add bilinear-adjustable (#401)

* add bilinear-adjustable

* add bilinear-adjustable

interpolation/bilinear-adjustable.slangp

@@ -0,0 +1,5 @@
+shaders = 1
+
+shader0 = "shaders/bilinear-adjustable.slang"
+filter_linear0 = true
+scale_type0 = viewport

interpolation/shaders/bilinear-adjustable.slang

@@ -0,0 +1,79 @@
+#version 450
+
+/*
+   April 2023
+   Adjustable Bilinear by DariusG
+
+*/
+#pragma parameter sharp1 "Horizontal Sharpness" 1.0 1.0 10.0 0.1
+#pragma parameter sharp2 "Vertical Sharpness" 1.0 1.0 10.0 0.1
+
+
+layout(push_constant) uniform Push
+{
+	vec4 SourceSize;
+	vec4 OriginalSize;
+	vec4 OutputSize;
+	float sharp1;
+	float sharp2;
+
+} params;
+
+#define sharp1 params.sharp1
+#define sharp2 params.sharp2
+#define SourceSize params.SourceSize
+
+layout(std140, set = 0, binding = 0) uniform UBO
+{
+	mat4 MVP;
+	vec4 FinalViewportSize;
+	vec4 OutputSize;
+} global;
+
+#pragma stage vertex
+layout(location = 0) in vec4 Position;
+layout(location = 1) in vec2 TexCoord;
+layout(location = 0) out vec2 vTexCoord;
+
+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 = 1) uniform sampler2D Source;
+
+
+void main()
+{
+
+vec2 OneTexel = SourceSize.zw;
+
+vec2 OGL2Pos = vTexCoord * SourceSize.xy;
+vec2 pC4 = floor(OGL2Pos) * OneTexel + 0.5*OneTexel;
+
+vec2 coord4 = vec2 (0.0);
+vec2 coord2 = vec2 (OneTexel.x, 0.0 );
+vec2 coord1 = vec2 (0.0, OneTexel.y);
+vec2 coord3 = vec2 (OneTexel.x, OneTexel.y);
+
+
+vec4 s4 = vec4(texture(Source, pC4 + coord4));
+vec4 s2 = vec4(texture(Source, pC4 + coord2));
+vec4 s1 = vec4(texture(Source, pC4 + coord1));
+vec4 s3 = vec4(texture(Source, pC4 + coord3));
+
+float fu = pow(fract(OGL2Pos.x),sharp1);
+float fv = pow(fract(OGL2Pos.y),sharp2);
+
+vec4 tmp1 = mix(s4, s2, fu);
+vec4 tmp2 = mix(s1, s3, fu);
+
+vec4 t0 = mix(tmp1, tmp2, fv);
+
+	FragColor = t0;
+}