Aegisub/src/audio_renderer.h
2014-07-10 11:44:56 -07:00

290 lines
11 KiB
C++

// Copyright (c) 2009-2010, 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/
#pragma once
#include <memory>
#include <vector>
#include <wx/gdicmn.h>
#include "audio_rendering_style.h"
#include "block_cache.h"
class AudioRenderer;
class AudioRendererBitmapProvider;
class wxDC;
namespace agi { class AudioProvider; }
/// @class AudioRendererBitmapCacheBitmapFactory
/// @brief Produces wxBitmap objects for DataBlockCache storage for the audio renderer
struct AudioRendererBitmapCacheBitmapFactory {
typedef std::unique_ptr<wxBitmap> BlockType;
/// The audio renderer we're producing bitmaps for
AudioRenderer *renderer;
/// @brief Constructor
/// @param renderer The audio renderer to produce bitmaps for
AudioRendererBitmapCacheBitmapFactory(AudioRenderer *renderer);
/// @brief Create a new bitmap
/// @param i Unused
/// @return A fresh wxBitmap
///
/// Produces a wxBitmap with dimensions pulled from our master AudioRenderer.
std::unique_ptr<wxBitmap> ProduceBlock(int i);
/// @brief Calculate the size of bitmaps
/// @return The size of bitmaps created
size_t GetBlockSize() const;
};
/// The type of a bitmap cache
typedef DataBlockCache<wxBitmap, 8, AudioRendererBitmapCacheBitmapFactory> AudioRendererBitmapCache;
/// @class AudioRenderer
/// @brief Renders audio to bitmap images for display on screen
///
/// Manages a bitmap cache and paints to device contexts.
///
/// To implement a new audio renderer, see AudioRendererBitmapProvider.
class AudioRenderer {
friend struct AudioRendererBitmapCacheBitmapFactory;
/// Horizontal zoom level, milliseconds per pixel
double pixel_ms = 0.f;
/// Rendering height in pixels
int pixel_height = 0;
/// Vertical zoom level/amplitude scale
float amplitude_scale = 0.f;
/// Width of bitmaps to store in cache
const int cache_bitmap_width = 32; // Completely arbitrary value
/// Cached bitmaps for audio ranges
std::vector<AudioRendererBitmapCache> bitmaps;
/// The maximum allowed size of each bitmap cache, in bytes
size_t cache_bitmap_maxsize = 0;
/// The maximum allowed size of the renderer's cache, in bytes
size_t cache_renderer_maxsize = 0;
/// Do the caches need to be aged?
bool needs_age = false;
/// Actual renderer for bitmaps
AudioRendererBitmapProvider *renderer = nullptr;
/// Audio provider to use as source
agi::AudioProvider *provider = nullptr;
/// @brief Make sure bitmap index i is in cache
/// @param i Index of bitmap to get into cache
/// @param style Rendering style required for bitmap
/// @return The requested bitmap
///
/// Will attempt retrieving the requested bitmap from the cache, creating it
/// if the cache doesn't have it.
const wxBitmap *GetCachedBitmap(int i, AudioRenderingStyle style);
/// @brief Update the block count in the bitmap caches
///
/// Should be called when the width of the virtual bitmap has changed, i.e.
/// when the samples-per-pixel resolution or the number of audio samples
/// has changed.
void ResetBlockCount();
/// Calculate the number of cache blocks needed for a given number of samples
size_t NumBlocks(int64_t samples) const;
public:
/// @brief Constructor
///
/// Initialises audio rendering to a do-nothing state. An audio provider
/// and bitmap provider must be set before the audio renderer is functional.
AudioRenderer();
/// @brief Set horizontal zoom
/// @param pixel_ms Milliseconds per pixel to render audio at
///
/// Changing the zoom level invalidates all cached bitmaps.
void SetMillisecondsPerPixel(double pixel_ms);
/// @brief Set rendering height
/// @param pixel_height Height in pixels to render at
///
/// Changing the rendering height invalidates all cached bitmaps.
void SetHeight(int pixel_height);
/// @brief Set vertical zoom
/// @param amplitude_scale Scaling factor
///
/// Changing the scaling factor invalidates all cached bitmaps.
///
/// A scaling factor of 1.0 is no scaling, a factor of 0.5 causes the audio to be
/// rendered as if it had half its actual amplitude, a factor of 2 causes the audio
/// to be rendered as if it had double amplitude. (The exact meaning of the scaling
/// depends on the bitmap provider used.)
void SetAmplitudeScale(float amplitude_scale);
/// @brief Set the maximum allowed cache size
/// @param max_size Size in bytes that may be used for caching
///
/// The given max size is not a hard limit and does generally not include overhead
/// added by the cache management. The allowed size might be distributed among
/// several separate objects.
