From 8860d315ca57218bc2d45292210e14a0f1cec5bc Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@hajimehoshi.com>
Date: Sun, 23 Jun 2013 23:43:44 +0900
Subject: [PATCH] Add Monochrome

---
 example/game/monochrome/monochrome.go | 60 +++++++++++++++++++++++++++
 example/glut/main.go                  |  3 ++
 graphics/matrix/color.go              | 14 +++++++
 graphics/opengl/graphics_context.go   |  8 ++--
 4 files changed, 81 insertions(+), 4 deletions(-)
 create mode 100644 example/game/monochrome/monochrome.go

diff --git a/example/game/monochrome/monochrome.go b/example/game/monochrome/monochrome.go
new file mode 100644
index 000000000..d20506e40
--- /dev/null
+++ b/example/game/monochrome/monochrome.go
@@ -0,0 +1,60 @@
+package monochrome
+
+import (
+	"github.com/hajimehoshi/go.ebiten/graphics"
+	"github.com/hajimehoshi/go.ebiten/graphics/matrix"
+	"image"
+	"image/color"
+	_ "image/png"
+	"os"
+)
+
+type Monochrome struct {
+	ebitenTexture graphics.Texture
+}
+
+func New() *Monochrome {
+	return &Monochrome{}
+}
+
+func (game *Monochrome) ScreenWidth() int {
+	return 256
+}
+
+func (game *Monochrome) ScreenHeight() int {
+	return 240
+}
+
+func (game *Monochrome) Fps() int {
+	return 60
+}
+
+func (game *Monochrome) Init(tf graphics.TextureFactory) {
+	file, err := os.Open("ebiten.png")
+	if err != nil {
+		panic(err)
+	}
+	defer file.Close()
+
+	img, _, err := image.Decode(file)
+	if err != nil {
+		panic(err)
+	}
+	if game.ebitenTexture, err = tf.NewTextureFromImage(img); err != nil {
+		panic(err)
+	}
+}
+
+func (game *Monochrome) Update() {
+}
+
+func (game *Monochrome) Draw(g graphics.GraphicsContext, offscreen graphics.Texture) {
+	g.Fill(&color.RGBA{R: 128, G: 128, B: 255, A: 255})
+
+	geometryMatrix := matrix.IdentityGeometry()
+	tx := game.ScreenWidth() / 2 - game.ebitenTexture.Width / 2
+	ty := game.ScreenHeight() / 2 - game.ebitenTexture.Height / 2
+	geometryMatrix.Translate(float64(tx), float64(ty))
+	g.DrawTexture(game.ebitenTexture.ID,
+		geometryMatrix, matrix.Monochrome())
+}
diff --git a/example/glut/main.go b/example/glut/main.go
index 55a3a386e..3bf71146e 100644
--- a/example/glut/main.go
+++ b/example/glut/main.go
@@ -18,6 +18,7 @@ package main
 import "C"
 import (
 	"github.com/hajimehoshi/go.ebiten"
+	"github.com/hajimehoshi/go.ebiten/example/game/monochrome"
 	"github.com/hajimehoshi/go.ebiten/example/game/rects"
 	"github.com/hajimehoshi/go.ebiten/example/game/rotating"
 	"github.com/hajimehoshi/go.ebiten/example/game/sprites"
@@ -89,6 +90,8 @@ func main() {
 
 	var gm ebiten.Game
 	switch gameName {
+	case "monochrome":
+		gm = monochrome.New()
 	case "rects":
 		gm = rects.New()
 	case "rotating":
diff --git a/graphics/matrix/color.go b/graphics/matrix/color.go
index 5e4bc85b6..4cc4c28ed 100644
--- a/graphics/matrix/color.go
+++ b/graphics/matrix/color.go
@@ -38,3 +38,17 @@ func (matrix *Color) element(i, j int) float64 {
 func (matrix *Color) setElement(i, j int, element float64) {
 	matrix.Elements[i][j] = element
 }
+
+func Monochrome() Color {
+	const r float64 = 6968.0 / 32768.0
+	const g float64 = 23434.0 / 32768.0
+	const b float64 = 2366.0 / 32768.0
+	return Color{
+		[colorDim - 1][colorDim]float64{
+			{r, g, b, 0, 0},
+			{r, g, b, 0, 0},
+			{r, g, b, 0, 0},
+			{0, 0, 0, 1, 0},
+		},
+	}
+}
diff --git a/graphics/opengl/graphics_context.go b/graphics/opengl/graphics_context.go
index 906342863..16acb78b5 100644
--- a/graphics/opengl/graphics_context.go
+++ b/graphics/opengl/graphics_context.go
@@ -293,10 +293,10 @@ func (context *GraphicsContext) setShaderProgram(
 	}
 
 	glColorMatrix := [...]float32{
-		e[0][0], e[0][1], e[0][2], e[0][3],
-		e[1][0], e[1][1], e[1][2], e[1][3],
-		e[2][0], e[2][1], e[2][2], e[2][3],
-		e[3][0], e[3][1], e[3][2], e[3][3],
+		e[0][0], e[1][0], e[2][0], e[3][0],
+		e[0][1], e[1][1], e[2][1], e[3][1],
+		e[0][2], e[1][2], e[2][2], e[3][2],
+		e[0][3], e[1][3], e[2][3], e[3][3],
 	}
 	C.glUniformMatrix4fv(getUniformLocation(program, "color_matrix"),
 		1, C.GL_FALSE, (*C.GLfloat)(&glColorMatrix[0]))