Merge pull request mixxxdj#13256 from m0dB/fix-slipmode-shader

fix slipmode shader for macOS

src/shaders/slipmodeshader.cpp

@@ -4,10 +4,9 @@ using namespace mixxx;
 
 void SlipModeShader::init() {
     QString vertexShaderCode = QStringLiteral(R"--(
-#version 150
 attribute highp vec4 position; // use vec4 here (will be padded) to assign directly to gl_Position
 
-out highp vec4 vposition;
+varying highp vec4 vposition;
 
 void main()
 {
@@ -17,12 +16,11 @@ void main()
 )--");
 
     QString fragmentShaderCode = QStringLiteral(R"--(
-#version 120
 uniform highp vec4 color;
 uniform highp vec2 borders;
 uniform highp vec2 dimension;
 
-in highp vec4 vposition;
+varying highp vec4 vposition;
 
 void main()
 {
@@ -32,21 +30,21 @@ void main()
     float upperBoard = borders.x;
     float lowerBoard = borders.y;
 
-    if (yBorder < 0){
+    if (yBorder < 0.0){
         float borderAlpha = max(
-            0, 
+            0.0, 
             lowerBoard + yBorder
         ) / lowerBoard;
-        gl_FragColor = vec4(color.xyz, mix(0, color.w, borderAlpha));
+        gl_FragColor = vec4(color.xyz, mix(0.0, color.w, borderAlpha));
 
-    } else if( (xBorder > dimension.x - upperBoard && yBorder >= 0) || yBorder > dimension.y - upperBoard)
+    } else if( (xBorder > dimension.x - upperBoard && yBorder >= 0.0) || yBorder > dimension.y - upperBoard)
     {
-        float borderAlpha = max(0, max(
+        float borderAlpha = max(0.0, max(
             yBorder - dimension.y, 
             xBorder - dimension.x) + upperBoard) / upperBoard;
-        gl_FragColor = vec4(mix(vec3(0, 0, 0), color.rgb, min(color.w, borderAlpha)), 1);
+        gl_FragColor = vec4(mix(vec3(0.0, 0.0, 0.0), color.rgb, min(color.w, borderAlpha)), 1.0);
     } else {
-        gl_FragColor = vec4(0, 0, 0, 1);
+        gl_FragColor = vec4(0.0, 0.0, 0.0, 1.0);
     }
 }
 )--");