本文整理汇总了C++中BlockFile::SeekTo方法的典型用法代码示例。如果您正苦于以下问题：C++ BlockFile::SeekTo方法的具体用法？C++ BlockFile::SeekTo怎么用？C++ BlockFile::SeekTo使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类BlockFile的用法示例。
在下文中一共展示了BlockFile::SeekTo方法的5个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: CopyWrite
void WaveTrack::CopyWrite(sampleType * buffer, WaveBlock * b,
sampleCount start, sampleCount len)
{
// Usually we don't write to an existing block; to support Undo,
// we copy the old block entirely into memory, dereference it,
// make the change, and then write the new block to disk.
wxASSERT(b);
wxASSERT(b->len <= maxSamples);
wxASSERT(start + len <= b->len);
dirty++; // forces redraw
sampleType *newBuffer = 0;
newBuffer = new sampleType[maxSamples];
wxASSERT(newBuffer);
Read(newBuffer, b, 0, b->len);
for (int i = 0; i < len; i++)
newBuffer[start + i] = buffer[i];
BlockFile *oldBlockFile = b->f;
b->f = dirManager->NewBlockFile();
bool inited = InitBlock(b);
wxASSERT(inited);
buffer = newBuffer;
start = 0;
len = b->len;
dirManager->Deref(oldBlockFile);
// Write the block
BlockFile *f = b->f;
wxASSERT(f);
bool opened = f->OpenWriting();
wxASSERT(opened);
f->SeekTo(totalHeaderLen + (start * sizeof(sampleType)));
f->Write((void *) buffer, len * sizeof(sampleType));
UpdateSummaries(buffer, b, len);
if (newBuffer)
delete[]newBuffer;
f->Close();
}示例2: wxASSERT
void WaveTrack::Read64K(sampleType * buffer, WaveBlock * b,
sampleCount start, sampleCount len)
{
wxASSERT(b);
wxASSERT(start >= 0);
wxASSERT(start + len <= ((b->len + 65535) / 65536));
start *= 2;
len *= 2;
BlockFile *f = b->f;
bool opened = f->OpenReadHeader();
wxASSERT(opened);
f->SeekTo(headerTagLen + start * sizeof(sampleType));
int result = f->Read((void *) buffer, (int) (len * sizeof(sampleType)));
wxASSERT(result == (int) (len * sizeof(sampleType)));
f->Close();
}示例3: FirstWrite
void WaveTrack::FirstWrite(sampleType * buffer, WaveBlock * b,
sampleCount len)
{
wxASSERT(b);
wxASSERT(b->len <= maxSamples);
dirty++; // forces redraw
BlockFile *f = b->f;
wxASSERT(f);
bool opened = f->OpenWriting();
wxASSERT(opened);
f->SeekTo(totalHeaderLen);
f->Write((void *) buffer, len * sizeof(sampleType));
UpdateSummaries(buffer, b, len);
f->Close();
}示例4: Read
void WaveTrack::Read(sampleType * buffer, WaveBlock * b,
sampleCount start, sampleCount len)
{
wxASSERT(b);
wxASSERT(start >= 0);
wxASSERT(start + len <= b->len);
BlockFile *f = b->f;
bool opened = f->OpenReadData();
wxASSERT(opened);
f->SeekTo(totalHeaderLen + (start * sizeof(sampleType)));
int result = f->Read((void *) buffer, (int) (len * sizeof(sampleType)));
if (result != (int) (len * sizeof(sampleType))) {
printf("Expected to read %d bytes, got %d bytes.\n",
len * sizeof(sampleType), result);
}
wxASSERT(result == (int) (len * sizeof(sampleType)));
f->Close();
}示例5: UpdateSummaries
void WaveTrack::UpdateSummaries(sampleType * buffer,
WaveBlock * b, sampleCount len)
{
// This method assumes that b->f is already opened
BlockFile *f = b->f;
sampleType *summary64K = new sampleType[summary64KLen];
sampleType *summary256 = new sampleType[summary256Len];
sampleCount sumLen;
sampleCount i, j, jcount;
sampleType min, max;
// Recalc 256 summaries
sumLen = (len + 255) / 256;
for (i = 0; i < sumLen; i++) {
min = buffer[i * 256];
max = buffer[i * 256];
jcount = 256;
if (i * 256 + jcount > len)
jcount = len - i * 256;
for (j = 1; j < jcount; j++) {
if (buffer[i * 256 + j] < min)
min = buffer[i * 256 + j];
else if (buffer[i * 256 + j] > max)
max = buffer[i * 256 + j];
}
summary256[i * 2] = min;
summary256[i * 2 + 1] = max;
}
for (i = sumLen; i < summary256Len / 2; i++) {
summary256[i * 2] = 0;
summary256[i * 2 + 1] = 0;
}
// Recalc 64K summaries
sumLen = (len + 65535) / 65536;
for (i = 0; i < sumLen; i++) {
min = summary256[2 * i * 256];
max = summary256[2 * i * 256 + 1];
for (j = 1; j < 256; j++) {
if (summary256[2 * (i * 256 + j)] < min)
min = summary256[2 * (i * 256 + j)];
if (summary256[2 * (i * 256 + j) + 1] > max)
max = summary256[2 * (i * 256 + j) + 1];
}
summary64K[i * 2] = min;
summary64K[i * 2 + 1] = max;
}
for (i = sumLen; i < summary64KLen / 2; i++) {
summary256[i * 2] = 0;
summary256[i * 2 + 1] = 0;
}
// Recalc block-level summary
min = summary64K[0];
max = summary64K[1];
for (i = 1; i < sumLen; i++) {
if (summary64K[2*i] < min)
min = summary64K[2*i];
else if (summary64K[2*i+1] > max)
max = summary64K[2*i+1];
}
b->min = min;
b->max = max;
// Write 256 and 64K summaries to disk
f->SeekTo(headerTagLen);
f->Write((void *) summary64K, summary64KLen * sizeof(sampleType));
f->Write((void *) summary256, summary256Len * sizeof(sampleType));
delete[]summary64K;
delete[]summary256;
}