Modernize gfx

.github/workflows/test.yml

@@ -10,7 +10,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: ['1.24.x', '1.23.x']
+        go-version: ['1.26.x', '1.25.x']
         os: [ubuntu-latest]
     runs-on: ${{ matrix.os }}
     steps:

LICENSE

@@ -1,4 +1,4 @@
-Copyright (c) 2019-2025 Peter Hellberg - https://c7.se
+Copyright (c) 2019-2026 Peter Hellberg - https://c7.se
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the

README.md

@@ -61,11 +61,11 @@ var edg32 = gfx.PaletteEDG32
 func main() {
 	m := gfx.NewNRGBA(gfx.IR(0, 0, 1024, 256))
 	p := gfx.Polygon{
-		{80, 40},
-		{440, 60},
-		{700, 200},
-		{250, 230},
-		{310, 140},
+		gfx.V(80, 40),
+		gfx.V(440, 60),
+		gfx.V(700, 200),
+		gfx.V(250, 230),
+		gfx.V(310, 140),
 	}
 
 	p.EachPixel(m, func(x, y int) {
@@ -141,7 +141,7 @@ func main() {
 	m := gfx.NewImage(1024, 256, c(5))
 
 	gfx.EachPixel(m.Bounds(), func(x, y int) {
-		sd := gfx.SignedDistance{gfx.IV(x, y)}
+		sd := gfx.SignedDistance{Vec: gfx.IV(x, y)}
 
 		if d := sd.OpRepeat(gfx.V(128, 128), func(sd gfx.SignedDistance) float64 {
 			return sd.OpSubtraction(sd.Circle(50), sd.Line(gfx.V(0, 0), gfx.V(64, 64)))
@@ -193,10 +193,10 @@ func main() {
 		m  = gfx.NewImage(w, h)
 	)
 
-	for py := 0; py < h; py++ {
+	for py := range h {
 		x := p0.X
 
-		for px := 0; px < w; px++ {
+		for px := range w {
 			cc := p.CmplxPhaseAt(gfx.CmplxCos(gfx.CmplxSin(0.42 / complex(y*x, x*x))))
 
 			m.Set(px, py, cc)
@@ -242,7 +242,7 @@ func main() {
 	}
 
 	for i := 0; i < len(p)-4; i++ {
-		t := gfx.NewTile(p[i:i+4], 8, fireflower)
+		t := gfx.NewTile(p[i:i+5], 8, fireflower)
 
 		a.AddPalettedImage(gfx.NewScaledPalettedImage(t, 20))
 	}
@@ -369,11 +369,11 @@ func main() {
 	c := gfx.V(128, 128)
 
 	p := gfx.Polygon{
-		{50, 50},
-		{50, 206},
-		{128, 96},
-		{206, 206},
-		{206, 50},
+		gfx.V(50, 50),
+		gfx.V(50, 206),
+		gfx.V(128, 96),
+		gfx.V(206, 206),
+		gfx.V(206, 50),
 	}
 
 	for d := 0.0; d < 360; d += 2 {
@@ -411,7 +411,20 @@ The `gfx.Error` type is a string that implements the `error` interface.
 
 ## HTTP
 
-You can use `gfx.GetPNG` to download and decode a PNG given an URL.
+HTTP helpers live in the `gfxhttp` subpackage so that importers of `gfx`
+who do not need them are not forced to pull in `net/http` (and its
+transitive `crypto/tls`, `crypto/x509`, `net`, etc.).
+
+```go
+import "github.com/peterhellberg/gfx/gfxhttp"
+
+img, err := gfxhttp.GetPNG(ctx, "https://example.com/sprite.png")
+```
+
+`gfxhttp.NewClient` accepts options like `WithUserAgent`, `WithTimeout`,
+`WithHTTPClient` and `WithHeader`. Non-2xx responses are returned as
+`*gfxhttp.StatusError`. Map tile servers are available through
+`gfxhttp.TileServer`.
 
 ## Log
 
@@ -421,9 +434,13 @@ when experimenting with graphical effects, so I've included `gfx.Log`,
 
 ## Math
 
-I have included a few functions that call functions in the `math` package.
+I have included a few functions that call functions in the `math` package
+(`gfx.MathMin`, `gfx.MathMax`, `gfx.MathAbs`, `gfx.MathSqrt`, …) so that you
+don't have to import `math` yourself.
 
