slang-shaders/crt/shaders/crt-royale/src/crt-royale-bloom-approx.slang
2016-09-01 11:26:09 -05:00

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#version 450
layout(push_constant) uniform Push
{
vec4 SourceSize;
vec4 OriginalSize;
vec4 OutputSize;
uint FrameCount;
vec4 ORIG_LINEARIZEDSize;
} registers;
#include "params.inc"
///////////////////////////// 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
////////////////////////////////// INCLUDES //////////////////////////////////
#include "../user-settings.h"
#include "derived-settings-and-constants.h"
#include "bind-shader-params.h"
#include "../../../../include/gamma-management.h"
#include "../../../../include/blur-functions.h"
#include "scanline-functions.h"
#include "bloom-functions.h"
/////////////////////////////////// HELPERS //////////////////////////////////
/////////////////////////////////// HELPERS //////////////////////////////////
vec3 tex2Dresize_gaussian4x4(const sampler2D tex, const vec2 tex_uv,
const vec2 dxdy, const vec2 texture_size, const vec2 texture_size_inv,
const vec2 tex_uv_to_pixel_scale, const float sigma)
{
// Requires: 1.) All requirements of gamma-management.h must be satisfied!
// 2.) filter_linearN must == "true" in your .cgp preset.
// 3.) mipmap_inputN must == "true" in your .cgp preset if
// IN.output_size << SRC.video_size.
// 4.) dxdy should contain the uv pixel spacing:
// dxdy = max(vec2(1.0),
// SRC.video_size/IN.output_size)/SRC.texture_size;
// 5.) texture_size == SRC.texture_size
// 6.) texture_size_inv == vec2(1.0)/SRC.texture_size
// 7.) tex_uv_to_pixel_scale == IN.output_size *
// SRC.texture_size / SRC.video_size;
// 8.) sigma is the desired Gaussian standard deviation, in
// terms of output pixels. It should be < ~0.66171875 to
// ensure the first unused sample (outside the 4x4 box) has
// a weight < 1.0/256.0.
// Returns: A true 4x4 Gaussian resize of the input.
// Description:
// Given correct inputs, this Gaussian resizer samples 4 pixel locations
// along each downsized dimension and/or 4 texel locations along each
// upsized dimension. It computes dynamic weights based on the pixel-space
// distance of each sample from the destination pixel. It is arbitrarily
// resizable and higher quality than tex2Dblur3x3_resize, but it's slower.
// TODO: Move this to a more suitable file once there are others like it.
const float denom_inv = 0.5/(sigma*sigma);
// We're taking 4x4 samples, and we're snapping to texels for upsizing.
// Find texture coords for sample 5 (second row, second column):
const vec2 curr_texel = tex_uv * texture_size;
const vec2 prev_texel =
floor(curr_texel - vec2(under_half)) + vec2(0.5);
const vec2 prev_texel_uv = prev_texel * texture_size_inv;
const bvec2 snap = lessThanEqual(dxdy , texture_size_inv);
const vec2 sample5_downsize_uv = tex_uv - 0.5 * dxdy;
const vec2 sample5_uv = mix(sample5_downsize_uv, prev_texel_uv, snap);
// Compute texture coords for other samples:
const vec2 dx = vec2(dxdy.x, 0.0);
const vec2 sample0_uv = sample5_uv - dxdy;
const vec2 sample10_uv = sample5_uv + dxdy;
const vec2 sample15_uv = sample5_uv + 2.0 * dxdy;
const vec2 sample1_uv = sample0_uv + dx;
const vec2 sample2_uv = sample0_uv + 2.0 * dx;
const vec2 sample3_uv = sample0_uv + 3.0 * dx;
const vec2 sample4_uv = sample5_uv - dx;
const vec2 sample6_uv = sample5_uv + dx;
const vec2 sample7_uv = sample5_uv + 2.0 * dx;
const vec2 sample8_uv = sample10_uv - 2.0 * dx;
const vec2 sample9_uv = sample10_uv - dx;
const vec2 sample11_uv = sample10_uv + dx;
const vec2 sample12_uv = sample15_uv - 3.0 * dx;
const vec2 sample13_uv = sample15_uv - 2.0 * dx;
const vec2 sample14_uv = sample15_uv - dx;
// Load each sample:
const vec3 sample0 = tex2D_linearize(tex, sample0_uv).rgb;
const vec3 sample1 = tex2D_linearize(tex, sample1_uv).rgb;
const vec3 sample2 = tex2D_linearize(tex, sample2_uv).rgb;
const vec3 sample3 = tex2D_linearize(tex, sample3_uv).rgb;
const vec3 sample4 = tex2D_linearize(tex, sample4_uv).rgb;
