Aegisub/aegisub/src/audio_renderer.cpp

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// Copyright (c) 2009, Niels Martin Hansen
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of the Aegisub Group nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Aegisub Project http://www.aegisub.org/
//
// $Id$
/// @file audio_renderer.cpp
/// @brief Base classes for audio renderers (spectrum, waveform, ...)
/// @ingroup audio_ui
#include "audio_renderer.h"
#include <wx/bitmap.h>
#include <map>
/// @class AudioRendererBitmapCache
/// @brief Caches bitmaps of rendered audio at a specific resolution
///
/// Used internally by the AudioRenderer class.
class AudioRendererBitmapCache {
/// Width of cached bitmaps
int width;
/// Height of cached bitmaps
int height;
/// Memory size of each cached image, for cache management
size_t bytes_per_image;
// Cached bitmaps
// Intentionally not doxygened, too internal
struct CachedBitmap {
// The bitmap itself
wxBitmap bmp;
// "Timestamp" of last access (not necessarily related to any clocks)
int last_access;
CachedBitmap(wxBitmap bmp = wxBitmap()) : bmp(bmp), last_access(0) { }
~CachedBitmap() { }
bool operator < (const CachedBitmap &other) const { return last_access < other.last_access; }
};
typedef std::map<int, CachedBitmap> CacheType;
CacheType cache;
public:
/// @brief Constructor
///
/// Does nothing.
AudioRendererBitmapCache();
/// @brief Destructor
///
/// Does nothing.
~AudioRendererBitmapCache();
/// @brief Age the cache, purging old items
/// @param max_size Maximum allowed cache size, in bytes
///
/// Purges the least recently used bitmaps to bring the cache size below max_size.
/// Aging is a somewhat expensive operation and should only be done once in a while.
///
/// If max_size is specified to 0, the cache will be entirely cleared in a fast manner.
void Age(size_t max_size);
/// @brief Change the size of cached images
/// @param new_width New width of images to cache
/// @param new_height New height of images to cache
///
/// Clears and re-initialises the cache.
void Resize(int new_width, int new_height);
/// @brief Retrieve an image from cache
/// @param bmp [out] Bitmap to return the image in
/// @param key Key to request the image for
/// @param timestamp Timestamp to use for cache age management
/// @return Returns false if the image had to be created in cache; if the return is
/// false, the consumer must draw into the returned bitmap.
///
/// Example:
/// @code
/// wxBitmap bmp;
/// if (!cache->Get(bmp, key, timestamp))
/// RenderBitmap(bmp);
/// // Use bmp
/// @endcode
///
/// The timestamp passed should never decrease between calls to the same cache.
///
/// The key has no inherent meaning to the cache.
bool Get(wxBitmap &bmp, int key, int timestamp);
};
AudioRendererBitmapCache::AudioRendererBitmapCache()
{
Resize(0, 0);
}
AudioRendererBitmapCache::~AudioRendererBitmapCache()
{
// Nothing to do
}
void AudioRendererBitmapCache::Age(size_t max_size)
{
if (max_size == 0)
{
cache.clear();
return;
}
/// @todo Make this faster than O(n^2)
size_t max_items = max_size / bytes_per_image;
while (cache.size() > max_items)
{
// Find the oldest item and remove it
CacheType::iterator next = cache.begin();
CacheType::iterator oldest = next;
while (++next != cache.end())
{
if (next->second.last_access < oldest->second.last_access)
oldest = next;
}
cache.erase(oldest);
}
}
void AudioRendererBitmapCache::Resize(int new_width, int new_height)
{
Age(0);
width = new_width;
height = new_height;
// Assuming 32 bpp
// This probably isn't completely accurate, but just a reasonable approximation
bytes_per_image = sizeof(CachedBitmap) + width*height*4;
}
bool AudioRendererBitmapCache::Get(wxBitmap &bmp, int key, int timestamp)
{
CacheType::iterator item = cache.find(key);
bool found = true;
