From 9748b28c0ef471a8c1b3811a4bb40cb3ee46c366 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sat, 11 Feb 2017 03:44:29 +0900
Subject: [PATCH] graphics: Try to make CI happy

---
 image_test.go     |  2 +-
 vertices.go       | 21 +++++++++++++++++++++
 vertices_js.go    |  4 ++--
 vertices_notjs.go |  4 ++--
 4 files changed, 26 insertions(+), 5 deletions(-)
 create mode 100644 vertices.go

diff --git a/image_test.go b/image_test.go
index 6c95e5c5d..8053e4563 100644
--- a/image_test.go
+++ b/image_test.go
@@ -642,7 +642,7 @@ func TestImageEdge(t *testing.T) {
 				if c == transparent {
 					continue
 				}
-				t.Errorf("img1.At(%d, %d) want: red or transparent, got: %v", i, j, c)
+				t.Errorf("img1.At(%d, %d) (angle: %d) want: red or transparent, got: %v", i, j, a, c)
 			}
 		}
 	}
diff --git a/vertices.go b/vertices.go
new file mode 100644
index 000000000..d933407f9
--- /dev/null
+++ b/vertices.go
@@ -0,0 +1,21 @@
+// Copyright 2017 The Ebiten Authors
+//
+// 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 ebiten
+
+// texelAdjustment represents a number to be used to adjust texel.
+// Texels are adjusted by amount propotional to inverse of texelAdjustment.
+// This is necessary not to use unexpected pixels outside of texels.
+// See #317.
+const texelAdjustment = 128
diff --git a/vertices_js.go b/vertices_js.go
index 350f633f7..0df8349d0 100644
--- a/vertices_js.go
+++ b/vertices_js.go
@@ -57,8 +57,8 @@ func vertices(parts ImageParts, width, height int, geo *affine.GeoM) []float32 {
 		}
 		u0, v0, u1, v1 := float64(sx0)/wf, float64(sy0)/hf, float64(sx1)/wf, float64(sy1)/hf
 		// Adjust texels to fix a problem that outside texels are used (#317).
-		u1 -= 1.0 / wf / 256.0
-		v1 -= 1.0 / hf / 256.0
+		u1 -= 1.0 / wf / texelAdjustment
+		v1 -= 1.0 / hf / texelAdjustment
 		vs.SetIndex(n, dx0)
 		vs.SetIndex(n+1, dy0)
 		vs.SetIndex(n+2, u0)
diff --git a/vertices_notjs.go b/vertices_notjs.go
index 4393643b0..47b866a31 100644
--- a/vertices_notjs.go
+++ b/vertices_notjs.go
@@ -56,8 +56,8 @@ func vertices(parts ImageParts, width, height int, geo *affine.GeoM) []float32 {
 		}
 		u0, v0, u1, v1 := float32(sx0)/wf, float32(sy0)/hf, float32(sx1)/wf, float32(sy1)/hf
 		// Adjust texels to fix a problem that outside texels are used (#317).
-		u1 -= 1.0 / wf / 256.0
-		v1 -= 1.0 / hf / 256.0
+		u1 -= 1.0 / wf / texelAdjustment
+		v1 -= 1.0 / hf / texelAdjustment
 		vs[n] = x0
 		vs[n+1] = y0
 		vs[n+2] = u0