///
/// Changing the max cache size does not trigger cache aging.
void SetCacheMaxSize(size_t max_size);
/// @brief Change renderer
/// @param renderer New renderer to use
///
/// The consumer of audio rendering is responsible for creating, managing and destroying
/// audio bitmap providers (renderers). If a renderer was previously set with this function
/// and a new one is set, the consumer of audio rendering is still responsible for the
/// life of the old renderer.
///
/// A bitmap provider must be assigned to a newly created audio renderer before it
/// can be functional.
///
/// Changing renderer invalidates all cached bitmaps.
void SetRenderer(AudioRendererBitmapProvider *renderer);
/// @brief Change audio provider
/// @param provider New audio provider to use
///
/// The consumer of audio rendering is responsible for managing audio providers.
/// If an audio provider was previously assigned to the audio renderer and a
/// new one is assigned, the consumer of audio rendering is still responsible for
/// the life of the old audio provider.
///
/// An audio provider must be assigned to a newly created audio renderer before it
/// can be functional.
///
/// Changing audio provider invalidates all cached bitmaps.
///
/// If a renderer is set, this will also set the audio provider for the renderer.
void SetAudioProvider(agi::AudioProvider *provider);
/// @brief Render audio to a device context
/// @param dc The device context to draw to
/// @param origin Top left corner to render at, in the DC's coordinates
/// @param start First pixel from beginning of the audio stream to render
/// @param length Number of pixels of audio to render
/// @param style Style to render audio in
///
/// The first audio sample rendered is start*pixel_samples, and the number
/// of audio samples rendered is length*pixel_samples.
void Render(wxDC &dc, wxPoint origin, int start, int length, AudioRenderingStyle style);
/// @brief Invalidate all cached data
///
/// Invalidates all cached bitmaps for another reason, usually as a signal that
/// implementation-defined data in the bitmap provider have been changed.
///
/// If the consumer of audio rendering changes properties of the bitmap renderer
/// that will affect the rendered images, it should call this function to ensure
/// the cache is kept consistent.
void Invalidate();
};
/// @class AudioRendererBitmapProvider
/// @brief Base class for audio renderer implementations
///
/// Derive from this class to implement a way to render audio to images.
class AudioRendererBitmapProvider {
protected:
/// Audio provider to use for rendering
agi::AudioProvider *provider;
/// Horizontal zoom in milliseconds per pixel
double pixel_ms;
/// Vertical zoom/amplitude scale factor
float amplitude_scale;
/// @brief Called when the audio provider changes
///
/// Implementations can override this method to do something when the audio provider is changed
virtual void OnSetProvider() { }
/// @brief Called when horizontal zoom changes
///
/// Implementations can override this method to do something when the horizontal zoom is changed
virtual void OnSetMillisecondsPerPixel() { }
/// @brief Called when vertical zoom changes
///
/// Implementations can override this method to do something when the vertical zoom is changed
virtual void OnSetAmplitudeScale() { }
public:
/// @brief Constructor
AudioRendererBitmapProvider() : provider(nullptr), pixel_ms(0), amplitude_scale(0) { };
/// @brief Destructor
virtual ~AudioRendererBitmapProvider() = default;
/// @brief Rendering function
/// @param bmp Bitmap to render to
/// @param start First pixel from beginning of the audio stream to render
/// @param style Style to render audio in
///
/// Deriving classes must implement this method. The bitmap in bmp holds
/// the width and height to render.
virtual void Render(wxBitmap &bmp, int start, AudioRenderingStyle style) = 0;
/// @brief Blank audio rendering function
/// @param dc The device context to render to
/// @param rect The rectangle to fill with the image of blank audio
/// @param style Style to render audio in
///
/// Deriving classes must implement this method. The rectangle has the height
/// of the entire canvas the audio is being rendered in.
virtual void RenderBlank(wxDC &dc, const wxRect &rect, AudioRenderingStyle style) = 0;
/// @brief Change audio provider
/// @param provider Audio provider to change to
void SetProvider(agi::AudioProvider *provider);
/// @brief Change horizontal zoom
/// @param pixel_ms Milliseconds per pixel to zoom to
void SetMillisecondsPerPixel(double new_pixel_ms);
/// @brief Change vertical zoom
/// @param amplitude_scale Scaling factor to zoom to
void SetAmplitudeScale(float amplitude_scale);
/// @brief Age any caches the renderer might keep
/// @param max_size Maximum size in bytes the caches should be
///
/// Deriving classes should override this method if they implement any
/// kind of caching.
virtual void AgeCache(size_t max_size) { }
};