Add cheap-sharpen shader

A lightweight sharpen shader with anti-ringing.

sharpen/cheap-sharpen.slangp

@@ -0,0 +1,6 @@
+shaders = 1
+
+shader0 = shaders/cheap-sharpen.slang
+filter_linear0 = false
+scale_type0 = source
+scale0 = 1.0

sharpen/shaders/cheap-sharpen.slang

@@ -0,0 +1,96 @@
+#version 450
+
+/*
+   Hyllian cheap sharpen Shader
+  
+   Copyright (C) 2011-2024 Hyllian - sergiogdb@gmail.com
+
+   Permission is hereby granted, free of charge, to any person obtaining a copy
+   of this software and associated documentation files (the "Software"), to deal
+   in the Software without restriction, including without limitation the rights
+   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+   copies of the Software, and to permit persons to whom the Software is
+   furnished to do so, subject to the following conditions:
+   The above copyright notice and this permission notice shall be included in
+   all copies or substantial portions of the Software.
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+   THE SOFTWARE.
+*/
+
+layout(push_constant) uniform Push
+{
+    vec4 SourceSize;
+    vec4 OriginalSize;
+    vec4 OutputSize;
+    uint FrameCount;
+    float CS_SHARPNESS;
+} params;
+
+#pragma parameter CS_SHARPNESS "Sharpness" 0.4 0.0 1.0 0.1  
+
+#define CS_SHARPNESS params.CS_SHARPNESS
+
+layout(std140, set = 0, binding = 0) uniform UBO
+{
+    mat4 MVP;
+} global;
+
+#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 vec4 t1;
+layout(location = 2) out vec4 t2;
+
+void main()
+{
+    gl_Position = global.MVP * Position;
+    vTexCoord = TexCoord;
+    float dx = params.SourceSize.z;
+    float dy = params.SourceSize.w;
+
+    t1 = vTexCoord.xyyy + vec4( 0.0, -dy, 0.0,  dy); //  B E H
+    t2 = vTexCoord.xxxy + vec4( -dx, 0.0,  dx, 0.0); //  D E F
+}
+
+#pragma stage fragment
+layout(location = 0) in vec2 vTexCoord;
+layout(location = 1) in vec4 t1;
+layout(location = 2) in vec4 t2;
+layout(location = 3) in vec4 t3;
+layout(location = 0) out vec4 FragColor;
+layout(set = 0, binding = 2) uniform sampler2D Source;
+
+
+/*       
+              B   
+           D  E  F 
+              H   
+*/
+
+void main()
+{
+    vec3   B = texture(Source, t1.xy).xyz;
+    vec3   D = texture(Source, t2.xw).xyz;
+    vec3   E = texture(Source, t2.yw).xyz;
+    vec3   F = texture(Source, t2.zw).xyz;
+    vec3   H = texture(Source, t1.xw).xyz;
+
+    vec3 color = (1.0 + CS_SHARPNESS) * E - 0.25 * CS_SHARPNESS * (B + D + F + H);
+
+    // Anti-ringing
+    //  Get min/max samples
+    vec3 min_sample = min(min(E,min(D,F)), min(B,H));
+    vec3 max_sample = max(max(E,max(D,F)), max(B,H));
+
+    vec3 aux = color;
+    color = clamp(color, min_sample, max_sample);
+    color = mix(aux, color, step(-0.00001, (E-D)*(F-E) + (E-B)*(H-E)));
+
+    FragColor = vec4(color, 1.0);
+}