[Remoting Android] Cursor & Cursor Feedback for OpenGL Renderer

remoting/client/gl_math.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "remoting/client/gl_math.h"
+
+#include <sstream>
+
+namespace {
+
+// | m0, m1, m2, |   | Scale_x  0        Offset_x |
+// | m3, m4, m5, | = | 0        Scale_y  Offset_y |
+// | m6, m7, m8  |   | 0        0        1        |
+
+const int kXScaleKey = 0;
+const int kYScaleKey = 4;
+const int kXOffsetKey = 2;
+const int kYOffsetKey = 5;
+
+}  // namespace
+
+namespace remoting {
+
+void NormalizeTransformationMatrix(int view_width,
+                                   int view_height,
+                                   int canvas_width,
+                                   int canvas_height,
+                                   std::array<float, 9>* matrix) {
+  (*matrix)[kXScaleKey] = canvas_width * (*matrix)[kXScaleKey] / view_width;
+  (*matrix)[kYScaleKey] = canvas_height * (*matrix)[kYScaleKey] / view_height;
+  (*matrix)[kXOffsetKey] /= view_width;
+  (*matrix)[kYOffsetKey] /= view_height;
+}
+
+void FillRectangleVertexPositions(float left,
+                                  float top,
+                                  float width,
+                                  float height,
+                                  std::array<float, 8>* positions) {
+  (*positions)[0] = left;
+  (*positions)[1] = top;
+
+  (*positions)[2] = left;
+  (*positions)[3] = top + height;
+
+  (*positions)[4] = left + width;
+  (*positions)[5] = top;
+
+  (*positions)[6] = left + width;
+  (*positions)[7] = top + height;
+}
+
+std::string MatrixToString(const float* mat, int num_rows, int num_cols) {
+  std::ostringstream outstream;
+  outstream << "[\n";
+  for (int i = 0; i < num_rows; i++) {
+    for (int j = 0; j < num_cols; j++) {
+      outstream << mat[i * num_cols + j] << ", ";
+    }
+    outstream << "\n";
+  }
+  outstream << "]";
+  return outstream.str();
+}
+
+}  // namespace remoting