Text + MXL logo pattern

2026-09-13 16:33:50 +03:00
parent 94ff41a124
commit 97dec92b8b
15 changed files with 999 additions and 23 deletions
@@ -0,0 +1,156 @@
+package generator
+
+import (
+	"encoding/binary"
+	"path/filepath"
+	"testing"
+
+	"golang.org/x/image/font"
+)
+
+func testFace(t *testing.T, size float64) font.Face {
+	t.Helper()
+	face, err := LoadFace(filepath.Join("..", "..", "assets", "fonts",
+		"JetBrainsMonoNLNerdFontMono-Regular.ttf"), size)
+	if err != nil {
+		t.Fatalf("LoadFace: %v", err)
+	}
+	t.Cleanup(func() { face.Close() })
+	return face
+}
+
+func TestNewTextOverlay(t *testing.T) {
+	const frameW, frameH = 1920, 1080
+
+	o, err := NewTextOverlay("AB", frameW, frameH, testFace(t, 48))
+	if err != nil {
+		t.Fatalf("NewTextOverlay: %v", err)
+	}
+	if o.w%6 != 0 {
+		t.Fatalf("w=%d not a multiple of 6", o.w)
+	}
+	if o.x%6 != 0 {
+		t.Fatalf("x=%d not a multiple of 6", o.x)
+	}
+	if center := o.x + o.w/2; center < frameW/2-3 || center > frameW/2+3 {
+		t.Fatalf("box center %d not near frame center %d", center, frameW/2)
+	}
+	if o.y != 48 {
+		t.Fatalf("y=%d, want 48", o.y)
+	}
+	if o.blocks == nil || len(o.blocks) != o.h*(o.w/6)*16 {
+		t.Fatalf("pre-packed tile has wrong size")
+	}
+	if o.cov[2*o.w+2] != 0 {
+		t.Fatalf("padding pixel (2,2) covered: %d", o.cov[2*o.w+2])
+	}
+	nonzero, full := 0, 0
+	for _, c := range o.cov {
+		if c > 0 {
+			nonzero++
+		}
+		if c == 255 {
+			full++
+		}
+	}
+	if nonzero < 100 {
+		t.Fatalf("too few covered pixels: %d", nonzero)
+	}
+	if full == 0 {
+		t.Fatalf("no fully covered (255) pixels")
+	}
+
+	// Text without descenders ("AB") must leave the bottom quarter empty;
+	// text with a descender ("Ag") must have coverage there.
+	for _, tc := range []struct {
+		text    string
+		wantAny bool
+	}{
+		{"AB", false},
+		{"Ag", true},
+	} {
+		o, err := NewTextOverlay(tc.text, frameW, frameH, testFace(t, 48))
+		if err != nil {
+			t.Fatalf("NewTextOverlay(%q): %v", tc.text, err)
+		}
+		any := false
+		for row := o.h * 3 / 4; row < o.h; row++ {
+			for col := 0; col < o.w; col++ {
+				if o.cov[row*o.w+col] > 0 {
+					any = true
+				}
+			}
+		}
+		if any != tc.wantAny {
+			t.Fatalf("%q: coverage in bottom quarter = %v, want %v", tc.text, any, tc.wantAny)
+		}
+	}
+}
+
+func TestTextOverlayApplyV210(t *testing.T) {
+	const frameW, frameH = 1920, 1080
+	o, err := NewTextOverlay("MXL", frameW, frameH, testFace(t, 48))
+	if err != nil {
+		t.Fatalf("NewTextOverlay: %v", err)
+	}
+
+	frame := make([]byte, frameW*frameH*8/3)
+	for i := range frame {
+		frame[i] = 0x5A // marker: untouched regions must survive
+	}
+	if err := o.ApplyV210(frame); err != nil {
+		t.Fatalf("ApplyV210: %v", err)
+	}
+
+	sample := func(x, y int) (yc, cb, cr uint32) {
+		p := y*frameW + x
+		off := (p / 6) * 16
+		w0 := binary.LittleEndian.Uint32(frame[off:])
+		w1 := binary.LittleEndian.Uint32(frame[off+4:])
+		w2 := binary.LittleEndian.Uint32(frame[off+8:])
+		w3 := binary.LittleEndian.Uint32(frame[off+12:])
+		switch p % 6 {
+		case 0:
+			return (w0 >> 10) & 0x3FF, w0 & 0x3FF, (w0 >> 20) & 0x3FF
+		case 1:
+			return w1 & 0x3FF, w0 & 0x3FF, (w0 >> 20) & 0x3FF
+		case 2:
+			return (w1 >> 20) & 0x3FF, (w1 >> 10) & 0x3FF, w2 & 0x3FF
+		case 3:
+			return (w2 >> 10) & 0x3FF, (w1 >> 10) & 0x3FF, w2 & 0x3FF
+		case 4:
+			return w3 & 0x3FF, (w2 >> 20) & 0x3FF, (w3 >> 10) & 0x3FF
+		default:
+			return (w3 >> 20) & 0x3FF, (w2 >> 20) & 0x3FF, (w3 >> 10) & 0x3FF
+		}
+	}
+
+	// Every box pixel: Y from coverage, neutral chroma at even columns.
+	for row := 0; row < o.h; row++ {
+		for col := 0; col < o.w; col++ {
+			wantY := uint32(64 + (int(o.cov[row*o.w+col])*876+127)/255)
+			yc, cb, cr := sample(o.x+col, o.y+row)
+			if yc != wantY {
+				t.Fatalf("box pixel (%d,%d): Y=%d, want %d", o.x+col, o.y+row, yc, wantY)
+			}
+			if (o.x+col)%2 == 0 && (cb != 512 || cr != 512) {
+				t.Fatalf("box pixel (%d,%d): Cb=%d Cr=%d, want 512/512", o.x+col, o.y+row, cb, cr)
+			}
+		}
+	}
+
+	// Blocks just outside the box (right edge and below) must be untouched.
+	for _, p := range [][2]int{
+		{o.x + o.w, o.y},       // right of box, block-aligned
+		{o.x, o.y + o.h},       // below box
+		{o.x + o.w, o.y + o.h}, // corner
+		{100, 1000},            // far away
+	} {
+		off := ((p[1]*frameW + p[0]) / 6) * 16
+		for i := 0; i < 16; i++ {
+			if frame[off+i] != 0x5A {
+				t.Fatalf("block at (%d,%d) modified outside the box", p[0], p[1])
+			}
+		}
+	}
+}