(location = 0) out vec2 tex_uv;
layout(location = 1) out vec2 bloom_dxdy;
layout(location = 2) out float bloom_sigma_runtime;

// copied from bloom-functions.h
inline float get_min_sigma_to_blur_triad(const float triad_size,
    const float thresh)
{
    //  Requires:   1.) triad_size is the final phosphor triad size in pixels
    //              2.) thresh is the max desired pixel difference in the
    //                  blurred triad (e.g. 1.0/256.0).
    //  Returns:    Return the minimum sigma that will fully blur a phosphor
    //              triad on the screen to an even color, within thresh.
    //              This closed-form function was found by curve-fitting data.
    //  Estimate: max error = ~0.086036, mean sq. error = ~0.0013387:
    return -0.05168 + 0.6113*triad_size -
        1.122*triad_size*sqrt(0.000416 + thresh);
    //  Estimate: max error = ~0.16486, mean sq. error = ~0.0041041:
    //return 0.5985*triad_size - triad_size*sqrt(thresh)
}

void main()
{
   gl_Position = global.MVP * Position;
   tex_uv = TexCoord * 1.0001;
   
	//  Get the uv sample distance between output pixels.  Calculate dxdy like
    //  blurs/shaders/vertex-shader-blur-fast-vertical.h.
    const float2 dxdy_scale = IN.video_size/IN.output_size;
    const float2 dxdy = dxdy_scale/IN.texture_size;
    //  This blur is vertical-only, so zero out the vertical offset:
    bloom_dxdy = float2(0.0, dxdy.y);

    //  Calculate a runtime bloom_sigma in case it's needed:
    const float mask_tile_size_x = get_resized_mask_tile_size(
        IN.output_size, IN.output_size * mask_resize_viewport_scale, false).x;
    bloom_sigma_runtime = get_min_sigma_to_blur_triad(
        mask_tile_size_x / mask_triads_per_tile, bloom_diff_thresh_);
}

#pragma stage fragment
#pragma format R8G8B8A8_SRGB
layout(location = 0) in vec2 tex_uv;
layout(location = 1) in vec2 bloom_dxdy;
layout(location = 2) in float bloom_sigma_runtime;
layout(location = 0) out vec4 FragColor;
layout(set = 0, binding = 2) uniform sampler2D Source;
#define input_texture Source

//////////////////////////////  FRAGMENT INCLUDES  //////////////////////////////

#include "bloom-functions.h"

void main()
{
    //  Blur the brightpass horizontally with a 9/17/25/43x blur:
    const float bloom_sigma = get_final_bloom_sigma(bloom_sigma_runtime);
    const float3 color = tex2DblurNfast(input_texture, tex_uv,
        bloom_dxdy, bloom_sigma);
    //  Encode and output the blurred image:
    FragColor = encode_output(float4(color, 1.0));
}