-There is also `gfx.Sign`, `gfx.Clamp` and `gfx.Lerp` functions for `float64`.
+`gfx.Sign`, `gfx.Clamp` and `gfx.Lerp` are generic: `gfx.Sign` and `gfx.Lerp`
+work on any numeric type (the `gfx.Numeric`/`gfx.Signed` constraints) and
+`gfx.Clamp` works on any `cmp.Ordered` type.
 
 ## Cmplx
 
@@ -581,7 +598,7 @@ func main() {
 
 ## License (MIT)
 
-Copyright (c) 2019-2025 [Peter Hellberg](https://c7.se)
+Copyright (c) 2019-2026 [Peter Hellberg](https://c7.se)
 
 > Permission is hereby granted, free of charge, to any person obtaining
 > a copy of this software and associated documentation files (the

animation.go

@@ -1,6 +1,3 @@
-//go:build !tinygo
-// +build !tinygo
-
 package gfx
 
 import (

base64.go

@@ -1,6 +1,3 @@
-//go:build !tinygo
-// +build !tinygo
-
 package gfx
 
 import (

batch.go

@@ -1,6 +1,3 @@
-//go:build !tinygo
-// +build !tinygo
-
 package gfx
 
 import "image/color"

block.go

@@ -1,6 +1,3 @@
-//go:build !tinygo
-// +build !tinygo
-
 package gfx
 
 import (
@@ -80,12 +77,12 @@ func (b Block) Triangles(origin Vec3) []Triangle {
 	c, l, m, d := b.Corners(origin), b.Color.Light, b.Color.Medium, b.Color.Dark
 
 	return []Triangle{
-		T(Vx(c.FrontUp, d), Vx(c.LeftDown), Vx(c.LeftUp)),
-		T(Vx(c.FrontUp, d), Vx(c.FrontDown), Vx(c.LeftDown)),
-		T(Vx(c.FrontUp, m), Vx(c.FrontDown), Vx(c.RightDown)),
-		T(Vx(c.FrontUp, m), Vx(c.RightUp), Vx(c.RightDown)),
-		T(Vx(c.FrontUp, l), Vx(c.BackUp), Vx(c.LeftUp)),
-		T(Vx(c.FrontUp, l), Vx(c.BackUp), Vx(c.RightUp)),
+		T(Vx(c.FrontUp, d), Vx(c.LeftDown, d), Vx(c.LeftUp, d)),
+		T(Vx(c.FrontUp, d), Vx(c.FrontDown, d), Vx(c.LeftDown, d)),
+		T(Vx(c.FrontUp, m), Vx(c.FrontDown, m), Vx(c.RightDown, m)),
+		T(Vx(c.FrontUp, m), Vx(c.RightUp, m), Vx(c.RightDown, m)),
+		T(Vx(c.FrontUp, l), Vx(c.BackUp, l), Vx(c.LeftUp, l)),
+		T(Vx(c.FrontUp, l), Vx(c.BackUp, l), Vx(c.RightUp, l)),
 	}
 }
 
@@ -128,14 +125,23 @@ func (b Block) DrawRectangles(dst draw.Image, origin Vec3) {
 func (b Block) DrawBounds(dst draw.Image, origin Vec3) {
 	r := b.Rect(origin)
 
+	// Round Min down and Max up so the rectangle covers every pixel
+	// the float Rect touches — otherwise a fractional right/bottom edge
+	// loses a column or row through int() truncation.
+	minX := int(math.Floor(r.Min.X))
+	minY := int(math.Floor(r.Min.Y))
+	maxX := int(math.Floor(r.Max.X)) + 1
+	maxY := int(math.Floor(r.Max.Y)) + 1
+
 	if r.Area() < 20 {
-		DrawColor(dst, r.Bounds(), b.Color.Medium)
+		DrawColor(dst, IR(minX, minY, maxX, maxY), b.Color.Medium)
 		return
 	}
 
 	rw6 := r.W() / 6
+	topMaxY := int(math.Floor(r.Max.Y-rw6)) + 1
 
-	DrawColor(dst, IR(int(r.Min.X), int(r.Min.Y), int(r.Max.X), int(r.Max.Y-rw6)), b.Color.Light)
+	DrawColor(dst, IR(minX, minY, maxX, topMaxY), b.Color.Light)
 
