From f5df9506ce1a0d13bfafd207bf0ef126339dbabd Mon Sep 17 00:00:00 2001
From: Dmitry Sergeev <mrjitten@protonmail.com>
Date: Thu, 17 Sep 2026 22:59:42 +0300
Subject: [PATCH] static pattern frame cache

---
 internal/video/pattern.go      |  6 +++++
 internal/video/pattern_test.go |  9 +++++++-
 internal/video/runner.go       | 40 ++++++++++++++++++++++++++++------
 3 files changed, 47 insertions(+), 8 deletions(-)

diff --git a/internal/video/pattern.go b/internal/video/pattern.go
index d63bbe1..49d3951 100644
--- a/internal/video/pattern.go
+++ b/internal/video/pattern.go
@@ -15,6 +15,7 @@ type PatternInfo struct {
 type pattern struct {
 	PatternInfo
 	kernelSource string
+	dynamic      bool
 }
 
 var patterns = map[string]pattern{
@@ -25,6 +26,7 @@ var patterns = map[string]pattern{
 	"ebu75-move": {
 		PatternInfo:  PatternInfo{Name: "ebu75-move", Description: "EBU 75% Color Bar Signal with moving square"},
 		kernelSource: mustReadKernel("dynamic/ebu75.wgsl"),
+		dynamic:      true,
 	},
 	"ebu100": {
 		PatternInfo:  PatternInfo{Name: "ebu100", Description: "EBU 100% Color Bar Signal"},
@@ -33,6 +35,7 @@ var patterns = map[string]pattern{
 	"ebu100-move": {
 		PatternInfo:  PatternInfo{Name: "ebu100-move", Description: "EBU 100% Color Bar Signal with moving square"},
 		kernelSource: mustReadKernel("dynamic/ebu100.wgsl"),
+		dynamic:      true,
 	},
 	"smpte": {
 		PatternInfo:  PatternInfo{Name: "smpte", Description: "SMPTE RP-219 Color Bar Signal"},
@@ -41,6 +44,7 @@ var patterns = map[string]pattern{
 	"smpte-move": {
 		PatternInfo:  PatternInfo{Name: "smpte-move", Description: "SMPTE RP-219 Color Bar Signal with moving square"},
 		kernelSource: mustReadKernel("dynamic/smpteBars.wgsl"),
+		dynamic:      true,
 	},
 	"gray-bars": {
 		PatternInfo:  PatternInfo{Name: "gray-bars", Description: "13-step grayscale bars (Y 64..940)"},
@@ -49,6 +53,7 @@ var patterns = map[string]pattern{
 	"gray-bars-move": {
 		PatternInfo:  PatternInfo{Name: "gray-bars-move", Description: "13-step grayscale bars (Y 64..940) with moving square"},
 		kernelSource: mustReadKernel("dynamic/yBars.wgsl"),
+		dynamic:      true,
 	},
 	"gray-ramp": {
 		PatternInfo:  PatternInfo{Name: "gray-ramp", Description: "Y gradient (black -> 100% white)"},
@@ -57,6 +62,7 @@ var patterns = map[string]pattern{
 	"gray-ramp-move": {
 		PatternInfo:  PatternInfo{Name: "gray-ramp-move", Description: "Y gradient with moving square"},
 		kernelSource: mustReadKernel("dynamic/yRamp.wgsl"),
+		dynamic:      true,
 	},
 }
 
diff --git a/internal/video/pattern_test.go b/internal/video/pattern_test.go
index 9b738da..55f3b06 100644
--- a/internal/video/pattern_test.go
+++ b/internal/video/pattern_test.go
@@ -1,6 +1,9 @@
 package video
 
-import "testing"
+import (
+	"strings"
+	"testing"
+)
 
 func TestPatterns(t *testing.T) {
 	got := Patterns()
@@ -43,5 +46,9 @@ func TestPatternRegistryKeysMatchNames(t *testing.T) {
 		if pattern.kernelSource == "" {
 			t.Errorf("pattern %q has empty kernel source", name)
 		}
+		wantDynamic := strings.HasSuffix(name, "-move")
+		if pattern.dynamic != wantDynamic {
+			t.Errorf("pattern %q dynamic = %t, want %t", name, pattern.dynamic, wantDynamic)
+		}
 	}
 }
diff --git a/internal/video/runner.go b/internal/video/runner.go
index 5df83f0..9355257 100644
--- a/internal/video/runner.go
+++ b/internal/video/runner.go
@@ -35,6 +35,21 @@ func Run(ctx context.Context, inst *mxl.Instance, cfg Config) (runErr error) {
 		return err
 	}
 
+	var staticFrame []byte
+	if !pattern.dynamic {
+		frameSize := int(cfg.Width()*cfg.Height()) * 8 / 3
+		staticFrame = make([]byte, frameSize)
+
+		if err := gen.GenerateFrame(staticFrame, 0); err != nil {
+			return fmt.Errorf("generate static frame: %w", err)
+		}
+		if overlay != nil {
+			if err := overlay.ApplyV210(staticFrame); err != nil {
+				return fmt.Errorf("apply text overlay to static frame: %w", err)
+			}
+		}
+	}
+
 	flowJSON, err := json.Marshal(cfg.Definition)
 	if err != nil {
 		return fmt.Errorf("marshal video flow definition: %w", err)
@@ -70,13 +85,25 @@ func Run(ctx context.Context, inst *mxl.Instance, cfg Config) (runErr error) {
 		if err != nil {
 			return fmt.Errorf("open video grain %d: %w", idx, err)
 		}
-		if err := gen.GenerateFrame(grain.Payload, int(tick)); err != nil {
-			return cancelGrain(grain, fmt.Errorf("generate frame for grain %d: %w", idx, err))
-		}
-		if overlay != nil {
-			if err := overlay.ApplyV210(grain.Payload); err != nil {
-				return cancelGrain(grain, fmt.Errorf("apply text overlay to grain %d: %w", idx, err))
+		if staticFrame != nil {
+			if len(grain.Payload) != len(staticFrame) {
+				return cancelGrain(grain, fmt.Errorf(
+					"video grain payload size %d, expected %d",
+					len(grain.Payload),
+					len(staticFrame),
+				))
 			}
+			copy(grain.Payload, staticFrame)
+		} else {
+			if err := gen.GenerateFrame(grain.Payload, int(tick)); err != nil {
+				return cancelGrain(grain, fmt.Errorf("generate frame for grain %d: %w", idx, err))
+			}
+			if overlay != nil {
+				if err := overlay.ApplyV210(grain.Payload); err != nil {
+					return cancelGrain(grain, fmt.Errorf("apply text overlay to grain %d: %w", idx, err))
+				}
+			}
+			tick++
 		}
 		if err := grain.Commit(grain.TotalSlices, 0); err != nil {
 			return fmt.Errorf("commit video grain %d: %w", idx, err)
@@ -84,7 +111,6 @@ func Run(ctx context.Context, inst *mxl.Instance, cfg Config) (runErr error) {
 
 		grainsWritten++
 		idx++
-		tick++
 		if grainsWritten%100 == 0 {
 			log.Printf("video grains written=%d, next index=%d", grainsWritten, idx)
 		}