const vec3 sample5 = tex2D_linearize(tex, sample5_uv).rgb;
const vec3 sample6 = tex2D_linearize(tex, sample6_uv).rgb;
const vec3 sample7 = tex2D_linearize(tex, sample7_uv).rgb;
const vec3 sample8 = tex2D_linearize(tex, sample8_uv).rgb;
const vec3 sample9 = tex2D_linearize(tex, sample9_uv).rgb;
const vec3 sample10 = tex2D_linearize(tex, sample10_uv).rgb;
const vec3 sample11 = tex2D_linearize(tex, sample11_uv).rgb;
const vec3 sample12 = tex2D_linearize(tex, sample12_uv).rgb;
const vec3 sample13 = tex2D_linearize(tex, sample13_uv).rgb;
const vec3 sample14 = tex2D_linearize(tex, sample14_uv).rgb;
const vec3 sample15 = tex2D_linearize(tex, sample15_uv).rgb;
// Compute destination pixel offsets for each sample:
const vec2 dest_pixel = tex_uv * tex_uv_to_pixel_scale;
const vec2 sample0_offset = sample0_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample1_offset = sample1_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample2_offset = sample2_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample3_offset = sample3_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample4_offset = sample4_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample5_offset = sample5_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample6_offset = sample6_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample7_offset = sample7_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample8_offset = sample8_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample9_offset = sample9_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample10_offset = sample10_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample11_offset = sample11_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample12_offset = sample12_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample13_offset = sample13_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample14_offset = sample14_uv * tex_uv_to_pixel_scale - dest_pixel;
const vec2 sample15_offset = sample15_uv * tex_uv_to_pixel_scale - dest_pixel;
// Compute Gaussian sample weights:
const float w0 = exp(-LENGTH_SQ(sample0_offset) * denom_inv);
const float w1 = exp(-LENGTH_SQ(sample1_offset) * denom_inv);
const float w2 = exp(-LENGTH_SQ(sample2_offset) * denom_inv);
const float w3 = exp(-LENGTH_SQ(sample3_offset) * denom_inv);
const float w4 = exp(-LENGTH_SQ(sample4_offset) * denom_inv);
const float w5 = exp(-LENGTH_SQ(sample5_offset) * denom_inv);
const float w6 = exp(-LENGTH_SQ(sample6_offset) * denom_inv);
const float w7 = exp(-LENGTH_SQ(sample7_offset) * denom_inv);
const float w8 = exp(-LENGTH_SQ(sample8_offset) * denom_inv);
const float w9 = exp(-LENGTH_SQ(sample9_offset) * denom_inv);
const float w10 = exp(-LENGTH_SQ(sample10_offset) * denom_inv);
const float w11 = exp(-LENGTH_SQ(sample11_offset) * denom_inv);
const float w12 = exp(-LENGTH_SQ(sample12_offset) * denom_inv);
const float w13 = exp(-LENGTH_SQ(sample13_offset) * denom_inv);
const float w14 = exp(-LENGTH_SQ(sample14_offset) * denom_inv);
const float w15 = exp(-LENGTH_SQ(sample15_offset) * denom_inv);
const float weight_sum_inv = 1.0/(
w0 + w1 + w2 + w3 + w4 + w5 + w6 + w7 +
w8 +w9 + w10 + w11 + w12 + w13 + w14 + w15);
// Weight and sum the samples:
const vec3 sum = w0 * sample0 + w1 * sample1 + w2 * sample2 + w3 * sample3 +
w4 * sample4 + w5 * sample5 + w6 * sample6 + w7 * sample7 +
w8 * sample8 + w9 * sample9 + w10 * sample10 + w11 * sample11 +
w12 * sample12 + w13 * sample13 + w14 * sample14 + w15 * sample15;
return sum * weight_sum_inv;
}
#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 float estimated_viewport_size_x;
layout(location = 2) out vec2 blur_dxdy;
layout(location = 3) out vec2 uv_scanline_step;
layout(location = 4) out vec2 texture_size_inv;
layout(location = 5) out vec2 tex_uv_to_pixel_scale;
void main()
{
// This vertex shader copies blurs/vertex-shader-blur-one-pass-resize.h,
// except we're using a different source image.
