buffered: Bug fix: Pixel data was not invalidated after DrawImage/Triangles

image_test.go

@@ -2172,3 +2172,27 @@ func TestImageFloatTranslate(t *testing.T) {
 		})
 	}
 }
+
+// Issue #1213
+func TestImageColorMCopy(t *testing.T) {
+	const w, h = 16, 16
+	dst, _ := NewImage(w, h, FilterDefault)
+	src, _ := NewImage(w, h, FilterDefault)
+
+	for k := 0; k < 256; k++ {
+		op := &DrawImageOptions{}
+		op.ColorM.Translate(float64(k)/0xff, 1, 1, 1)
+		op.CompositeMode = CompositeModeCopy
+		dst.DrawImage(src, op)
+
+		for j := 0; j < h; j++ {
+			for i := 0; i < w; i++ {
+				got := dst.At(i, j).(color.RGBA)
+				want := color.RGBA{byte(k), 0xff, 0xff, 0xff}
+				if !sameColors(got, want, 1) {
+					t.Fatalf("dst.At(%d, %d), k: %d: got %v, want %v", i, j, k, got, want)
+				}
+			}
+		}
+	}
+}

internal/buffered/image.go

@@ -275,6 +275,7 @@ func (i *Image) drawImage(src *Image, bounds image.Rectangle, g mipmap.GeoM, col
 	src.resolvePendingPixels(true)
 	i.resolvePendingPixels(false)
 	i.img.DrawImage(src.img, bounds, g, colorm, mode, filter)
+	i.invalidatePendingPixels()
 }
 
 // DrawTriangles draws the src image with the given vertices.
@@ -329,6 +330,7 @@ func (i *Image) DrawTriangles(src *Image, vertices []float32, indices []uint16,
 		srcImg = src.img
 	}
 	i.img.DrawTriangles(srcImg, vertices, indices, colorm, mode, filter, address, s, us)
+	i.invalidatePendingPixels()
 }
 
 type Shader struct {