gpu: remove Backend.Resize and fully specify format in Backend.NewTexture

Re-create textures instead to better match direct3d.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

gpu/backend.go

@@ -18,7 +18,7 @@ type Backend interface {
 	// IsContinuousTime reports whether all timer measurements
 	// are valid at the point of call.
 	IsTimeContinuous() bool
-	NewTexture(minFilter, magFilter TextureFilter) Texture
+	NewTexture(format TextureFormat, width, height int, minFilter, magFilter TextureFilter) Texture
 	DefaultFramebuffer() Framebuffer
 	NilTexture() Texture
 	NewFramebuffer() Framebuffer
@@ -143,7 +143,6 @@ type Texture interface {
 	Upload(img *image.RGBA)
 	Release()
 	Bind(unit int)
-	Resize(format TextureFormat, width, height int)
 }
 
 const (

gpu/gl/backend.go

@@ -53,6 +53,7 @@ type gpuTimer struct {
 type gpuTexture struct {
 	backend *Backend
 	obj     Texture
+	triple  textureTriple
 }
 
 type gpuFramebuffer struct {
@@ -174,13 +175,22 @@ func (b *Backend) DefaultFramebuffer() gpu.Framebuffer {
 	return b.defFBO
 }
 
-func (b *Backend) NewTexture(minFilter, magFilter gpu.TextureFilter) gpu.Texture {
+func (b *Backend) NewTexture(format gpu.TextureFormat, width, height int, minFilter, magFilter gpu.TextureFilter) gpu.Texture {
 	tex := &gpuTexture{backend: b, obj: b.funcs.CreateTexture()}
+	switch format {
+	case gpu.TextureFormatFloat:
+		tex.triple = b.floatTriple
+	case gpu.TextureFormatSRGB:
+		tex.triple = b.srgbaTriple
+	default:
+		panic("unsupported texture format")
+	}
 	tex.Bind(0)
 	b.funcs.TexParameteri(TEXTURE_2D, TEXTURE_MAG_FILTER, toTexFilter(magFilter))
 	b.funcs.TexParameteri(TEXTURE_2D, TEXTURE_MIN_FILTER, toTexFilter(minFilter))
 	b.funcs.TexParameteri(TEXTURE_2D, TEXTURE_WRAP_S, CLAMP_TO_EDGE)
 	b.funcs.TexParameteri(TEXTURE_2D, TEXTURE_WRAP_T, CLAMP_TO_EDGE)
+	b.funcs.TexImage2D(TEXTURE_2D, 0, tex.triple.internalFormat, width, height, tex.triple.format, tex.triple.typ, nil)
 	return tex
 }
 
@@ -571,12 +581,6 @@ func (t *gpuTexture) Release() {
 	t.backend.funcs.DeleteTexture(t.obj)
 }
 
-func (t *gpuTexture) Resize(format gpu.TextureFormat, width, height int) {
-	t.Bind(0)
-	tt := t.backend.floatTriple
-	t.backend.funcs.TexImage2D(TEXTURE_2D, 0, tt.internalFormat, width, height, tt.format, tt.typ, nil)
-}
-
 func (t *gpuTexture) Upload(img *image.RGBA) {
 	t.Bind(0)
 	var pixels []byte
@@ -588,8 +592,7 @@ func (t *gpuTexture) Upload(img *image.RGBA) {
 	start := (b.Min.X + b.Min.Y*w) * 4
 	end := (b.Max.X + (b.Max.Y-1)*w) * 4
 	pixels = img.Pix[start:end]
-	tt := t.backend.srgbaTriple
+	t.backend.funcs.TexImage2D(TEXTURE_2D, 0, t.triple.internalFormat, w, h, t.triple.format, t.triple.typ, pixels)
-	t.backend.funcs.TexImage2D(TEXTURE_2D, 0, tt.internalFormat, w, h, tt.format, tt.typ, pixels)
 }
 
 func (t *gpuTimer) Begin() {

gpu/gpu.go

@@ -378,7 +378,7 @@ func (r *renderer) texHandle(t *texture) Texture {
 	if t.tex != nil {
 		return t.tex
 	}
-	t.tex = r.ctx.NewTexture(FilterLinear, FilterLinear)
+	t.tex = r.ctx.NewTexture(TextureFormatSRGB, t.src.Bounds().Dx(), t.src.Bounds().Dy(), FilterLinear, FilterLinear)
 	t.tex.Upload(t.src)
 	return t.tex
 }

gpu/path.go

@@ -195,7 +195,6 @@ func (s *fboSet) resize(ctx Backend, sizes []image.Point) {
 	for i := len(s.fbos); i < len(sizes); i++ {
 		s.fbos = append(s.fbos, stencilFBO{
 			fbo: ctx.NewFramebuffer(),
-			tex: ctx.NewTexture(FilterNearest, FilterNearest),
 		})
 	}
 	// Resize fbos.
@@ -207,8 +206,11 @@ func (s *fboSet) resize(ctx Backend, sizes []image.Point) {
 		waste := float32(sz.X*sz.Y) / float32(f.size.X*f.size.Y)
 		resize = resize || waste > 1.2
 		if resize {
+			if f.tex != nil {
+				f.tex.Release()
+			}
 			f.size = sz
-			f.tex.Resize(TextureFormatFloat, sz.X, sz.Y)
+			f.tex = ctx.NewTexture(TextureFormatFloat, sz.X, sz.Y, FilterNearest, FilterNearest)
 			f.fbo.BindTexture(f.tex)
 		}
 	}