ebiten: Allow SubImage at DrawRectShader

image.go

@@ -274,26 +274,23 @@ func (i *Image) DrawImage(img *Image, options *DrawImageOptions) error {
 	vs := graphics.QuadVertices(sx0, sy0, sx1, sy1, a, b, c, d, tx, ty, 1, 1, 1, 1, filter == driver.FilterScreen)
 	is := graphics.QuadIndices()
 
-	var sr driver.Region
-	// Pass the source region only when the shader is used, since this affects the condition of merging graphics
-	// commands (#1293).
-	if options.Shader != nil {
-		sr = driver.Region{
-			X:      float32(bounds.Min.X),
-			Y:      float32(bounds.Min.Y),
-			Width:  float32(bounds.Dx()),
-			Height: float32(bounds.Dy()),
-		}
-	}
-
 	srcs := [graphics.ShaderImageNum]*mipmap.Mipmap{img.mipmap}
 	if options.Shader == nil {
-		i.mipmap.DrawTriangles(srcs, vs, is, options.ColorM.impl, mode, filter, driver.AddressUnsafe, sr, nil, nil, canSkipMipmap(options.GeoM, filter))
+		i.mipmap.DrawTriangles(srcs, vs, is, options.ColorM.impl, mode, filter, driver.AddressUnsafe, driver.Region{}, [graphics.ShaderImageNum - 1][2]float32{}, nil, nil, canSkipMipmap(options.GeoM, filter))
 		return nil
 	}
 
+	// Pass the source region only when the shader is used, since this affects the condition of merging graphics
+	// commands (#1293).
+	sr := driver.Region{
+		X:      float32(bounds.Min.X),
+		Y:      float32(bounds.Min.Y),
+		Width:  float32(bounds.Dx()),
+		Height: float32(bounds.Dy()),
+	}
+
 	us := options.Shader.convertUniforms(options.Uniforms)
-	i.mipmap.DrawTriangles(srcs, vs, is, nil, mode, filter, driver.AddressUnsafe, sr, options.Shader.shader, us, canSkipMipmap(options.GeoM, filter))
+	i.mipmap.DrawTriangles(srcs, vs, is, nil, mode, filter, driver.AddressUnsafe, sr, [graphics.ShaderImageNum - 1][2]float32{}, options.Shader.shader, us, canSkipMipmap(options.GeoM, filter))
 	return nil
 }
 
@@ -489,12 +486,12 @@ func (i *Image) DrawTriangles(vertices []Vertex, indices []uint16, img *Image, o
 	}
 
 	if options.Shader == nil {
-		i.mipmap.DrawTriangles(srcs, vs, is, options.ColorM.impl, mode, filter, driver.Address(options.Address), sr, nil, nil, false)
+		i.mipmap.DrawTriangles(srcs, vs, is, options.ColorM.impl, mode, filter, driver.Address(options.Address), sr, [graphics.ShaderImageNum - 1][2]float32{}, nil, nil, false)
 		return
 	}
 
 	us := options.Shader.convertUniforms(options.Uniforms)
-	i.mipmap.DrawTriangles(srcs, vs, is, nil, mode, driver.FilterNearest, driver.AddressUnsafe, sr, options.Shader.shader, us, false)
+	i.mipmap.DrawTriangles(srcs, vs, is, nil, mode, driver.FilterNearest, driver.AddressUnsafe, sr, [graphics.ShaderImageNum - 1][2]float32{}, options.Shader.shader, us, false)
 }
 
 // DrawRectShaderOptions represents options for DrawRectShader
@@ -557,18 +554,21 @@ func (i *Image) DrawRectShader(width, height int, shader *Shader, options *DrawR
 		if img.isDisposed() {
 			panic("ebiten: the given image to DrawRectShader must not be disposed")
 		}
-		if img.isSubImage() {
-			// TODO: Implement this.
-			panic("ebiten: rendering a sub-image is not implemented (DrawRectShader)")
-		}
 		if w, h := img.Size(); width != w || height != h {
 			panic("ebiten: all the source images must be the same size with the rectangle")
 		}
 		imgs[i] = img.mipmap
 	}
 
