Wallpaper: cool fade in transition via shader

Shaders/frag/mix_images.frag

@@ -0,0 +1,22 @@
+#version 450
+
+layout(location = 0) in vec2 qt_TexCoord0;
+layout(location = 0) out vec4 fragColor;
+layout(binding = 1) uniform sampler2D source1;
+layout(binding = 2) uniform sampler2D source2;
+layout(std140, binding = 0) uniform buf {
+    mat4 qt_Matrix;
+    float qt_Opacity;
+    float fade;
+};
+
+void main() {
+    vec4 color1 = texture(source1, qt_TexCoord0);
+    vec4 color2 = texture(source2, qt_TexCoord0);
+    
+    // Smooth cross-fade using smoothstep for better visual quality
+    float smoothFade = smoothstep(0.0, 1.0, fade);
+    
+    // Mix the two textures based on fade value
+    fragColor = mix(color1, color2, smoothFade) * qt_Opacity;
+}