if (item == cache.end())
{
cache[key] = CachedBitmap(wxBitmap(width, height, 32));
item = cache.find(key);
assert(item != cache.end());
found = false;
}
item->second.last_access = timestamp;
bmp = item->second.bmp;
return found;
}
AudioRenderer::AudioRenderer()
: cache_bitmap_width(32) // arbitrary value for now
, bitmaps_normal(new AudioRendererBitmapCache)
, bitmaps_selected(new AudioRendererBitmapCache)
, cache_clock(0)
, cache_maxsize(0)
, renderer(0)
, provider(0)
{
// Make sure there's *some* values for those fields, and in the caches
SetSamplesPerPixel(1);
SetHeight(1);
}
AudioRenderer::~AudioRenderer()
{
// Nothing to do, everything is auto-allocated
}
void AudioRenderer::SetSamplesPerPixel(int _pixel_samples)
{
pixel_samples = _pixel_samples;
}
void AudioRenderer::SetHeight(int _pixel_height)
{
if (pixel_height == _pixel_height) return;
pixel_height = _pixel_height;
bitmaps_normal->Resize(cache_bitmap_width, pixel_height);
bitmaps_selected->Resize(cache_bitmap_width, pixel_height);
}
void AudioRenderer::SetRenderer(AudioRendererBitmapProvider *_renderer)
{
if (renderer == _renderer) return;
if (renderer)
renderer->SetProvider(0);
renderer = _renderer;
bitmaps_normal->Age(0);
bitmaps_selected->Age(0);
if (renderer)
renderer->SetProvider(provider);
}
void AudioRenderer::SetAudioProvider(AudioProvider *_provider)
{
if (provider == _provider) return;
provider = _provider;
bitmaps_normal->Age(0);
bitmaps_selected->Age(0);
if (renderer)
renderer->SetProvider(provider);
}
wxBitmap AudioRenderer::GetCachedBitmap(int i, bool selected)
{
assert(provider);
assert(renderer);
// Pick the cache to use
AudioRendererBitmapCache *cache = (selected ? bitmaps_selected : bitmaps_normal).get();
wxBitmap bmp;
if (!cache->Get(bmp, i, cache_clock))
{
renderer->Render(bmp, i*cache_bitmap_width, selected);
}
assert(bmp.IsOk());
return bmp;
}
void AudioRenderer::Render(wxDC &dc, wxPoint origin, int start, int length, bool selected)
{
assert(start >= 0);
assert(length >= 0);
assert(start >= 0);
if (!provider) return;
if (!renderer) return;
// Last absolute pixel strip to render
int end = start + length - 1;
// Figure out which range of bitmaps are required
int firstbitmap = start / cache_bitmap_width;
// And the offset in it to start its use at
int firstbitmapoffset = start % cache_bitmap_width;
// The last bitmap required
int lastbitmap = end / cache_bitmap_width;
// How many columns of the last bitmap to use
int lastbitmapoffset = end % cache_bitmap_width;
// Two basic cases now: Either firstbitmap is the same as lastbitmap, or they're different.
// origin is passed by value because we'll be using it as a local var to keep track
// of rendering progress!
if (firstbitmap == lastbitmap)
{
// These better be the same: The first to the last column of the single bitmap
// to use should equal the length of the area to render.
assert(lastbitmapoffset - firstbitmapoffset == length);
wxBitmap bmp = GetCachedBitmap(firstbitmap, selected);
wxMemoryDC bmpdc(bmp);
dc.Blit(origin, wxSize(length, pixel_height), &bmpdc, wxPoint(firstbitmapoffset, 0));
}
else
{
wxBitmap bmp;
{
bmp = GetCachedBitmap(firstbitmap, selected);
wxMemoryDC bmpdc(bmp);
dc.Blit(origin, wxSize(cache_bitmap_width-firstbitmapoffset, pixel_height),
&bmpdc, wxPoint(firstbitmapoffset, 0));
origin.x += cache_bitmap_width-firstbitmapoffset;
}
for (int i = 1; i < lastbitmap; ++i)
{
bmp = GetCachedBitmap(i, selected);
wxMemoryDC bmpdc(bmp);
dc.Blit(origin, wxSize(cache_bitmap_width, pixel_height), &bmpdc, wxPoint(0, 0));
origin.x += cache_bitmap_width;
}
{
bmp = GetCachedBitmap(lastbitmap, selected);
wxMemoryDC bmpdc(bmp);
dc.Blit(origin, wxSize(lastbitmapoffset, pixel_height), &bmpdc, wxPoint(0, 0));
}
}
if (selected)
bitmaps_selected->Age(cache_maxsize);
else
bitmaps_normal->Age(cache_maxsize);
}