+	sx, sy := float32(0), float32(0)
+	if options.Images[0] != nil {
+		b := options.Images[0].Bounds()
+		sx = float32(b.Min.X)
+		sy = float32(b.Min.Y)
+	}
+
 	a, b, c, d, tx, ty := options.GeoM.elements32()
-	vs := graphics.QuadVertices(0, 0, float32(width), float32(height), a, b, c, d, tx, ty, 1, 1, 1, 1, false)
+	vs := graphics.QuadVertices(sx, sy, sx+float32(width), sy+float32(height), a, b, c, d, tx, ty, 1, 1, 1, 1, false)
 	is := graphics.QuadIndices()
 
 	var sr driver.Region
@@ -582,8 +582,18 @@ func (i *Image) DrawRectShader(width, height int, shader *Shader, options *DrawR
 		}
 	}
 
+	var offsets [graphics.ShaderImageNum - 1][2]float32
+	for i, img := range options.Images[1:] {
+		if img == nil {
+			continue
+		}
+		b := img.Bounds()
+		offsets[i][0] = -sx + float32(b.Min.X)
+		offsets[i][1] = -sy + float32(b.Min.Y)
+	}
+
 	us := shader.convertUniforms(options.Uniforms)
-	i.mipmap.DrawTriangles(imgs, vs, is, nil, mode, driver.FilterNearest, driver.AddressUnsafe, sr, shader.shader, us, canSkipMipmap(options.GeoM, driver.FilterNearest))
+	i.mipmap.DrawTriangles(imgs, vs, is, nil, mode, driver.FilterNearest, driver.AddressUnsafe, sr, offsets, shader.shader, us, canSkipMipmap(options.GeoM, driver.FilterNearest))
 }
 
 // SubImage returns an image representing the portion of the image p visible through r.

internal/buffered/image.go

@@ -248,7 +248,7 @@ func (i *Image) replacePendingPixels(pix []byte, x, y, width, height int) {
 // DrawTriangles draws the src image with the given vertices.
 //
 // Copying vertices and indices is the caller's responsibility.
-func (i *Image) DrawTriangles(srcs [graphics.ShaderImageNum]*Image, vertices []float32, indices []uint16, colorm *affine.ColorM, mode driver.CompositeMode, filter driver.Filter, address driver.Address, sourceRegion driver.Region, shader *Shader, uniforms []interface{}) {
+func (i *Image) DrawTriangles(srcs [graphics.ShaderImageNum]*Image, vertices []float32, indices []uint16, colorm *affine.ColorM, mode driver.CompositeMode, filter driver.Filter, address driver.Address, sourceRegion driver.Region, subimageOffsets [graphics.ShaderImageNum - 1][2]float32, shader *Shader, uniforms []interface{}) {
 	for _, src := range srcs {
 		if i == src {
 			panic("buffered: Image.DrawTriangles: source images must be different from the receiver")
@@ -258,7 +258,7 @@ func (i *Image) DrawTriangles(srcs [graphics.ShaderImageNum]*Image, vertices []f
 	if maybeCanAddDelayedCommand() {
 		if tryAddDelayedCommand(func() error {
 			// Arguments are not copied. Copying is the caller's responsibility.
-			i.DrawTriangles(srcs, vertices, indices, colorm, mode, filter, address, sourceRegion, shader, uniforms)
+			i.DrawTriangles(srcs, vertices, indices, colorm, mode, filter, address, sourceRegion, subimageOffsets, shader, uniforms)
 			return nil
 		}) {
 			return
@@ -286,7 +286,7 @@ func (i *Image) DrawTriangles(srcs [graphics.ShaderImageNum]*Image, vertices []f
 		imgs[i] = img.img
 	}
 
