iOS Chromoting Client

remoting/ios/ui/cursor_texture.mm

+// Copyright 2014 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.
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+#import "remoting/ios/ui/cursor_texture.h"
+
+@implementation CursorTexture
+
+- (id)init {
+  self = [super init];
+  if (self) {
+    _needCursorRedraw = NO;
+    _cursorDrawnToGL = webrtc::DesktopRect::MakeXYWH(0, 0, 0, 0);
+  }
+  return self;
+}
+
+- (const webrtc::DesktopSize&)textureSize {
+  return _textureSize;
+}
+
+- (void)setTextureSize:(const webrtc::DesktopSize&)size {
+  if (!_textureSize.equals(size)) {
+    _textureSize.set(size.width(), size.height());
+    _needInitialize = true;
+  }
+}
+
+- (const webrtc::MouseCursor&)cursor {
+  return *_cursor.get();
+}
+
+- (void)setCursor:(webrtc::MouseCursor*)cursor {
+  _cursor.reset(cursor);
+
+  if (_cursor.get() != NULL && _cursor->image().data()) {
+    _needCursorRedraw = true;
+  }
+}
+
+- (void)bindToEffect:(GLKEffectPropertyTexture*)effectProperty {
+  glGenTextures(1, &_textureId);
+  [Utility bindTextureForIOS:_textureId];
+
+  // This is the Cursor layer, and is stamped on top of Desktop as a
+  // transparent image
+  effectProperty.target = GLKTextureTarget2D;
+  effectProperty.name = _textureId;
+  effectProperty.envMode = GLKTextureEnvModeDecal;
+  effectProperty.enabled = GL_TRUE;
+
+  [Utility logGLErrorCode:@"CursorTexture bindToTexture"];
+  // Release context
+  glBindTexture(GL_TEXTURE_2D, 0);
+}
+
+- (BOOL)needDrawAtPosition:(const webrtc::DesktopVector&)position {
+  return (_cursor.get() != NULL &&
+          (_needInitialize || _needCursorRedraw == YES ||
+           _cursorDrawnToGL.left() != position.x() - _cursor->hotspot().x() ||
+           _cursorDrawnToGL.top() != position.y() - _cursor->hotspot().y()));
+}
+
+- (void)drawWithMousePosition:(const webrtc::DesktopVector&)position {
+  if (_textureSize.height() == 0 && _textureSize.width() == 0) {
+    return;
+  }
+
+  [Utility bindTextureForIOS:_textureId];
+
+  if (_needInitialize) {
+    glTexImage2D(GL_TEXTURE_2D,
+                 0,
+                 GL_RGBA,
+                 _textureSize.width(),
+                 _textureSize.height(),
+                 0,
+                 GL_RGBA,
+                 GL_UNSIGNED_BYTE,
+                 NULL);
+
+    [Utility logGLErrorCode:@"CursorTexture initializeTextureSurfaceWithSize"];
+    _needInitialize = false;
+  }
+  // When the cursor needs to be redraw in a different spot then we must clear
+  // the previous area.
+
+  DCHECK([self needDrawAtPosition:position]);
+
+  if (_cursorDrawnToGL.width() > 0 && _cursorDrawnToGL.height() > 0) {
+    webrtc::BasicDesktopFrame transparentCursor(_cursorDrawnToGL.size());
+
+    if (transparentCursor.data() != NULL) {
+      DCHECK(transparentCursor.kBytesPerPixel ==
+             _cursor->image().kBytesPerPixel);
+      memset(transparentCursor.data(),
+             0,
+             transparentCursor.stride() * transparentCursor.size().height());
+
+      [Utility drawSubRectToGLFromRectOfSize:_textureSize
+                                     subRect:_cursorDrawnToGL
+                                        data:transparentCursor.data()];
+
+      // there is no longer any cursor drawn to screen
+      _cursorDrawnToGL = webrtc::DesktopRect::MakeXYWH(0, 0, 0, 0);
+    }
+  }
+
+  if (_cursor.get() != NULL) {
+
+    CGRect screen =
+        CGRectMake(0.0, 0.0, _textureSize.width(), _textureSize.height());
+    CGRect cursor = CGRectMake(position.x() - _cursor->hotspot().x(),
+                               position.y() - _cursor->hotspot().y(),
+                               _cursor->image().size().width(),
+                               _cursor->image().size().height());
+
+    if (CGRectContainsRect(screen, cursor)) {
+      _cursorDrawnToGL = webrtc::DesktopRect::MakeXYWH(cursor.origin.x,
+                                                       cursor.origin.y,
+                                                       cursor.size.width,
+                                                       cursor.size.height);
+
+      [Utility drawSubRectToGLFromRectOfSize:_textureSize
+                                     subRect:_cursorDrawnToGL
+                                        data:_cursor->image().data()];
+
+    } else if (CGRectIntersectsRect(screen, cursor)) {
+      // Some of the cursor falls off screen, need to clip it
+      CGRect intersection = CGRectIntersection(screen, cursor);
+      _cursorDrawnToGL =
+          webrtc::DesktopRect::MakeXYWH(intersection.origin.x,
+                                        intersection.origin.y,
+                                        intersection.size.width,
+                                        intersection.size.height);
+
+      webrtc::BasicDesktopFrame partialCursor(_cursorDrawnToGL.size());
+
+      if (partialCursor.data()) {
+        DCHECK(partialCursor.kBytesPerPixel == _cursor->image().kBytesPerPixel);
+
+        uint32_t src_stride = _cursor->image().stride();
+        uint32_t dst_stride = partialCursor.stride();
+
+        uint8_t* source = _cursor->image().data();
+        source += abs((static_cast<int32_t>(cursor.origin.y) -
+                       _cursorDrawnToGL.top())) *
+                  src_stride;
+        source += abs((static_cast<int32_t>(cursor.origin.x) -
+                       _cursorDrawnToGL.left())) *
+                  _cursor->image().kBytesPerPixel;
+        uint8_t* dst = partialCursor.data();
+
+        for (uint32_t y = 0; y < _cursorDrawnToGL.height(); y++) {
+          memcpy(dst, source, dst_stride);
+          source += src_stride;
+          dst += dst_stride;
+        }
+
+        [Utility drawSubRectToGLFromRectOfSize:_textureSize
+                                       subRect:_cursorDrawnToGL
+                                          data:partialCursor.data()];
+      }
+    }
+  }
+
+  _needCursorRedraw = false;
+  [Utility logGLErrorCode:@"CursorTexture drawWithMousePosition"];
+  // Release context
+  glBindTexture(GL_TEXTURE_2D, 0);
+}
+
+- (void)releaseTexture {
+  glDeleteTextures(1, &_textureId);
+}
+
+@end