From 4603ca037cab2d0f732285ce9e006744ad3118d6 Mon Sep 17 00:00:00 2001
From: John Firebaugh <john.firebaugh@gmail.com>
Date: Tue, 26 Aug 2014 15:24:16 -0700
Subject: background-image support

---
 src/util/mat3.cpp | 46 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 45 insertions(+), 1 deletion(-)

(limited to 'src/util')

diff --git a/src/util/mat3.cpp b/src/util/mat3.cpp
index 38858d2385..263768ee41 100644
--- a/src/util/mat3.cpp
+++ b/src/util/mat3.cpp
@@ -38,7 +38,51 @@ void matrix::identity(mat3& out) {
     out[8] = 1.0f;
 }
 
-void matrix::scale(mat3& out, const mat3& a, const float x, const float y) {
+void matrix::translate(mat3& out, const mat3& a, float x, float y) {
+    float a00 = a[0], a01 = a[1], a02 = a[2],
+          a10 = a[3], a11 = a[4], a12 = a[5],
+          a20 = a[6], a21 = a[7], a22 = a[8];
+
+    out[0] = a00;
+    out[1] = a01;
+    out[2] = a02;
+
+    out[3] = a10;
+    out[4] = a11;
+    out[5] = a12;
+
+    out[6] = x * a00 + y * a10 + a20;
+    out[7] = x * a01 + y * a11 + a21;
+    out[8] = x * a02 + y * a12 + a22;
+}
+
+void matrix::rotate(mat3& out, const mat3& a, float rad) {
+    float s = std::sin(rad),
+          c = std::cos(rad),
+          a00 = a[0],
+          a01 = a[1],
+          a02 = a[2],
+          a10 = a[3],
+          a11 = a[4],
+          a12 = a[5],
+          a20 = a[6],
+          a21 = a[7],
+          a22 = a[8];
+
+    out[0] = c * a00 + s * a10;
+    out[1] = c * a01 + s * a11;
+    out[2] = c * a02 + s * a12;
+
+    out[3] = c * a10 - s * a00;
+    out[4] = c * a11 - s * a01;
+    out[5] = c * a12 - s * a02;
+
+    out[6] = a20;
+    out[7] = a21;
+    out[8] = a22;
+};
+
+void matrix::scale(mat3& out, const mat3& a, float x, float y) {
     out[0] = x * a[0];
     out[1] = x * a[1];
     out[2] = x * a[2];
-- 
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