1 files changed, 26 insertions, 0 deletions
diff --git a/shaders/bloom-up.frag.glsl b/shaders/bloom-up.frag.glsl
new file mode 100644
index 00000000..368076ed
--- /dev/null
+++ b/shaders/bloom-up.frag.glsl
@@ -0,0 +1,26 @@
+#version 450
+
+// Bloom, up (docs/effects.md G4): one step of a dual Kawase filter back up,
+// a tent of eight points over the smaller level. Float target.
+
+layout(set = 2, binding = 0) uniform sampler2D source;
+layout(std140, set = 3, binding = 0) uniform BloomStep {
+    vec4 texels;
+    vec4 pass;
+} u;
+
+layout(location = 0) out vec4 o_col;
+
+void main() {
+    vec2 uv = gl_FragCoord.xy * u.texels.zw;
+    vec2 h = 0.5 * u.texels.xy;
+    vec3 sum = texture(source, uv + vec2(-2.0 * h.x, 0.0)).rgb;
+    sum += texture(source, uv + vec2(-h.x, h.y)).rgb * 2.0;
+    sum += texture(source, uv + vec2(0.0, 2.0 * h.y)).rgb;
+    sum += texture(source, uv + vec2(h.x, h.y)).rgb * 2.0;
+    sum += texture(source, uv + vec2(2.0 * h.x, 0.0)).rgb;
+    sum += texture(source, uv + vec2(h.x, -h.y)).rgb * 2.0;
+    sum += texture(source, uv + vec2(0.0, -2.0 * h.y)).rgb;
+    sum += texture(source, uv + vec2(-h.x, -h.y)).rgb * 2.0;
+    o_col = vec4(sum / 12.0, 1.0);
+}