-	i.img.DrawTriangles(imgs, vertices, indices, colorm, mode, filter, address, sourceRegion, s, uniforms)
+	i.img.DrawTriangles(imgs, vertices, indices, colorm, mode, filter, address, sourceRegion, subimageOffsets, s, uniforms)
 	i.invalidatePendingPixels()
 }
 

internal/mipmap/mipmap.go

@@ -97,7 +97,7 @@ func (m *Mipmap) Pixels(x, y, width, height int) ([]byte, error) {
 	return m.orig.Pixels(x, y, width, height)
 }
 
-func (m *Mipmap) DrawTriangles(srcs [graphics.ShaderImageNum]*Mipmap, vertices []float32, indices []uint16, colorm *affine.ColorM, mode driver.CompositeMode, filter driver.Filter, address driver.Address, sourceRegion driver.Region, shader *Shader, uniforms []interface{}, canSkipMipmap bool) {
+func (m *Mipmap) DrawTriangles(srcs [graphics.ShaderImageNum]*Mipmap, vertices []float32, indices []uint16, colorm *affine.ColorM, mode driver.CompositeMode, filter driver.Filter, address driver.Address, sourceRegion driver.Region, subimageOffsets [graphics.ShaderImageNum - 1][2]float32, shader *Shader, uniforms []interface{}, canSkipMipmap bool) {
 	if len(indices) == 0 {
 		return
 	}
@@ -176,7 +176,7 @@ func (m *Mipmap) DrawTriangles(srcs [graphics.ShaderImageNum]*Mipmap, vertices [
 		imgs[i] = src.orig
 	}
 
-	m.orig.DrawTriangles(imgs, vertices, indices, colorm, mode, filter, address, sourceRegion, s, uniforms)
+	m.orig.DrawTriangles(imgs, vertices, indices, colorm, mode, filter, address, sourceRegion, subimageOffsets, s, uniforms)
 	m.disposeMipmaps()
 }
 
@@ -238,7 +238,7 @@ func (m *Mipmap) level(level int) *buffered.Image {
 	}
 	s := buffered.NewImage(w2, h2)
 	s.SetVolatile(m.volatile)
-	s.DrawTriangles([graphics.ShaderImageNum]*buffered.Image{src}, vs, is, nil, driver.CompositeModeCopy, filter, driver.AddressUnsafe, driver.Region{}, nil, nil)
+	s.DrawTriangles([graphics.ShaderImageNum]*buffered.Image{src}, vs, is, nil, driver.CompositeModeCopy, filter, driver.AddressUnsafe, driver.Region{}, [graphics.ShaderImageNum - 1][2]float32{}, nil, nil)
 	m.imgs[level] = s
 
 	return m.imgs[level]

internal/shareable/image.go

@@ -306,7 +306,7 @@ func (i *Image) processSrc(src *Image) {
 //   5: Color G
 //   6: Color B
 //   7: Color Y
-func (i *Image) DrawTriangles(srcs [graphics.ShaderImageNum]*Image, vertices []float32, indices []uint16, colorm *affine.ColorM, mode driver.CompositeMode, filter driver.Filter, address driver.Address, sourceRegion driver.Region, shader *Shader, uniforms []interface{}) {
+func (i *Image) DrawTriangles(srcs [graphics.ShaderImageNum]*Image, vertices []float32, indices []uint16, colorm *affine.ColorM, mode driver.CompositeMode, filter driver.Filter, address driver.Address, sourceRegion driver.Region, subimageOffsets [graphics.ShaderImageNum - 1][2]float32, shader *Shader, uniforms []interface{}) {
 	backendsM.Lock()
 	// Do not use defer for performance.
 
@@ -362,8 +362,8 @@ func (i *Image) DrawTriangles(srcs [graphics.ShaderImageNum]*Image, vertices []f
 		ox, oy, _, _ := src.regionWithPadding()
 		ox += paddingSize
 		oy += paddingSize
-		offsets[i][0] = float32(ox) - oxf
+		offsets[i][0] = float32(ox) - oxf + subimageOffsets[i][0]
-		offsets[i][1] = float32(oy) - oyf
+		offsets[i][1] = float32(oy) - oyf + subimageOffsets[i][0]
 	}
 
