slang-shaders/handheld/console-border/shader-files/gb-pass1.slang
2020-07-12 01:49:51 +01:00

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#version 450
layout(push_constant) uniform Push
{
vec4 OutputSize;
vec4 OriginalSize;
vec4 SourceSize;
float blending_mode;
float adjacent_texel_alpha_blending;
} registers;
layout(std140, set = 0, binding = 0) uniform UBO
{
mat4 MVP;
} global;
////////////////////////////////////////////////////////////////////////////////
// Config //
////////////////////////////////////////////////////////////////////////////////
// 0 - only the space between dots is blending
// 1 - all texels are blended
#pragma parameter blending_mode "Blending Mode" 0.0 0.0 1.0 1.0
// The amount of alpha swapped between neighboring texels
#pragma parameter adjacent_texel_alpha_blending "Neighbor Blending" 0.76 0.0 1.0 0.01
///////////////////////////////////////////////////////////////////////////
// //
// Gameboy Classic Shader v0.2.2 //
// //
// Copyright (C) 2013 Harlequin : unknown92835@gmail.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 3 of the License, or //
// (at your option) 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, see <http://www.gnu.org/licenses/>. //
// //
///////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
// Vertex shader //
////////////////////////////////////////////////////////////////////////////////
#pragma stage vertex
layout(location = 0) in vec4 Position;
layout(location = 1) in vec2 TexCoord;
layout(location = 0) out vec2 vTexCoord;
layout(location = 1) out vec2 texel;
layout(location = 2) out vec2 blur_coords_up;
layout(location = 3) out vec2 blur_coords_down;
layout(location = 4) out vec2 blur_coords_right;
layout(location = 5) out vec2 blur_coords_left;
layout(location = 6) out vec2 blur_coords_upright;
layout(location = 7) out vec2 blur_coords_upleft;
layout(location = 8) out vec2 blur_coords_downright;
layout(location = 9) out vec2 blur_coords_downleft;
layout(location = 10) out vec2 blur_coords_lower_bound;
layout(location = 11) out vec2 blur_coords_upper_bound;
void main()
{
gl_Position = global.MVP * Position;
vTexCoord = TexCoord;
texel = registers.SourceSize.zw;
blur_coords_down = vTexCoord + vec2(0.0, texel.y);
blur_coords_up = vTexCoord + vec2(0.0, -texel.y);
blur_coords_right = vTexCoord + vec2(texel.x, 0.0);
blur_coords_left = vTexCoord + vec2(-texel.x, 0.0);
blur_coords_downright = vTexCoord + vec2(texel.x, texel.y);
blur_coords_downleft = vTexCoord + vec2(-texel.x, texel.y);
blur_coords_upright = vTexCoord + vec2(texel.x, -texel.y);
blur_coords_upleft = vTexCoord + vec2(-texel.x, -texel.y);
blur_coords_lower_bound = vec2(0.0);
blur_coords_upper_bound = texel * (registers.OutputSize.xy - vec2(2.0));
}
////////////////////////////////////////////////////////////////////////////////
// Fragment shader //
////////////////////////////////////////////////////////////////////////////////
#pragma stage fragment
layout(location = 0) in vec2 vTexCoord;
layout(location = 1) in vec2 texel;
layout(location = 2) in vec2 blur_coords_up;
layout(location = 3) in vec2 blur_coords_down;
layout(location = 4) in vec2 blur_coords_right;
layout(location = 5) in vec2 blur_coords_left;
layout(location = 6) in vec2 blur_coords_upright;
layout(location = 7) in vec2 blur_coords_upleft;
layout(location = 8) in vec2 blur_coords_downright;
layout(location = 9) in vec2 blur_coords_downleft;
layout(location = 10) in vec2 blur_coords_lower_bound;
layout(location = 11) in vec2 blur_coords_upper_bound;
layout(location = 0) out vec4 FragColor;
layout(set = 0, binding = 2) uniform sampler2D Source;
////////////////////////////////////////////////////////////////////////////////
// Fragment definitions //
////////////////////////////////////////////////////////////////////////////////
// Clamp the blur coords to the input texture size so it doesn't attempt to sample off the texture (it'll retrieve float4(0.0) and darken the edges otherwise)
// Then return its alpha
float clamped_coord_alpha(vec2 blur_coords)
{
vec2 clamped_coord = clamp(blur_coords, blur_coords_lower_bound, blur_coords_upper_bound);
return texture(Source, clamped_coord).a;
}
// Used for gap direction detection
bool is_gap(vec2 coords_side_1, vec2 coords_side_2)
{
float alpha_side_1 = texture(Source, coords_side_1).a;
float alpha_side_2 = texture(Source, coords_side_2).a;
return alpha_side_1 == 0.0 && alpha_side_2 == 0.0;
}
// A simple blur technique that softens harsh color transitions
// Specialized to only blur alpha values
// Blends only the texels between dots
vec4 blend_gap_mode(vec4 out_color)
{
if(out_color.a == 0.0)
{
// Check if our gap is horizontal or vertical
bool is_gap_horizontal = is_gap(blur_coords_left, blur_coords_right);
bool is_gap_vertical = is_gap(blur_coords_up, blur_coords_down);
// When in a gap interesection, average the 4 diagonal dots
if(is_gap_horizontal && is_gap_vertical)
{
// Set the current fragment alpha value to the average of alpha differences between neighboring texels
out_color.a =
(
(clamped_coord_alpha(blur_coords_upleft) - out_color.a) +
(clamped_coord_alpha(blur_coords_upright) - out_color.a) +
(clamped_coord_alpha(blur_coords_downleft) - out_color.a) +
(clamped_coord_alpha(blur_coords_downright) - out_color.a)
) / 4;
}
// When in an horizontal gap, average the above and bellow texels
else if(is_gap_horizontal)
{
out_color.a =
(
(clamped_coord_alpha(blur_coords_up) - out_color.a) +
(clamped_coord_alpha(blur_coords_down) - out_color.a)
) / 2;
}
// When in a vertical gap, average the left and right texels
else if(is_gap_vertical)
{
out_color.a =
(
(clamped_coord_alpha(blur_coords_right) - out_color.a) +
(clamped_coord_alpha(blur_coords_left) - out_color.a)
) / 2;
}
// Modify the alpha value based on how high the "Neighbor Blending" parameter is set to
out_color.a *= registers.adjacent_texel_alpha_blending;
}
return out_color;
}
// Blends all texels
vec4 blend_all_mode(vec4 out_color)
{
// Average the alpha differences between neighboring texels, apply the parameter modifier, then sum the result to the current fragment alpha value
out_color.a +=
(
(clamped_coord_alpha(blur_coords_up) - out_color.a) +
(clamped_coord_alpha(blur_coords_down) - out_color.a) +
(clamped_coord_alpha(blur_coords_right) - out_color.a) +
(clamped_coord_alpha(blur_coords_left) - out_color.a)
) / 4 * registers.adjacent_texel_alpha_blending;
return out_color;
}
void main()
{
vec4 out_color = texture(Source, vTexCoord).rgba;
if(registers.blending_mode == 1.0)
FragColor = blend_all_mode(out_color);
else
FragColor = blend_gap_mode(out_color);
}