gl_Position = params.MVP * Position;
const vec2 video_uv = TexCoord;
tex_uv = video_uv;
// The last pass (vertical scanlines) had a viewport y scale, so we can
// use it to calculate a better runtime sigma:
estimated_viewport_size_x = registers.SourceSize.y * params.geom_aspect_ratio_x / params.geom_aspect_ratio_y;
// Get the uv sample distance between output pixels. We're using a resize
// blur, so arbitrary upsizing will be acceptable if filter_linearN =
// "true," and arbitrary downsizing will be acceptable if mipmap_inputN =
// "true" too. The blur will be much more accurate if a true 4x4 Gaussian
// resize is used instead of tex2Dblur3x3_resize (which samples between
// texels even for upsizing).
const vec2 dxdy_min_scale = registers.ORIG_LINEARIZEDSize.xy * registers.OutputSize.zw;
texture_size_inv = registers.ORIG_LINEARIZEDSize.zw;
if(bloom_approx_filter > 1.5) // 4x4 true Gaussian resize
{
// For upsizing, we'll snap to texels and sample the nearest 4.
const vec2 dxdy_scale = max(dxdy_min_scale, vec2(1.0));
blur_dxdy = dxdy_scale * texture_size_inv;
}
else
{
const vec2 dxdy_scale = dxdy_min_scale;
blur_dxdy = dxdy_scale * texture_size_inv;
}
tex_uv_to_pixel_scale = registers.OutputSize.xy;
// texture_size_inv = texture_size_inv; <- commented out because it's pointless in slang
// Detecting interlacing again here lets us apply convergence offsets in
// this pass. il_step_multiple contains the (texel, scanline) step
// multiple: 1 for progressive, 2 for interlaced.
const vec2 orig_video_size = registers.ORIG_LINEARIZEDSize.xy;
float interlace_check = 0.0;
if (is_interlaced(orig_video_size.y) == true) interlace_check = 1.0;
const float y_step = 1.0 + interlace_check;
const vec2 il_step_multiple = vec2(1.0, y_step);
// Get the uv distance between (texels, same-field scanlines):
uv_scanline_step = il_step_multiple * registers.ORIG_LINEARIZEDSize.zw;
}
#pragma stage fragment
layout(location = 0) in vec2 tex_uv;
layout(location = 1) in float estimated_viewport_size_x;
layout(location = 2) in vec2 blur_dxdy;
layout(location = 3) in vec2 uv_scanline_step;
layout(location = 4) in vec2 texture_size_inv;
layout(location = 5) in vec2 tex_uv_to_pixel_scale;
layout(location = 0) out vec4 FragColor;
layout(set = 0, binding = 2) uniform sampler2D Source;
layout(set = 0, binding = 3) uniform sampler2D ORIG_LINEARIZED;
void main()
{
// Would a viewport-relative size work better for this pass? (No.)
// PROS:
// 1.) Instead of writing an absolute size to user-cgp-constants.h, we'd
// write a viewport scale. That number could be used to directly scale
// the viewport-resolution bloom sigma and/or triad size to a smaller
// scale. This way, we could calculate an optimal dynamic sigma no
// matter how the dot pitch is specified.
// CONS:
// 1.) Texel smearing would be much worse at small viewport sizes, but
// performance would be much worse at large viewport sizes, so there
// would be no easy way to calculate a decent scale.
// 2.) Worse, we could no longer get away with using a constant-size blur!
// Instead, we'd have to face all the same difficulties as the real
// phosphor bloom, which requires static #ifdefs to decide the blur
// size based on the expected triad size...a dynamic value.
// 3.) Like the phosphor bloom, we'd have less control over making the blur
// size correct for an optical blur. That said, we likely overblur (to
// maintain brightness) more than the eye would do by itself: 20/20
// human vision distinguishes ~1 arc minute, or 1/60 of a degree. The
// highest viewing angle recommendation I know of is THX's 40.04 degree
// recommendation, at which 20/20 vision can distinguish about 2402.4
// lines. Assuming the "TV lines" definition, that means 1201.2
// distinct light lines and 1201.2 distinct dark lines can be told
// apart, i.e. 1201.2 pairs of lines. This would correspond to 1201.2
// pairs of alternating lit/unlit phosphors, so 2402.4 phosphors total
// (if they're alternately lit). That's a max of 800.8 triads. Using
// a more popular 30 degree viewing angle recommendation, 20/20 vision
// can distinguish 1800 lines, or 600 triads of alternately lit
// phosphors. In contrast, we currently blur phosphors all the way
// down to 341.3 triads to ensure full brightness.