 	var s *restorable.Shader

internal/shareable/image_test.go

@@ -96,7 +96,7 @@ func TestEnsureNotShared(t *testing.T) {
 	// img4.ensureNotShared() should be called.
 	vs := quadVertices(size/2, size/2, size/4, size/4, 1)
 	is := graphics.QuadIndices()
-	img4.DrawTriangles([graphics.ShaderImageNum]*Image{img3}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, nil, nil)
+	img4.DrawTriangles([graphics.ShaderImageNum]*Image{img3}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, [graphics.ShaderImageNum - 1][2]float32{}, nil, nil)
 	want := false
 	if got := img4.IsSharedForTesting(); got != want {
 		t.Errorf("got: %v, want: %v", got, want)
@@ -126,7 +126,7 @@ func TestEnsureNotShared(t *testing.T) {
 
 	// Check further drawing doesn't cause panic.
 	// This bug was fixed by 03dcd948.
-	img4.DrawTriangles([graphics.ShaderImageNum]*Image{img3}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, nil, nil)
+	img4.DrawTriangles([graphics.ShaderImageNum]*Image{img3}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, [graphics.ShaderImageNum - 1][2]float32{}, nil, nil)
 }
 
 func TestReshared(t *testing.T) {
@@ -167,7 +167,7 @@ func TestReshared(t *testing.T) {
 	// Use img1 as a render target.
 	vs := quadVertices(size, size, 0, 0, 1)
 	is := graphics.QuadIndices()
-	img1.DrawTriangles([graphics.ShaderImageNum]*Image{img2}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, nil, nil)
+	img1.DrawTriangles([graphics.ShaderImageNum]*Image{img2}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, [graphics.ShaderImageNum - 1][2]float32{}, nil, nil)
 	if got, want := img1.IsSharedForTesting(), false; got != want {
 		t.Errorf("got: %v, want: %v", got, want)
 	}
@@ -177,7 +177,7 @@ func TestReshared(t *testing.T) {
 		if err := MakeImagesSharedForTesting(); err != nil {
 			t.Fatal(err)
 		}
-		img0.DrawTriangles([graphics.ShaderImageNum]*Image{img1}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, nil, nil)
+		img0.DrawTriangles([graphics.ShaderImageNum]*Image{img1}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, [graphics.ShaderImageNum - 1][2]float32{}, nil, nil)
 		if got, want := img1.IsSharedForTesting(), false; got != want {
 			t.Errorf("got: %v, want: %v", got, want)
 		}
@@ -204,7 +204,7 @@ func TestReshared(t *testing.T) {
 		}
 	}
 
-	img0.DrawTriangles([graphics.ShaderImageNum]*Image{img1}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, nil, nil)
+	img0.DrawTriangles([graphics.ShaderImageNum]*Image{img1}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, [graphics.ShaderImageNum - 1][2]float32{}, nil, nil)
 	if got, want := img1.IsSharedForTesting(), true; got != want {
 		t.Errorf("got: %v, want: %v", got, want)
 	}
@@ -232,7 +232,7 @@ func TestReshared(t *testing.T) {
 		if err := MakeImagesSharedForTesting(); err != nil {
 			t.Fatal(err)
 		}
-		img0.DrawTriangles([graphics.ShaderImageNum]*Image{img3}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, nil, nil)
+		img0.DrawTriangles([graphics.ShaderImageNum]*Image{img3}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, [graphics.ShaderImageNum - 1][2]float32{}, nil, nil)
 		if got, want := img3.IsSharedForTesting(), false; got != want {
 			t.Errorf("got: %v, want: %v", got, want)
 		}
@@ -327,7 +327,7 @@ func TestReplacePixelsAfterDrawTriangles(t *testing.T) {
 
 	vs := quadVertices(w, h, 0, 0, 1)
 	is := graphics.QuadIndices()
-	dst.DrawTriangles([graphics.ShaderImageNum]*Image{src}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, nil, nil)
+	dst.DrawTriangles([graphics.ShaderImageNum]*Image{src}, vs, is, nil, driver.CompositeModeCopy, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, [graphics.ShaderImageNum - 1][2]float32{}, nil, nil)
 	dst.ReplacePixels(pix)
 
