From ce9274a29d6e803bb47e48bb84cf7e9640711083 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Thu, 23 Mar 2023 20:01:10 +0900
Subject: [PATCH] ebiten: remove the restriction for len(indices) at Draw*

Closes #2460
---
 image.go                    | 18 +++++-------------
 image_test.go               |  6 +++---
 internal/graphics/vertex.go |  4 ----
 3 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/image.go b/image.go
index 9d2367cba..e1ded5bba 100644
--- a/image.go
+++ b/image.go
@@ -391,12 +391,14 @@ type DrawTrianglesOptions struct {
 }
 
 // MaxIndicesCount is the maximum number of indices for DrawTriangles and DrawTrianglesShader.
-const MaxIndicesCount = graphics.IndicesCount
+//
+// Deprecated: as of v2.6. This constant is no longer used.
+const MaxIndicesCount = (1 << 16) / 3 * 3
 
 // MaxIndicesNum is the maximum number of indices for DrawTriangles and DrawTrianglesShader.
 //
-// Deprecated: as of v2.4. Use MaxIndicesCount instead.
-const MaxIndicesNum = graphics.IndicesCount
+// Deprecated: as of v2.4. This constant is no longer used.
+const MaxIndicesNum = MaxIndicesCount
 
 // DrawTriangles draws triangles with the specified vertices and their indices.
 //
@@ -410,8 +412,6 @@ const MaxIndicesNum = graphics.IndicesCount
 //
 // If len(indices) is not multiple of 3, DrawTriangles panics.
 //
-// If len(indices) is more than MaxIndicesCount, DrawTriangles panics.
-//
 // The rule in which DrawTriangles works effectively is same as DrawImage's.
 //
 // When the given image is disposed, DrawTriangles panics.
@@ -430,9 +430,6 @@ func (i *Image) DrawTriangles(vertices []Vertex, indices []uint16, img *Image, o
 	if len(indices)%3 != 0 {
 		panic("ebiten: len(indices) % 3 must be 0")
 	}
-	if len(indices) > MaxIndicesCount {
-		panic("ebiten: len(indices) must be <= MaxIndicesCount")
-	}
 	// TODO: Check the maximum value of indices and len(vertices)?
 
 	if options == nil {
@@ -556,8 +553,6 @@ var _ [len(DrawTrianglesShaderOptions{}.Images) - graphics.ShaderImageCount]stru
 //
 // If len(indices) is not multiple of 3, DrawTrianglesShader panics.
 //
-// If len(indices) is more than MaxIndicesCount, DrawTrianglesShader panics.
-//
 // When a specified image is non-nil and is disposed, DrawTrianglesShader panics.
 //
 // When the image i is disposed, DrawTrianglesShader does nothing.
@@ -571,9 +566,6 @@ func (i *Image) DrawTrianglesShader(vertices []Vertex, indices []uint16, shader
 	if len(indices)%3 != 0 {
 		panic("ebiten: len(indices) % 3 must be 0")
 	}
-	if len(indices) > MaxIndicesCount {
-		panic("ebiten: len(indices) must be <= MaxIndicesCount")
-	}
 	// TODO: Check the maximum value of indices and len(vertices)?
 
 	if options == nil {
diff --git a/image_test.go b/image_test.go
index 1101e80ac..6f4f1e28c 100644
--- a/image_test.go
+++ b/image_test.go
@@ -2742,7 +2742,7 @@ func TestIndicesOverflow(t *testing.T) {
 
 	op := &ebiten.DrawTrianglesOptions{}
 	vs := make([]ebiten.Vertex, 3)
-	is := make([]uint16, graphics.IndicesCount/3*3)
+	is := make([]uint16, graphics.MaxVertexCount/3*3)
 	dst.DrawTriangles(vs, is, src, op)
 
 	// Cause an overflow for indices.
@@ -2813,7 +2813,7 @@ func TestVerticesOverflow(t *testing.T) {
 	src.Fill(color.White)
 
 	op := &ebiten.DrawTrianglesOptions{}
-	vs := make([]ebiten.Vertex, graphics.IndicesCount-1)
+	vs := make([]ebiten.Vertex, graphics.MaxVertexCount-1)
 	is := make([]uint16, 3)
 	dst.DrawTriangles(vs, is, src, op)
 
@@ -2885,7 +2885,7 @@ func TestTooManyVertices(t *testing.T) {
 	src.Fill(color.White)
 
 	op := &ebiten.DrawTrianglesOptions{}
-	vs := make([]ebiten.Vertex, graphics.IndicesCount+1)
+	vs := make([]ebiten.Vertex, graphics.MaxVertexCount+1)
 	is := make([]uint16, 3)
 	dst.DrawTriangles(vs, is, src, op)
 
diff --git a/internal/graphics/vertex.go b/internal/graphics/vertex.go
index 00815a57b..7fa2cde87 100644
--- a/internal/graphics/vertex.go
+++ b/internal/graphics/vertex.go
@@ -51,10 +51,6 @@ const (
 		16 // the projection matrix
 )
 
-const (
-	IndicesCount = (1 << 16) / 3 * 3 // Adjust num for triangles. TODO: Remove this (#2460).
-)
-
 const (
 	VertexFloatCount = 8