diff --git a/pixelgl/canvas.go b/pixelgl/canvas.go
index 4d45592759192f5ddf313f3a9fb86af136725fac..4b94fd21b657be13052f6f157f4314e7973a0ddf 100644
--- a/pixelgl/canvas.go
+++ b/pixelgl/canvas.go
@@ -12,8 +12,6 @@ import (
"github.com/pkg/errors"
)
-//TODO: make Canvas a Picture
-
// Canvas is an off-screen rectangular BasicTarget that you can draw onto.
//
// It supports TrianglesPosition, TrianglesColor, TrianglesPicture and PictureColor.
@@ -26,8 +24,11 @@ type Canvas struct {
mat mgl32.Mat3
col mgl32.Vec4
- borders pixel.Rect
- bounds pixel.Rect
+ pixels []uint8
+ dirty bool
+
+ bounds pixel.Rect
+ orig *Canvas
}
// NewCanvas creates a new empty, fully transparent Canvas with given bounds. If the smooth flag
@@ -38,6 +39,7 @@ func NewCanvas(bounds pixel.Rect, smooth bool) *Canvas {
mat: mgl32.Ident3(),
col: mgl32.Vec4{1, 1, 1, 1},
}
+ c.orig = c
mainthread.Call(func() {
var err error
@@ -79,7 +81,7 @@ func (c *Canvas) MakePicture(p pixel.Picture) pixel.TargetPicture {
}
bounds := p.Bounds()
- bx, by, bw, bh := discreteBounds(bounds)
+ bx, by, bw, bh := intBounds(bounds)
pixels := make([]uint8, 4*bw*bh)
if p, ok := p.(pixel.PictureColor); ok {
@@ -138,6 +140,9 @@ func (c *Canvas) SetColorMask(col color.Color) {
}
// SetBounds resizes the Canvas to the new bounds. Old content will be preserved.
+//
+// If this Canvas was created using Slice-ing, then the relation between this Canvas and it's
+// Original is unspecified (but Original will always return valid stuff).
func (c *Canvas) SetBounds(bounds pixel.Rect) {
if c.Bounds() == bounds {
return
@@ -146,14 +151,14 @@ func (c *Canvas) SetBounds(bounds pixel.Rect) {
mainthread.Call(func() {
oldF := c.f
- _, _, w, h := discreteBounds(bounds)
+ _, _, w, h := intBounds(bounds)
c.f = glhf.NewFrame(w, h, c.smooth)
// preserve old content
if oldF != nil {
relBounds := c.bounds
relBounds.Pos -= bounds.Pos
- ox, oy, ow, oh := discreteBounds(relBounds)
+ ox, oy, ow, oh := intBounds(relBounds)
oldF.Blit(
c.f,
ox, oy, ox+ow, oy+oh,
@@ -161,8 +166,10 @@ func (c *Canvas) SetBounds(bounds pixel.Rect) {
)
}
})
- c.borders = bounds
+
c.bounds = bounds
+ c.orig = c // detach from the Original
+ c.dirty = true
}
// Bounds returns the rectangular bounds of the Canvas.
@@ -182,10 +189,22 @@ func (c *Canvas) Smooth() bool {
return c.smooth
}
+// must be manually called inside mainthread
+func (c *Canvas) setGlhfBounds() {
+ bounds := c.bounds
+ bounds.Pos -= c.orig.bounds.Pos
+ bx, by, bw, bh := intBounds(bounds)
+ glhf.Bounds(bx, by, bw, bh)
+}
+
// Clear fill the whole Canvas with a single color.
func (c *Canvas) Clear(color color.Color) {
+ c.orig.dirty = true
+
nrgba := pixel.NRGBAModel.Convert(color).(pixel.NRGBA)
+
mainthread.CallNonBlock(func() {
+ c.setGlhfBounds()
c.f.Begin()
glhf.Clear(
float32(nrgba.R),
@@ -197,6 +216,49 @@ func (c *Canvas) Clear(color color.Color) {
})
}
+// Slice returns a sub-Canvas with the specified Bounds.
+//
+// The returned value is *Canvas, the type of the return value is a general pixel.Picture just so
+// that Canvas implements pixel.Picture interface.
+func (c *Canvas) Slice(bounds pixel.Rect) pixel.Picture {
+ sc := new(Canvas)
+ *sc = *c
+ sc.bounds = bounds
+ return sc
+}
+
+// Original returns the most original Canvas that this Canvas was created from using Slice-ing.
+//
+// The returned value is *Canvas, the type of the return value is a general pixel.Picture just so
+// that Canvas implements pixel.Picture interface.
+func (c *Canvas) Original() pixel.Picture {
+ return c.orig
+}
+
+// Color returns the color of the pixel over the given position inside the Canvas.
