Added LCD graphics filter; emulates low-resolution LCD artifacts

Cocoa/GBPreferencesWindow.m

@@ -28,6 +28,7 @@
                     @"NearestNeighbor",
                     @"Bilinear",
                     @"SmoothBilinear",
+                    @"LCD",
                     @"Scale2x",
                     @"Scale4x",
                     @"AAScale2x",

Cocoa/Preferences.xib

@@ -35,7 +35,7 @@
                     <popUpButton verticalHuggingPriority="750" fixedFrame="YES" translatesAutoresizingMaskIntoConstraints="NO" id="6pP-kK-EEC">
                         <rect key="frame" x="30" y="474" width="245" height="26"/>
                         <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
-                        <popUpButtonCell key="cell" type="push" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" borderStyle="borderAndBezel" imageScaling="proportionallyDown" inset="2" id="I1w-05-lGl">
+                        <popUpButtonCell key="cell" type="push" title="Nearest Neighbor (Pixelated)" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" borderStyle="borderAndBezel" imageScaling="proportionallyDown" inset="2" selectedItem="neN-eo-LA7" id="I1w-05-lGl">
                             <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                             <font key="font" metaFont="menu"/>
                             <menu key="menu" id="xDC-0T-Qg9">
@@ -45,6 +45,7 @@
                                     </menuItem>
                                     <menuItem title="Bilinear (Blurry)" id="iDe-si-atu"/>
                                     <menuItem title="Smooth Bilinear (Less blurry)" id="1jN-pO-1iD"/>
+                                    <menuItem title="LCD Display" id="b8u-LZ-UQf"/>
                                     <menuItem title="Scale2x" id="C1I-L2-Up1"/>
                                     <menuItem title="Scale4x" id="uWA-Zp-JY9"/>
                                     <menuItem title="Anti-aliased Scale2x" id="iP6-DJ-CVH"/>
@@ -119,15 +120,15 @@
                     <popUpButton verticalHuggingPriority="750" fixedFrame="YES" translatesAutoresizingMaskIntoConstraints="NO" id="7fg-Ww-JjR">
                         <rect key="frame" x="30" y="286" width="245" height="26"/>
                         <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
-                        <popUpButtonCell key="cell" type="push" title="Disabled" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" borderStyle="borderAndBezel" imageScaling="proportionallyDown" inset="2" selectedItem="lxQ-4n-kEv" id="lvb-QF-0Ht">
+                        <popUpButtonCell key="cell" type="push" title="Disabled" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" state="on" borderStyle="borderAndBezel" imageScaling="proportionallyDown" inset="2" selectedItem="lxQ-4n-kEv" id="lvb-QF-0Ht">
                             <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
                             <font key="font" metaFont="menu"/>
                             <menu key="menu" id="lbS-Lw-kQX">
                                 <items>
-                                    <menuItem title="Disabled" id="lxQ-4n-kEv">
+                                    <menuItem title="Disabled" state="on" id="lxQ-4n-kEv">
                                         <modifierMask key="keyEquivalentModifierMask"/>
                                     </menuItem>
-                                    <menuItem title="10 Seconds" state="on" tag="10" id="bPU-vT-d5z"/>
+                                    <menuItem title="10 Seconds" tag="10" id="bPU-vT-d5z"/>
                                     <menuItem title="30 Seconds" tag="30" id="aR8-IU-fFh"/>
                                     <menuItem title="1 Minute" tag="60" id="E0R-mf-Hdl"/>
                                     <menuItem title="2 Minutes" tag="120" id="zb2-uh-lvj"/>

SDL/gui.c

@@ -350,6 +350,7 @@ struct shader_name {
     {"NearestNeighbor", "Nearest Neighbor"},
     {"Bilinear", "Bilinear"},
     {"SmoothBilinear", "Smooth Bilinear"},
+    {"LCD", "LCD Display"},
     {"Scale2x", "Scale2x"},
     {"Scale4x", "Scale4x"},
     {"AAScale2x", "Anti-aliased Scale2x"},