 	DrawLineBresenham(dst, r.Min, V(r.Max.X, r.Min.Y), b.Color.Medium)
 	DrawLineBresenham(dst, r.Min, V(r.Min.X, r.Max.Y-rw6), b.Color.Dark)

blocks.go

@@ -1,6 +1,3 @@
-//go:build !tinygo
-// +build !tinygo
-
 package gfx
 
 import (

box.go

@@ -1,6 +1,3 @@
-//go:build !tinygo
-// +build !tinygo
-
 package gfx
 
 // Box is a 3D cuboid with a min and max Vec3

cie_lab.go

@@ -1,6 +1,3 @@
-//go:build !tinygo
-// +build !tinygo
-
 package gfx
 
 import "math"

decode.go

@@ -1,6 +1,3 @@
-//go:build !tinygo
-// +build !tinygo
-
 package gfx
 
 import (

draw.go

@@ -33,10 +33,8 @@ func DrawOver(dst draw.Image, r image.Rectangle, src image.Image, sp image.Point
 
 // DrawPalettedImage draws a PalettedImage over a PalettedDrawImage.
 func DrawPalettedImage(dst PalettedDrawImage, r image.Rectangle, src PalettedImage) {
-	w, h, m := r.Dx(), r.Dy(), r.Min
-
-	for x := m.X; x != w; x++ {
-		for y := m.Y; y != h; y++ {
+	for x := r.Min.X; x < r.Max.X; x++ {
+		for y := r.Min.Y; y < r.Max.Y; y++ {
 			if src.AlphaAt(x, y) > 0 {
 				dst.SetColorIndex(x, y, src.ColorIndexAt(x, y))
 			}
@@ -47,10 +45,8 @@ func DrawPalettedImage(dst PalettedDrawImage, r image.Rectangle, src PalettedIma
 // DrawPalettedLayer draws a *Layer over a *Paletted.
 // (slightly faster than using the generic DrawPalettedImage)
 func DrawPalettedLayer(dst *Paletted, r image.Rectangle, src *Layer) {
-	w, h, m := r.Dx(), r.Dy(), r.Min
-
-	for x := m.X; x != w; x++ {
-		for y := m.Y; y != h; y++ {
+	for x := r.Min.X; x < r.Max.X; x++ {
+		for y := r.Min.Y; y < r.Max.Y; y++ {
 			if src.AlphaAt(x, y) > 0 {
 				dst.SetColorIndex(x, y, src.ColorIndexAt(x, y))
 			}
@@ -83,10 +79,12 @@ func DrawTrianglesOver(dst draw.Image, triangles []Triangle) {
 	}
 }
 
-// DrawTrianglesWireframe draws triangles on dst.
+// DrawTrianglesWireframe draws triangles on dst using each triangle's
+// first vertex color.
 func DrawTrianglesWireframe(dst draw.Image, triangles []Triangle) {
 	for _, t := range triangles {
-		t.DrawWireframe(dst, t.Color(V(0, 0)))
+		a, _, _ := t.Colors()
+		t.DrawWireframe(dst, a)
 	}
 }
 
@@ -123,8 +121,8 @@ func DrawCircleFilled(dst draw.Image, u Vec, radius float64, c color.Color) {
 	})
 }
 
-// DrawCicleFast draws a (crude) filled circle.
-func DrawCicleFast(dst draw.Image, u Vec, radius float64, c color.Color) {
+// DrawCircleFast draws a (crude) filled circle.
+func DrawCircleFast(dst draw.Image, u Vec, radius float64, c color.Color) {
 	ir := int(radius)
 	r2 := ir * ir
 	pt := u.Pt()

draw_int.go

@@ -84,8 +84,6 @@ func DrawIntRectangle(dst draw.Image, x, y, w, h int, c color.Color) {
 	DrawIntLine(dst, x, y, x, y+h-1, c)
 	DrawIntLine(dst, x+w-1, y, x+w-1, y+h-1, c)
 	DrawIntLine(dst, x, y+h-1, x+w-1, y+h-1, c)
-
-	return
 }
 
