add ascii art shader and fix ds-hybrid

handheld/shaders/ds-hybrid-view.slang

@@ -14,7 +14,7 @@ layout(push_constant) uniform Push
 	vec4 OutputSize;
 	uint FrameCount;
 	float screen_toggle;
-	float scale_correction;
+	float aspect_correction;
 } params;
 
 #pragma parameter screen_toggle "Screen Toggle" 0.0 0.0 0.5 0.5

retro/shaders/ascii.slang

@@ -0,0 +1,66 @@
+#version 450
+
+// Bitmap to ASCII (not really) fragment shader by movAX13h, September 2013
+// --- This shader is now used in Pixi JS ---
+// Pixi JS is MIT-licensed
+
+layout(push_constant) uniform Push
+{
+	vec4 SourceSize;
+	vec4 OriginalSize;
+	vec4 OutputSize;
+	uint FrameCount;
+} params;
+
+layout(std140, set = 0, binding = 0) uniform UBO
+{
+	mat4 MVP;
+} global;
+
+float character(float n, vec2 p) // some compilers have the word "char" reserved
+{
+	p = floor(p*vec2(4.0, -4.0) + 2.5);
+	if (clamp(p.x, 0.0, 4.0) == p.x && clamp(p.y, 0.0, 4.0) == p.y)
+	{
+		if (int(mod(n/exp2(p.x + 5.0*p.y), 2.0)) == 1) return 1.0;
+	}	
+	return 0.0;
+}
+
+#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 = 2) uniform sampler2D Source;
+
+void main()
+{
+	vec2 uv = gl_FragCoord.xy;
+	vec3 col = texture(Source, floor(uv/8.0)*8.0/params.OutputSize.xy + vec2(-0.21, 0.0)).rgb;	
+	
+	float gray = dot(col.rgb, vec3(0.299, 0.587, 0.114));
+	
+	float n =  65536.0;             // .
+	if (gray > 0.2) n = 65600.0;    // :
+	if (gray > 0.3) n = 332772.0;   // *
+	if (gray > 0.4) n = 15255086.0; // o 
+	if (gray > 0.5) n = 23385164.0; // &
+	if (gray > 0.6) n = 15252014.0; // 8
+	if (gray > 0.7) n = 13199452.0; // @
+	if (gray > 0.8) n = 11512810.0; // #
+	
+	vec2 p = mod(uv/4.0, 2.0) - vec2(1.0);
+	col = col*character(n, p);
+	
+   FragColor = vec4(col, 1.0);
+}