+func (c *Canvas) Color(at pixel.Vec) pixel.NRGBA {
+ if c.orig.dirty {
+ mainthread.Call(func() {
+ c.f.Texture.Begin()
+ c.orig.pixels = c.f.Texture.Pixels(0, 0, c.f.Texture.Width(), c.f.Texture.Height())
+ c.f.Texture.End()
+ })
+ c.orig.dirty = false
+ }
+ if !c.bounds.Contains(at) {
+ return pixel.NRGBA{}
+ }
+ bx, by, bw, _ := intBounds(c.orig.bounds)
+ x, y := int(at.X())-bx, int(at.Y())-by
+ off := y*bw + x
+ return pixel.NRGBA{
+ R: float64(c.orig.pixels[off*4+0]) / 255,
+ G: float64(c.orig.pixels[off*4+1]) / 255,
+ B: float64(c.orig.pixels[off*4+2]) / 255,
+ A: float64(c.orig.pixels[off*4+3]) / 255,
+ }
+}
+
type canvasTriangles struct {
*GLTriangles
@@ -204,24 +266,22 @@ type canvasTriangles struct {
}
func (ct *canvasTriangles) draw(cp *canvasPicture) {
+ ct.c.orig.dirty = true
+
// save the current state vars to avoid race condition
mat := ct.c.mat
col := ct.c.col
mainthread.CallNonBlock(func() {
- bounds := ct.c.bounds
- bounds.Pos -= ct.c.borders.Pos
- bx, by, bw, bh := discreteBounds(bounds)
- glhf.Bounds(bx, by, bw, bh)
-
+ ct.c.setGlhfBounds()
ct.c.f.Begin()
ct.c.s.Begin()
ct.c.s.SetUniformAttr(canvasBounds, mgl32.Vec4{
- float32(cp.c.bounds.X()),
- float32(cp.c.bounds.Y()),
- float32(cp.c.bounds.W()),
- float32(cp.c.bounds.H()),
+ float32(ct.c.bounds.X()),
+ float32(ct.c.bounds.Y()),
+ float32(ct.c.bounds.W()),
+ float32(ct.c.bounds.H()),
})
ct.c.s.SetUniformAttr(canvasTransform, mat)
ct.c.s.SetUniformAttr(canvasColorMask, col)
@@ -341,11 +401,12 @@ out vec2 Texture;
out float Intensity;
uniform mat3 transform;
+uniform vec4 borders;
uniform vec4 bounds;
void main() {
vec2 transPos = (transform * vec3(position, 1.0)).xy;
- vec2 normPos = 2 * (transPos - bounds.xy) / (bounds.zw) - vec2(1, 1);
+ vec2 normPos = (transPos - bounds.xy) / (bounds.zw) * 2 - vec2(1, 1);
gl_Position = vec4(normPos, 0.0, 1.0);
Color = color;
Texture = texture;
diff --git a/pixelgl/util.go b/pixelgl/util.go
index af054100a26785696c27af3e8a4724395607579b..0d4195debff069308a068421ef4d21950287131b 100644
--- a/pixelgl/util.go
+++ b/pixelgl/util.go
@@ -6,7 +6,7 @@ import (
"github.com/faiface/pixel"
)
-func discreteBounds(bounds pixel.Rect) (x, y, w, h int) {
+func intBounds(bounds pixel.Rect) (x, y, w, h int) {
x0 := int(math.Floor(bounds.Pos.X()))
y0 := int(math.Floor(bounds.Pos.Y()))
x1 := int(math.Ceil(bounds.Pos.X() + bounds.Size.X()))
diff --git a/pixelgl/window.go b/pixelgl/window.go
index 6d194f49de756b53237d1432849b90fa21431793..3f52a6648a1c096885cd8a36822e1bc79a475b2d 100644
--- a/pixelgl/window.go
+++ b/pixelgl/window.go
@@ -105,7 +105,7 @@ func NewWindow(cfg WindowConfig) (*Window, error) {
if currentWindow != nil {
share = currentWindow.window
}
- _, _, width, height := discreteBounds(cfg.Bounds)
+ _, _, width, height := intBounds(cfg.Bounds)
w.window, err = glfw.CreateWindow(
width,
height,
@@ -166,14 +166,14 @@ func (w *Window) Update() {
mainthread.Call(func() {
w.begin()
- glhf.Bounds(0, 0, w.canvas.f.Width(), w.canvas.f.Height())
+ glhf.Bounds(0, 0, w.canvas.f.Texture.Width(), w.canvas.f.Texture.Height())
glhf.Clear(0, 0, 0, 0)
w.canvas.f.Begin()
w.canvas.f.Blit(
nil,
- 0, 0, w.canvas.f.Width(), w.canvas.f.Height(),
- 0, 0, w.canvas.f.Width(), w.canvas.f.Height(),
+ 0, 0, w.canvas.f.Texture.Width(), w.canvas.f.Texture.Height(),
+ 0, 0, w.canvas.f.Texture.Width(), w.canvas.f.Texture.Height(),
)
w.canvas.f.End()
@@ -220,7 +220,7 @@ func (w *Window) SetTitle(title string) {
func (w *Window) SetBounds(bounds pixel.Rect) {
w.bounds = bounds
mainthread.Call(func() {
- _, _, width, height := discreteBounds(bounds)
+ _, _, width, height := intBounds(bounds)
w.window.SetSize(width, height)
})
}