Add kawase blur (#120)

Co-authored-by: Erik Reider <[email protected]>
Co-authored-by: Will McKinnon <[email protected]>

1 files changed, 22 insertions, 0 deletions

diff --git a/sway/desktop/fx_renderer/shaders/blur2.frag b/sway/desktop/fx_renderer/shaders/blur2.frag
new file mode 100644
index 00000000..3755a294
--- /dev/null
+++ b/sway/desktop/fx_renderer/shaders/blur2.frag
@@ -0,0 +1,22 @@
+precision mediump float;
+varying mediump vec2 v_texcoord;
+uniform sampler2D tex;
+
+uniform float radius;
+uniform vec2 halfpixel;
+
+void main() {
+    vec2 uv = v_texcoord / 2.0;
+
+    vec4 sum = texture2D(tex, uv + vec2(-halfpixel.x * 2.0, 0.0) * radius);
+
+    sum += texture2D(tex, uv + vec2(-halfpixel.x, halfpixel.y) * radius) * 2.0;
+    sum += texture2D(tex, uv + vec2(0.0, halfpixel.y * 2.0) * radius);
+    sum += texture2D(tex, uv + vec2(halfpixel.x, halfpixel.y) * radius) * 2.0;
+    sum += texture2D(tex, uv + vec2(halfpixel.x * 2.0, 0.0) * radius);
+    sum += texture2D(tex, uv + vec2(halfpixel.x, -halfpixel.y) * radius) * 2.0;
+    sum += texture2D(tex, uv + vec2(0.0, -halfpixel.y * 2.0) * radius);
+    sum += texture2D(tex, uv + vec2(-halfpixel.x, -halfpixel.y) * radius) * 2.0;
+
+    gl_FragColor = sum / 12.0;
+}