graphics: Move makeing vertices from drawTexture to textureQuads to avoid copying

imageparts.go

@@ -15,9 +15,11 @@
 package ebiten
 
 import (
-	"github.com/hajimehoshi/ebiten/internal/graphics"
+	"fmt"
 	"image"
 	"math"
+
+	"github.com/hajimehoshi/ebiten/internal/graphics"
 )
 
 // Deprecated (as of 1.1.0-alpha): Use ImageParts instead.
@@ -85,12 +87,33 @@ func (t *textureQuads) Len() int {
 	return t.parts.Len()
 }
 
-func (t *textureQuads) Vertex(i int) (x0, y0, x1, y1 int) {
-	return t.parts.Dst(i)
-}
-
-func (t *textureQuads) Texture(i int) (u0, v0, u1, v1 int) {
-	x0, y0, x1, y1 := t.parts.Src(i)
+func (t *textureQuads) SetVertices(vertices []int16) error {
+	l := t.Len()
+	if len(vertices) < l*16 {
+		return fmt.Errorf("grphics: vertices size must be greater than %d but %d", l*16, len(vertices))
+	}
+	p := t.parts
 	w, h := t.width, t.height
-	return u(x0, w), v(y0, h), u(x1, w), v(y1, h)
+	for i := 0; i < l; i++ {
+		x0, y0, x1, y1 := p.Dst(i)
+		sx0, sy0, sx1, sy1 := p.Src(i)
+		u0, v0, u1, v1 := u(sx0, w), v(sy0, h), u(sx1, w), v(sy1, h)
+		vertices[16*i] = int16(x0)
+		vertices[16*i+1] = int16(y0)
+		vertices[16*i+2] = int16(u0)
+		vertices[16*i+3] = int16(v0)
+		vertices[16*i+4] = int16(x1)
+		vertices[16*i+5] = int16(y0)
+		vertices[16*i+6] = int16(u1)
+		vertices[16*i+7] = int16(v0)
+		vertices[16*i+8] = int16(x0)
+		vertices[16*i+9] = int16(y1)
+		vertices[16*i+10] = int16(u0)
+		vertices[16*i+11] = int16(v1)
+		vertices[16*i+12] = int16(x1)
+		vertices[16*i+13] = int16(y1)
+		vertices[16*i+14] = int16(u1)
+		vertices[16*i+15] = int16(v1)
+	}
+	return nil
 }

internal/graphics/draw.go

@@ -48,11 +48,10 @@ func drawTexture(c *opengl.Context, texture opengl.Texture, projectionMatrix *[4
 		shadersInitialized = true
 	}
 
-	l := quads.Len()
-	if l == 0 {
+	if quads.Len() == 0 {
 		return nil
 	}
-	if quadsMaxNum < l {
+	if quadsMaxNum < quads.Len() {
 		return errors.New(fmt.Sprintf("len(quads) must be equal to or less than %d", quadsMaxNum))
 	}
 
@@ -66,26 +65,8 @@ func drawTexture(c *opengl.Context, texture opengl.Texture, projectionMatrix *[4
 	}
 	p.begin()
 	defer p.end()
-
-	for i := 0; i < l; i++ {
-		x0, y0, x1, y1 := quads.Vertex(i)
-		u0, v0, u1, v1 := quads.Texture(i)
-		vertices[16*i] = int16(x0)
-		vertices[16*i+1] = int16(y0)
-		vertices[16*i+2] = int16(u0)
-		vertices[16*i+3] = int16(v0)
-		vertices[16*i+4] = int16(x1)
-		vertices[16*i+5] = int16(y0)
-		vertices[16*i+6] = int16(u1)
-		vertices[16*i+7] = int16(v0)
-		vertices[16*i+8] = int16(x0)
-		vertices[16*i+9] = int16(y1)
-		vertices[16*i+10] = int16(u0)
-		vertices[16*i+11] = int16(v1)
-		vertices[16*i+12] = int16(x1)
-		vertices[16*i+13] = int16(y1)
-		vertices[16*i+14] = int16(u1)
-		vertices[16*i+15] = int16(v1)
+	if err := quads.SetVertices(vertices); err != nil {
+		return err
 	}
 	c.BufferSubData(c.ArrayBuffer, vertices[:16*quads.Len()])
 	c.DrawElements(c.Triangles, 6*quads.Len())

internal/graphics/framebuffer.go

@@ -22,8 +22,7 @@ import (
 
 type TextureQuads interface {
 	Len() int
-	Vertex(i int) (x0, y0, x1, y1 int)
-	Texture(i int) (u0, v0, u1, v1 int)
+	SetVertices(vertices []int16) error
 }
 
 type Lines interface {