// 4.) Realistically speaking, we're usually just going to use bilinear
// filtering in this pass anyway, but it only works well to limit
// bandwidth if it's done at a small constant scale.
// Get the constants we need to sample:
const vec2 texture_size = registers.ORIG_LINEARIZEDSize.xy;
vec2 tex_uv_r, tex_uv_g, tex_uv_b;
if(beam_misconvergence = true)
{
const vec2 convergence_offsets_r = get_convergence_offsets_r_vector();
const vec2 convergence_offsets_g = get_convergence_offsets_g_vector();
const vec2 convergence_offsets_b = get_convergence_offsets_b_vector();
tex_uv_r = tex_uv - vec2(params.convergence_offset_x_r, params.convergence_offset_y_r) * uv_scanline_step;
tex_uv_g = tex_uv - vec2(params.convergence_offset_x_g, params.convergence_offset_y_g) * uv_scanline_step;
tex_uv_b = tex_uv - vec2(params.convergence_offset_x_b, params.convergence_offset_y_b) * uv_scanline_step;
}
// Get the blur sigma:
const float bloom_approx_sigma = get_bloom_approx_sigma(registers.OutputSize.x, estimated_viewport_size_x);
// Sample the resized and blurred texture, and apply convergence offsets if
// necessary. Applying convergence offsets here triples our samples from
// 16/9/1 to 48/27/3, but faster and easier than sampling BLOOM_APPROX and
// HALATION_BLUR 3 times at full resolution every time they're used.
vec3 color_r, color_g, color_b, color;
if(bloom_approx_filter > 1.5)
{
// Use a 4x4 Gaussian resize. This is slower but technically correct.
if(beam_misconvergence = true)
{
color_r = tex2Dresize_gaussian4x4(ORIG_LINEARIZED, tex_uv_r,
blur_dxdy, texture_size, texture_size_inv,
tex_uv_to_pixel_scale, bloom_approx_sigma);
color_g = tex2Dresize_gaussian4x4(ORIG_LINEARIZED, tex_uv_g,
blur_dxdy, texture_size, texture_size_inv,
tex_uv_to_pixel_scale, bloom_approx_sigma);
color_b = tex2Dresize_gaussian4x4(ORIG_LINEARIZED, tex_uv_b,
blur_dxdy, texture_size, texture_size_inv,
tex_uv_to_pixel_scale, bloom_approx_sigma);
}
else
{
color = tex2Dresize_gaussian4x4(ORIG_LINEARIZED, tex_uv,
blur_dxdy, texture_size, texture_size_inv,
tex_uv_to_pixel_scale, bloom_approx_sigma);
}
}
else if(bloom_approx_filter > 0.5)
{
// Use a 3x3 resize blur. This is the softest option, because we're
// blurring already blurry bilinear samples. It doesn't play quite as
// nicely with convergence offsets, but it has its charms.
if(beam_misconvergence = true)
{
color_r = tex2Dblur3x3resize(ORIG_LINEARIZED, tex_uv_r,
blur_dxdy, bloom_approx_sigma);
color_g = tex2Dblur3x3resize(ORIG_LINEARIZED, tex_uv_g,
blur_dxdy, bloom_approx_sigma);
color_b = tex2Dblur3x3resize(ORIG_LINEARIZED, tex_uv_b,
blur_dxdy, bloom_approx_sigma);
}
else
{
color = tex2Dblur3x3resize(ORIG_LINEARIZED, tex_uv, blur_dxdy);
}
}
else
{
// Use bilinear sampling. This approximates a 4x4 Gaussian resize MUCH
// better than tex2Dblur3x3_resize for the very small sigmas we're
// likely to use at small output resolutions. (This estimate becomes
// too sharp above ~400x300, but the blurs break down above that
// resolution too, unless min_allowed_viewport_triads is high enough to
// keep bloom_approx_scale_x/min_allowed_viewport_triads < ~1.1658025.)
if(beam_misconvergence = true)
{
color_r = tex2D_linearize(ORIG_LINEARIZED, tex_uv_r).rgb;
color_g = tex2D_linearize(ORIG_LINEARIZED, tex_uv_g).rgb;
color_b = tex2D_linearize(ORIG_LINEARIZED, tex_uv_b).rgb;
}
else
{
color = tex2D_linearize(ORIG_LINEARIZED, tex_uv).rgb;
}
}
// Pack the colors from the red/green/blue beams into a single vector:
if(beam_misconvergence = true)
{
color = vec3(color_r.r, color_g.g, color_b.b);
}
// Encode and output the blurred image:
FragColor = vec4(color, 1.0);
}