graphics: Introduce Commands (WIP)

internal/graphics/command.go

@@ -0,0 +1,104 @@
+// Copyright 2016 Hajime Hoshi
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package graphics
+
+import (
+	"image/color"
+	"math"
+
+	"github.com/hajimehoshi/ebiten/internal/graphics/opengl"
+)
+
+type command interface {
+	Exec(context *opengl.Context) error
+}
+
+type commandQueue struct {
+	commands []command
+}
+
+var theCommandQueue = &commandQueue{
+	commands: []command{},
+}
+
+func (q *commandQueue) Enqueue(command command) {
+	q.commands = append(q.commands, command)
+}
+
+func (q *commandQueue) Exec(context *opengl.Context) error {
+	// TODO: Do optimizing before executing
+	for _, c := range q.commands {
+		if err := c.Exec(context); err != nil {
+			return err
+		}
+	}
+	q.commands = []command{}
+	return nil
+}
+
+type fillCommand struct {
+	dst   *Framebuffer
+	color color.Color
+}
+
+func (c *fillCommand) Exec(context *opengl.Context) error {
+	if err := c.dst.setAsViewport(context); err != nil {
+		return err
+	}
+	cr, cg, cb, ca := c.color.RGBA()
+	const max = math.MaxUint16
+	r := float64(cr) / max
+	g := float64(cg) / max
+	b := float64(cb) / max
+	a := float64(ca) / max
+	return context.FillFramebuffer(r, g, b, a)
+}
+
+type drawImageCommand struct {
+	dst      *Framebuffer
+	src      *Texture
+	vertices []int16
+	geo      Matrix
+	color    Matrix
+	mode     opengl.CompositeMode
+}
+
+func (c *drawImageCommand) Exec(context *opengl.Context) error {
+	if err := c.dst.setAsViewport(context); err != nil {
+		return err
+	}
+	p := c.dst.projectionMatrix()
+	return drawTexture(context, c.src.native, p, c.vertices, c.geo, c.color, c.mode)
+}
+
+type replacePixelsCommand struct {
+	dst     *Framebuffer
+	texture *Texture
+	pixels  []uint8
+}
+
+func (c *replacePixelsCommand) Exec(context *opengl.Context) error {
+	// Filling with non black or white color is required here for glTexSubImage2D.
+	// Very mysterious but this actually works (Issue #186)
+	if err := c.dst.setAsViewport(context); err != nil {
+		return err
+	}
+	if err := context.FillFramebuffer(0, 0, 0.5, 1); err != nil {
+		return err
+	}
+	context.BindTexture(c.texture.native)
+	context.TexSubImage2D(c.pixels, c.texture.width, c.texture.height)
+	return nil
+}

internal/graphics/framebuffer.go

@@ -16,7 +16,6 @@ package graphics
 
 import (
 	"image/color"
-	"math"
 
 	"github.com/hajimehoshi/ebiten/internal/graphics/opengl"
 )
@@ -99,25 +98,24 @@ func (f *Framebuffer) projectionMatrix() *[4][4]float64 {
 	return f.proMatrix
 }
 
-func (f *Framebuffer) Fill(c *opengl.Context, clr color.Color) error {
-	if err := f.setAsViewport(c); err != nil {
-		return err
+func (f *Framebuffer) Fill(context *opengl.Context, clr color.Color) error {
+	c := &fillCommand{
+		dst:   f,
+		color: clr,
 	}
-	cr, cg, cb, ca := clr.RGBA()
-	const max = math.MaxUint16
-	r := float64(cr) / max
-	g := float64(cg) / max
-	b := float64(cb) / max
-	a := float64(ca) / max
-	return c.FillFramebuffer(r, g, b, a)
+	return c.Exec(context)
 }
 
-func (f *Framebuffer) DrawTexture(c *opengl.Context, t *Texture, vertices []int16, geo, clr Matrix, mode opengl.CompositeMode) error {
-	if err := f.setAsViewport(c); err != nil {
-		return err
+func (f *Framebuffer) DrawTexture(context *opengl.Context, t *Texture, vertices []int16, geo, clr Matrix, mode opengl.CompositeMode) error {
+	c := &drawImageCommand{
+		dst:      f,
+		src:      t,
+		vertices: vertices,
+		geo:      geo,
+		color:    clr,
+		mode:     mode,
 	}
-	p := f.projectionMatrix()
-	return drawTexture(c, t.native, p, vertices, geo, clr, mode)
+	return c.Exec(context)
 }
 
 func (f *Framebuffer) Pixels(c *opengl.Context) ([]uint8, error) {
@@ -125,13 +123,11 @@ func (f *Framebuffer) Pixels(c *opengl.Context) ([]uint8, error) {
 	return c.FramebufferPixels(f.native, w, h)
 }
 
-func (f *Framebuffer) ReplacePixels(c *opengl.Context, t *Texture, p []uint8) error {
-	// Filling with non black or white color is required here for glTexSubImage2D.
-	// Very mysterious but this actually works (Issue #186)
-	if err := f.Fill(c, color.RGBA{0, 0, 0x01, 0xff}); err != nil {
-		return err
+func (f *Framebuffer) ReplacePixels(context *opengl.Context, t *Texture, p []uint8) error {
+	c := &replacePixelsCommand{
+		dst:     f,
+		texture: t,
+		pixels:  p,
 	}
-	c.BindTexture(t.native)
-	c.TexSubImage2D(p, t.width, t.height)
-	return nil
+	return c.Exec(context)
 }