 // DrawIntFilledRectangle draws a filled rectangle given a point, width and height
@@ -97,8 +95,6 @@ func DrawIntFilledRectangle(dst draw.Image, x, y, w, h int, c color.Color) {
 	for i := x; i < x+w; i++ {
 		DrawIntLine(dst, i, y, i, y+h-1, c)
 	}
-
-	return
 }
 
 // DrawIntCircle draws a circle given a point and radius

draw_target.go

@@ -1,6 +1,3 @@
-//go:build !tinygo
-// +build !tinygo
-
 package gfx
 
 import (

draw_test.go

@@ -1,5 +1,4 @@
 //go:build !tinygo
-// +build !tinygo
 
 package gfx
 
@@ -36,6 +35,54 @@ func TestDrawLayerOverPaletted(t *testing.T) {
 	DrawPalettedLayer(dst, dst.Bounds(), src)
 }
 
+func TestDrawPalettedImageNonOriginRect(t *testing.T) {
+	src := NewPaletted(8, 16, PaletteEN4)
+	for i := range src.Pix {
+		src.Pix[i] = 1
+	}
+
+	dst := NewPaletted(8, 16, PaletteEN4)
+	r := IR(2, 4, 6, 10)
+
+	DrawPalettedImage(dst, r, src)
+
+	for y := range 16 {
+		for x := range 8 {
+			inside := x >= r.Min.X && x < r.Max.X && y >= r.Min.Y && y < r.Max.Y
+			got := dst.ColorIndexAt(x, y)
+			want := uint8(0)
+			if inside {
+				want = 1
+			}
+			if got != want {
+				t.Fatalf("dst.ColorIndexAt(%d, %d) = %d, want %d (inside=%v)", x, y, got, want, inside)
+			}
+		}
+	}
+}
+
+func TestDrawPalettedLayerNonOriginRect(t *testing.T) {
+	src := newTestLayer()
+	dst := NewPaletted(16, 12, PaletteEN4)
+	r := IR(4, 4, 12, 8)
+
+	DrawPalettedLayer(dst, r, src)
+
+	for y := range 12 {
+		for x := range 16 {
+			inside := x >= r.Min.X && x < r.Max.X && y >= r.Min.Y && y < r.Max.Y
+			got := dst.ColorIndexAt(x, y)
+			if inside {
+				if want := src.ColorIndexAt(x, y); got != want {
+					t.Fatalf("dst.ColorIndexAt(%d, %d) = %d, want %d (from src)", x, y, got, want)
+				}
+			} else if got != 0 {
+				t.Fatalf("dst.ColorIndexAt(%d, %d) = %d, want 0 (outside r)", x, y, got)
+			}
+		}
+	}
+}
+
 func TestDrawLine(t *testing.T) {
 	dst := NewImage(32, 32)
 
@@ -85,10 +132,10 @@ func TestDrawFilledCircle(t *testing.T) {
 	DrawCircleFilled(dst, V(16, 16), 8, ColorMagenta)
 }
 
-func TestDrawFastFilledCircle(t *testing.T) {
+func TestDrawCircleFast(t *testing.T) {
 	dst := NewImage(32, 32)
 
-	DrawCicleFast(dst, V(16, 16), 8, ColorMagenta)
+	DrawCircleFast(dst, V(16, 16), 8, ColorMagenta)
 }
 
 func TestDrawPointCircle(t *testing.T) {

drawer.go

@@ -1,6 +1,3 @@
-//go:build !tinygo
-// +build !tinygo
-
 package gfx
 
 // Drawer glues all the fundamental interfaces (Target, Triangles, Picture) into a coherent and the

errors.go

@@ -12,6 +12,6 @@ func (e Error) Error() string {
 }
 
 // Errorf constructs a formatted error.
-func Errorf(format string, a ...interface{}) error {
+func Errorf(format string, a ...any) error {
 	return Error(Sprintf(format, a...))
 }