 	pix, err := dst.Pixels(0, 0, w, h)
@@ -369,7 +369,7 @@ func TestSmallImages(t *testing.T) {
 
 	vs := quadVertices(w, h, 0, 0, 1)
 	is := graphics.QuadIndices()
-	dst.DrawTriangles([graphics.ShaderImageNum]*Image{src}, vs, is, nil, driver.CompositeModeSourceOver, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, nil, nil)
+	dst.DrawTriangles([graphics.ShaderImageNum]*Image{src}, vs, is, nil, driver.CompositeModeSourceOver, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, [graphics.ShaderImageNum - 1][2]float32{}, nil, nil)
 
 	pix, err := dst.Pixels(0, 0, w, h)
 	if err != nil {
@@ -411,7 +411,7 @@ func TestLongImages(t *testing.T) {
 	const scale = 120
 	vs := quadVertices(w, h, 0, 0, scale)
 	is := graphics.QuadIndices()
-	dst.DrawTriangles([graphics.ShaderImageNum]*Image{src}, vs, is, nil, driver.CompositeModeSourceOver, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, nil, nil)
+	dst.DrawTriangles([graphics.ShaderImageNum]*Image{src}, vs, is, nil, driver.CompositeModeSourceOver, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, [graphics.ShaderImageNum - 1][2]float32{}, nil, nil)
 
 	pix, err := dst.Pixels(0, 0, dstW, dstH)
 	if err != nil {

shader_test.go

@@ -15,6 +15,7 @@
 package ebiten_test
 
 import (
+	"image"
 	"image/color"
 	"testing"
 
@@ -798,3 +799,66 @@ func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
 		}
 	}
 }
+
+func TestShaderSubImage(t *testing.T) {
+	const w, h = 16, 16
+
+	dst, _ := NewImage(w, h, FilterDefault)
+	s, err := NewShader([]byte(`package main
+
+func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
+	r := imageSrc0At(texCoord).r
+	g := imageSrc1At(texCoord).g
+	return vec4(r, g, 0, 1)
+}
+`))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	src0, _ := NewImage(w, h, FilterDefault)
+	pix0 := make([]byte, 4*w*h)
+	for j := 0; j < h; j++ {
+		for i := 0; i < w; i++ {
+			if 2 <= i && i < 10 && 2 <= j && j < 10 {
+				pix0[4*(j*w+i)] = 0xff
+				pix0[4*(j*w+i)+1] = 0
+				pix0[4*(j*w+i)+2] = 0
+				pix0[4*(j*w+i)+3] = 0xff
+			}
+		}
+	}
+	src0.ReplacePixels(pix0)
+
+	src1, _ := NewImage(w, h, FilterDefault)
+	pix1 := make([]byte, 4*w*h)
+	for j := 0; j < h; j++ {
+		for i := 0; i < w; i++ {
+			if 6 <= i && i < 14 && 6 <= j && j < 14 {
+				pix1[4*(j*w+i)] = 0
+				pix1[4*(j*w+i)+1] = 0xff
+				pix1[4*(j*w+i)+2] = 0
+				pix1[4*(j*w+i)+3] = 0xff
+			}
+		}
+	}
+	src1.ReplacePixels(pix1)
+
+	op := &DrawRectShaderOptions{}
+	op.Images[0] = src0.SubImage(image.Rect(2, 2, 10, 10)).(*Image)
+	op.Images[1] = src1.SubImage(image.Rect(6, 6, 14, 14)).(*Image)
+	dst.DrawRectShader(w/2, h/2, s, op)
+
+	for j := 0; j < h; j++ {
+		for i := 0; i < w; i++ {
+			got := dst.At(i, j).(color.RGBA)
+			var want color.RGBA
+			if i < w/2 && j < h/2 {
+				want = color.RGBA{0xff, 0xff, 0, 0xff}
+			}
+			if got != want {
+				t.Errorf("dst.At(%d, %d): got: %v, want: %v", i, j, got, want)
+			}
+		}
+	}
+}