From 2a7caf7755eb76719beeed986bb14ab40e8282a2 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sun, 4 Nov 2018 19:06:13 +0900
Subject: [PATCH] opengl: Move ensureFramebuffer to opengl.Image

---
 internal/graphicscommand/command.go | 18 ++++-------
 internal/graphicscommand/image.go   | 14 ---------
 internal/opengl/context.go          |  2 +-
 internal/opengl/framebuffer.go      |  6 ++--
 internal/opengl/image.go            | 46 ++++++++++++++++++++++++++++-
 5 files changed, 54 insertions(+), 32 deletions(-)

diff --git a/internal/graphicscommand/command.go b/internal/graphicscommand/command.go
index 76f2148c5..45be7da50 100644
--- a/internal/graphicscommand/command.go
+++ b/internal/graphicscommand/command.go
@@ -228,21 +228,18 @@ func (c *drawImageCommand) String() string {
 
 // Exec executes the drawImageCommand.
 func (c *drawImageCommand) Exec(indexOffsetInBytes int) error {
-	f, err := c.dst.ensureFramebuffer()
-	if err != nil {
-		return err
-	}
-
 	// On some environments, viewport size must be within the framebuffer size.
 	// e.g. Edge (#71), Chrome on GPD Pocket (#420), macOS Mojave (#691).
 	// Use the same size of the framebuffer here.
-	opengl.GetContext().SetViewport(f)
+	if err := c.dst.image.SetViewport(); err != nil {
+		return err
+	}
 	opengl.GetContext().BlendFunc(c.mode)
 
 	if c.nindices == 0 {
 		return nil
 	}
-	proj := f.ProjectionMatrix()
+	proj := c.dst.image.ProjectionMatrix()
 	dw, dh := c.dst.Size()
 	sw, sh := c.src.Size()
 	opengl.UseProgram(proj, c.src.image, dw, dh, sw, sh, c.color, c.filter)
@@ -340,12 +337,7 @@ type pixelsCommand struct {
 
 // Exec executes a pixelsCommand.
 func (c *pixelsCommand) Exec(indexOffsetInBytes int) error {
-	f, err := c.img.ensureFramebuffer()
-	if err != nil {
-		return err
-	}
-	w, h := c.img.Size()
-	p, err := opengl.GetContext().FramebufferPixels(f, w, h)
+	p, err := c.img.image.Pixels()
 	if err != nil {
 		return err
 	}
diff --git a/internal/graphicscommand/image.go b/internal/graphicscommand/image.go
index 1b33aaa13..f53672866 100644
--- a/internal/graphicscommand/image.go
+++ b/internal/graphicscommand/image.go
@@ -17,7 +17,6 @@ package graphicscommand
 import (
 	"github.com/hajimehoshi/ebiten/internal/affine"
 	"github.com/hajimehoshi/ebiten/internal/graphics"
-	"github.com/hajimehoshi/ebiten/internal/math"
 	"github.com/hajimehoshi/ebiten/internal/opengl"
 )
 
@@ -115,16 +114,3 @@ func (i *Image) ReplacePixels(p []byte, x, y, width, height int) {
 func (i *Image) IsInvalidated() bool {
 	return i.image.IsInvalidated()
 }
-
-func (i *Image) ensureFramebuffer() (*opengl.Framebuffer, error) {
-	if i.image.Framebuffer != nil {
-		return i.image.Framebuffer, nil
-	}
-	w, h := i.image.Size()
-	f, err := opengl.NewFramebufferFromTexture(i.image.Texture, math.NextPowerOf2Int(w), math.NextPowerOf2Int(h))
-	if err != nil {
-		return nil, err
-	}
-	i.image.Framebuffer = f
-	return i.image.Framebuffer, nil
-}
diff --git a/internal/opengl/context.go b/internal/opengl/context.go
index 7afb3c2f0..e0f66d295 100644
--- a/internal/opengl/context.go
+++ b/internal/opengl/context.go
@@ -96,7 +96,7 @@ func (c *Context) bindFramebuffer(f framebufferNative) {
 	c.lastFramebuffer = f
 }
 
-func (c *Context) SetViewport(f *Framebuffer) {
+func (c *Context) setViewport(f *Framebuffer) {
 	c.bindFramebuffer(f.native)
 	if c.lastViewportWidth != f.width || c.lastViewportHeight != f.height {
 		c.setViewportImpl(f.width, f.height)
diff --git a/internal/opengl/framebuffer.go b/internal/opengl/framebuffer.go
index e4dd06670..66abf2996 100644
--- a/internal/opengl/framebuffer.go
+++ b/internal/opengl/framebuffer.go
@@ -46,12 +46,12 @@ func NewScreenFramebuffer(width, height int) *Framebuffer {
 	}
 }
 
-// ProjectionMatrix returns a projection matrix of the framebuffer.
+// projectionMatrix returns a projection matrix of the framebuffer.
 //
 // A projection matrix converts the coodinates on the framebuffer
 // (0, 0) - (viewport width, viewport height)
 // to the normalized device coodinates (-1, -1) - (1, 1) with adjustment.
-func (f *Framebuffer) ProjectionMatrix() []float32 {
+func (f *Framebuffer) projectionMatrix() []float32 {
 	if f.proMatrix != nil {
 		return f.proMatrix
 	}
@@ -59,7 +59,7 @@ func (f *Framebuffer) ProjectionMatrix() []float32 {
 	return f.proMatrix
 }
 
-func (f *Framebuffer) Delete() {
+func (f *Framebuffer) delete() {
 	if f.native != theContext.getScreenFramebuffer() {
 		theContext.deleteFramebuffer(f.native)
 	}
diff --git a/internal/opengl/image.go b/internal/opengl/image.go
index a3601f2f2..a68b0fc99 100644
--- a/internal/opengl/image.go
+++ b/internal/opengl/image.go
@@ -14,6 +14,10 @@
 
 package opengl
 
+import (
+	"github.com/hajimehoshi/ebiten/internal/math"
+)
+
 type Image struct {
 	Texture     Texture
 	Framebuffer *Framebuffer
@@ -38,9 +42,49 @@ func (i *Image) IsInvalidated() bool {
 
 func (i *Image) Delete() {
 	if i.Framebuffer != nil {
-		i.Framebuffer.Delete()
+		i.Framebuffer.delete()
 	}
 	if i.Texture != *new(Texture) {
 		theContext.deleteTexture(i.Texture)
 	}
 }
+
+func (i *Image) SetViewport() error {
+	if err := i.ensureFramebuffer(); err != nil {
+		return err
+	}
+	theContext.setViewport(i.Framebuffer)
+	return nil
+}
+
+func (i *Image) Pixels() ([]byte, error) {
+	if err := i.ensureFramebuffer(); err != nil {
+		return nil, err
+	}
+	w, h := i.Size()
+	p, err := theContext.FramebufferPixels(i.Framebuffer, w, h)
+	if err != nil {
+		return nil, err
+	}
+	return p, nil
+}
+
+func (i *Image) ProjectionMatrix() []float32 {
+	if i.Framebuffer == nil {
+		panic("not reached")
+	}
+	return i.Framebuffer.projectionMatrix()
+}
+
+func (i *Image) ensureFramebuffer() error {
+	if i.Framebuffer != nil {
+		return nil
+	}
+	w, h := i.Size()
+	f, err := NewFramebufferFromTexture(i.Texture, math.NextPowerOf2Int(w), math.NextPowerOf2Int(h))
+	if err != nil {
+		return err
+	}
+	i.Framebuffer = f
+	return nil
+}