1 files changed, 158 insertions, 0 deletions
diff --git a/dom/canvas/WebGL2ContextBuffers.cpp b/dom/canvas/WebGL2ContextBuffers.cpp
new file mode 100644
index 000000000..f59fa08b8
--- /dev/null
+++ b/dom/canvas/WebGL2ContextBuffers.cpp
@@ -0,0 +1,158 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "WebGL2Context.h"
+
+#include "GLContext.h"
+#include "WebGLBuffer.h"
+#include "WebGLTransformFeedback.h"
+
+namespace mozilla {
+
+// -------------------------------------------------------------------------
+// Buffer objects
+
+void
+WebGL2Context::CopyBufferSubData(GLenum readTarget, GLenum writeTarget,
+                                 GLintptr readOffset, GLintptr writeOffset,
+                                 GLsizeiptr size)
+{
+    const char funcName[] = "copyBufferSubData";
+    if (IsContextLost())
+        return;
+
+    const auto& readBuffer = ValidateBufferSelection(funcName, readTarget);
+    if (!readBuffer)
+        return;
+
+    const auto& writeBuffer = ValidateBufferSelection(funcName, writeTarget);
+    if (!writeBuffer)
+        return;
+
+    if (!ValidateNonNegative(funcName, "readOffset", readOffset) ||
+        !ValidateNonNegative(funcName, "writeOffset", writeOffset) ||
+        !ValidateNonNegative(funcName, "size", size))
+    {
+        return;
+    }
+
+    const auto fnValidateOffsetSize = [&](const char* info, GLintptr offset,
+                                          const WebGLBuffer* buffer)
+    {
+        const auto neededBytes = CheckedInt<size_t>(offset) + size;
+        if (!neededBytes.isValid() || neededBytes.value() > buffer->ByteLength()) {
+            ErrorInvalidValue("%s: Invalid %s range.", funcName, info);
+            return false;
+        }
+        return true;
+    };
+
+    if (!fnValidateOffsetSize("read", readOffset, readBuffer) ||
+        !fnValidateOffsetSize("write", writeOffset, writeBuffer))
+    {
+        return;
+    }
+
+    if (readBuffer == writeBuffer) {
+        MOZ_ASSERT((CheckedInt<WebGLsizeiptr>(readOffset) + size).isValid());
+        MOZ_ASSERT((CheckedInt<WebGLsizeiptr>(writeOffset) + size).isValid());
+
+        const bool separate = (readOffset + size <= writeOffset ||
+                               writeOffset + size <= readOffset);
+        if (!separate) {
+            ErrorInvalidValue("%s: ranges [readOffset, readOffset + size) and"
+                              " [writeOffset, writeOffset + size) overlap",
+                              funcName);
+            return;
+        }
+    }
+
+    const auto& readType = readBuffer->Content();
+    const auto& writeType = writeBuffer->Content();
+    MOZ_ASSERT(readType != WebGLBuffer::Kind::Undefined);
+    MOZ_ASSERT(writeType != WebGLBuffer::Kind::Undefined);
+    if (writeType != readType) {
+        ErrorInvalidOperation("%s: Can't copy %s data to %s data.",
+                              funcName,
+                              (readType == WebGLBuffer::Kind::OtherData) ? "other"
+                                                                         : "element",
+                              (writeType == WebGLBuffer::Kind::OtherData) ? "other"
+                                                                          : "element");
+        return;
+    }
+
+    gl->MakeCurrent();
+    const ScopedLazyBind readBind(gl, readTarget, readBuffer);
+    const ScopedLazyBind writeBind(gl, writeTarget, writeBuffer);
+    gl->fCopyBufferSubData(readTarget, writeTarget, readOffset, writeOffset, size);
+}
+
+void
+WebGL2Context::GetBufferSubData(GLenum target, GLintptr srcByteOffset,
+                                const dom::ArrayBufferView& dstData, GLuint dstElemOffset,
+                                GLuint dstElemCountOverride)
+{
+    const char funcName[] = "getBufferSubData";
+    if (IsContextLost())
+        return;
+
+    if (!ValidateNonNegative(funcName, "srcByteOffset", srcByteOffset))
+        return;
+
+    uint8_t* bytes;
+    size_t byteLen;
+    if (!ValidateArrayBufferView(funcName, dstData, dstElemOffset, dstElemCountOverride,
+                                 &bytes, &byteLen))
+    {
+        return;
+    }
+
+    ////
+
+    const auto& buffer = ValidateBufferSelection(funcName, target);
+    if (!buffer)
+        return;
+
+    if (!buffer->ValidateRange(funcName, srcByteOffset, byteLen))
+        return;
+
+    ////
+
+    if (!CheckedInt<GLsizeiptr>(byteLen).isValid()) {
+        ErrorOutOfMemory("%s: Size too large.", funcName);
+        return;
+    }
+    const GLsizeiptr glByteLen(byteLen);
+
+    ////
+
+    gl->MakeCurrent();
+    const ScopedLazyBind readBind(gl, target, buffer);
+
+    if (byteLen) {
+        const bool isTF = (target == LOCAL_GL_TRANSFORM_FEEDBACK_BUFFER);
+        GLenum mapTarget = target;
+        if (isTF) {
+            gl->fBindTransformFeedback(LOCAL_GL_TRANSFORM_FEEDBACK, mEmptyTFO);
+            gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, buffer->mGLName);
+            mapTarget = LOCAL_GL_ARRAY_BUFFER;
+        }
+
+        const auto mappedBytes = gl->fMapBufferRange(mapTarget, srcByteOffset, glByteLen,
+                                                     LOCAL_GL_MAP_READ_BIT);
+        memcpy(bytes, mappedBytes, byteLen);
+        gl->fUnmapBuffer(mapTarget);
+
+        if (isTF) {
+            const GLuint vbo = (mBoundArrayBuffer ? mBoundArrayBuffer->mGLName : 0);
+            gl->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, vbo);
+            const GLuint tfo = (mBoundTransformFeedback ? mBoundTransformFeedback->mGLName
+                                                        : 0);
+            gl->fBindTransformFeedback(LOCAL_GL_TRANSFORM_FEEDBACK, tfo);
+        }
+    }
+}
+
+} // namespace mozilla