Shaders/LCD.fsh

@@ -0,0 +1,70 @@
+#define COLOR_LOW 0.8
+#define COLOR_HIGH 1.0
+#define SCANLINE_DEPTH 0.1
+
+vec4 scale(sampler2D image)
+{
+    vec2 texCoord = vec2(gl_FragCoord.x, uResolution.y - gl_FragCoord.y) / uResolution;
+    
+    vec2 pos = fract(texCoord * textureDimensions);
+    vec2 sub_pos = fract(texCoord * textureDimensions * 6);
+    
+    vec4 center = texture(image, texCoord);
+    vec4 left = texture(image, texCoord - vec2(1.0 / textureDimensions.x, 0));
+    vec4 right = texture(image, texCoord + vec2(1.0 / textureDimensions.x, 0));
+    
+    if (pos.y < 1.0 / 6.0) {
+        center = mix(center, texture(image, texCoord + vec2(0, -1.0 / textureDimensions.y)), 0.5 - sub_pos.y / 2.0);
+        left =   mix(left,   texture(image, texCoord + vec2(-1.0 / textureDimensions.x, -1.0 / textureDimensions.y)), 0.5 - sub_pos.y / 2.0);
+        right =  mix(right,  texture(image, texCoord + vec2( 1.0 / textureDimensions.x, -1.0 / textureDimensions.y)), 0.5 - sub_pos.y / 2.0);
+        center *= sub_pos.y * SCANLINE_DEPTH + (1 - SCANLINE_DEPTH);
+        left *= sub_pos.y * SCANLINE_DEPTH + (1 - SCANLINE_DEPTH);
+        right *= sub_pos.y * SCANLINE_DEPTH + (1 - SCANLINE_DEPTH);
+    }
+    else if (pos.y > 5.0 / 6.0) {
+        center = mix(center, texture(image, texCoord + vec2(0, 1.0 / textureDimensions.y)), sub_pos.y / 2.0);
+        left =   mix(left,   texture(image, texCoord + vec2(-1.0 / textureDimensions.x, 1.0 / textureDimensions.y)), sub_pos.y / 2.0);
+        right =  mix(right,  texture(image, texCoord + vec2( 1.0 / textureDimensions.x, 1.0 / textureDimensions.y)), sub_pos.y / 2.0);
+        center *= (1.0 - sub_pos.y) * SCANLINE_DEPTH + (1 - SCANLINE_DEPTH);
+        left *= (1.0 - sub_pos.y) * SCANLINE_DEPTH + (1 - SCANLINE_DEPTH);
+        right *= (1.0 - sub_pos.y) * SCANLINE_DEPTH + (1 - SCANLINE_DEPTH);
+    }
+    
+    
+    vec4 midleft = mix(left, center, 0.5);
+    vec4 midright = mix(right, center, 0.5);
+    
+    vec4 ret;
+    if (pos.x < 1.0 / 6.0) {
+        ret = mix(vec4(COLOR_HIGH * center.r, COLOR_LOW * center.g, COLOR_HIGH * left.b, 1),
+                  vec4(COLOR_HIGH * center.r, COLOR_LOW * center.g, COLOR_LOW  * left.b, 1),
+                  sub_pos.x);
+    }
+    else if (pos.x < 2.0 / 6.0) {
+        ret = mix(vec4(COLOR_HIGH * center.r, COLOR_LOW  * center.g, COLOR_LOW * left.b, 1),
+                  vec4(COLOR_HIGH * center.r, COLOR_HIGH * center.g, COLOR_LOW * midleft.b, 1),
+                  sub_pos.x);
+    }
+    else if (pos.x < 3.0 / 6.0) {
+        ret = mix(vec4(COLOR_HIGH * center.r  , COLOR_HIGH * center.g, COLOR_LOW * midleft.b, 1),
+                  vec4(COLOR_LOW  * midright.r, COLOR_HIGH * center.g, COLOR_LOW * center.b, 1),
+                  sub_pos.x);
+    }
+    else if (pos.x < 4.0 / 6.0) {
+        ret = mix(vec4(COLOR_LOW * midright.r, COLOR_HIGH * center.g , COLOR_LOW  * center.b, 1),
+                  vec4(COLOR_LOW * right.r   , COLOR_HIGH  * center.g, COLOR_HIGH * center.b, 1),
+                  sub_pos.x);
+    }
+    else if (pos.x < 5.0 / 6.0) {
+        ret = mix(vec4(COLOR_LOW * right.r, COLOR_HIGH * center.g  , COLOR_HIGH * center.b, 1),
+                  vec4(COLOR_LOW * right.r, COLOR_LOW  * midright.g, COLOR_HIGH * center.b, 1),
+                  sub_pos.x);
+    }
+    else {
+        ret = mix(vec4(COLOR_LOW  * right.r, COLOR_LOW * midright.g, COLOR_HIGH * center.b, 1),
+                  vec4(COLOR_HIGH * right.r, COLOR_LOW * right.g  ,  COLOR_HIGH * center.b, 1),
+                  sub_pos.x);
+    }
+    
+    return ret;
+}