From f0c2969e7474b9027b145396fc1721ab0c1c09d3 Mon Sep 17 00:00:00 2001
From: Arzed Five <rz5@users.noreply.github.com>
Date: Sun, 7 Aug 2016 18:42:11 +0100
Subject: [PATCH] (retro) Ported retro-v2 and the respective preset.

---
 retro/retro-v2.slangp        |  5 +++
 retro/shaders/retro-v2.slang | 78 ++++++++++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+)
 create mode 100644 retro/retro-v2.slangp
 create mode 100644 retro/shaders/retro-v2.slang

diff --git a/retro/retro-v2.slangp b/retro/retro-v2.slangp
new file mode 100644
index 0000000..ad5e08a
--- /dev/null
+++ b/retro/retro-v2.slangp
@@ -0,0 +1,5 @@
+shaders = 1
+
+shader0 = shaders/retro-v2.slang
+filter_linear0 = false
+scale_type_0 = source
diff --git a/retro/shaders/retro-v2.slang b/retro/shaders/retro-v2.slang
new file mode 100644
index 0000000..f8af755
--- /dev/null
+++ b/retro/shaders/retro-v2.slang
@@ -0,0 +1,78 @@
+#version 450
+
+/*
+   Hyllian - Retro Shader - 2013
+
+   A re-implementation from the original made by Hyllian and DOLLS!
+   
+   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 (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, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+*/
+
+layout(push_constant) uniform Push
+{
+    float RETRO_PIXEL_SIZE;
+} param;
+
+// This value must be between 0.0 (totally black) and 1.0 (nearest neighbor)
+#pragma parameter RETRO_PIXEL_SIZE "Retro Pixel Size" 0.84 0.0 1.0 0.01
+
+layout(std140, set = 0, binding = 0) uniform UBO
+{
+    mat4 MVP;
+    vec4 OutputSize;
+    vec4 OriginalSize;
+    vec4 SourceSize;
+} global;
+
+#pragma stage vertex
+layout(location = 0) in vec4 Position;
+layout(location = 1) in vec2 TexCoord;
+layout(location = 0) out vec2 vTexCoord;
+
+/*
+    VERTEX_SHADER
+*/
+void main()
+{
+    gl_Position = global.MVP * Position;
+    vTexCoord   = TexCoord;
+}
+
+#pragma stage fragment
+layout(location = 0) in vec2 vTexCoord;
+layout(location = 0) out vec4 FragColor;
+layout(set = 0, binding = 2) uniform sampler2D Source;
+
+/*
+    FRAGMENT SHADER
+*/
+void main()
+{
+    // Reading the texel
+    vec3 E = pow(texture(Source, vTexCoord).xyz, vec3(2.4));
+
+    vec2 fp = fract(vTexCoord*global.SourceSize.xy);
+    vec2 ps = global.SourceSize.xy * global.OutputSize.zw;
+
+    vec2 f = clamp(clamp(fp + 0.5*ps, 0.0, 1.0) - param.RETRO_PIXEL_SIZE, vec2(0.0), ps)/ps;
+
+    float max_coord =  max(f.x, f.y);
+
+    vec3 res = mix(E*(1.04+fp.x*fp.y), E*0.36, max_coord);
+
+    // Product interpolation
+    FragColor = vec4(clamp( pow(res, vec3(1.0 / 2.2)), 0.0, 1.0 ), 1.0);
+}