From cb26342b3d2382476e57fbaa5677d4d8c13e4e3d Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Wed, 14 Jan 2015 23:29:14 +0900
Subject: [PATCH] Bug fix (#85): The limit of the size of vertices was wrong

---
 example/sprites/main.go                      | 2 +-
 internal/graphics/internal/shader/draw.go    | 4 +---
 internal/graphics/internal/shader/program.go | 5 +++--
 internal/opengl/context_js.go                | 1 -
 4 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/example/sprites/main.go b/example/sprites/main.go
index e2b4b6916..450edd09c 100644
--- a/example/sprites/main.go
+++ b/example/sprites/main.go
@@ -92,7 +92,7 @@ func (s Sprites) Src(i int) (x0, y0, x1, y1 int) {
 	return s[i].Src()
 }
 
-var sprites = make(Sprites, 2500)
+var sprites = make(Sprites, 10000)
 
 func update(screen *ebiten.Image) error {
 	sprites.Update()
diff --git a/internal/graphics/internal/shader/draw.go b/internal/graphics/internal/shader/draw.go
index 9e6a00519..8da5a96d0 100644
--- a/internal/graphics/internal/shader/draw.go
+++ b/internal/graphics/internal/shader/draw.go
@@ -58,9 +58,7 @@ func DrawTexture(c *opengl.Context, texture opengl.Texture, projectionMatrix *[4
 	if quads.Len() == 0 {
 		return nil
 	}
-	// TODO: Change this panic if image.DrawImage allows more than quadsMaxNum parts.
-	// TODO: Kinder message
-	if quadsMaxNum < 4*quads.Len() {
+	if quadsMaxNum < quads.Len() {
 		return errors.New(fmt.Sprintf("len(quads) must be equal to or less than %d", quadsMaxNum))
 	}
 
diff --git a/internal/graphics/internal/shader/program.go b/internal/graphics/internal/shader/program.go
index 2fd343895..4e4f7b4e0 100644
--- a/internal/graphics/internal/shader/program.go
+++ b/internal/graphics/internal/shader/program.go
@@ -23,7 +23,7 @@ var (
 	programRect    opengl.Program
 )
 
-const quadsMaxNum = 10000
+const quadsMaxNum = 65536 / 6
 
 func initialize(c *opengl.Context) error {
 	const uint16Size = 2
@@ -63,7 +63,8 @@ func initialize(c *opengl.Context) error {
 	}
 
 	const stride = 4 * 4
-	c.NewBuffer(c.ArrayBuffer, stride*quadsMaxNum, c.DynamicDraw)
+	const float32Size = 4
+	c.NewBuffer(c.ArrayBuffer, float32Size*stride*quadsMaxNum, c.DynamicDraw)
 
 	indices := make([]uint16, 6*quadsMaxNum)
 	for i := uint16(0); i < quadsMaxNum; i++ {
diff --git a/internal/opengl/context_js.go b/internal/opengl/context_js.go
index b6ef1a584..6e22b4198 100644
--- a/internal/opengl/context_js.go
+++ b/internal/opengl/context_js.go
@@ -267,7 +267,6 @@ func (c *Context) NewBuffer(bufferType BufferType, v interface{}, bufferUsageTyp
 
 func (c *Context) BufferSubData(bufferType BufferType, data []float32) {
 	gl := c.gl
-	const float32Size = 4
 	gl.BufferSubData(int(bufferType), 0, data)
 }