KiCad PCB EDA Suite
cairo_compositor.cpp
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1 /*
2  * This program source code file is part of KiCad, a free EDA CAD application.
3  *
4  * Copyright (C) 2013 CERN
5  * @author Maciej Suminski <maciej.suminski@cern.ch>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
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23  */
24 
32 #include <wx/log.h>
33 
34 using namespace KIGFX;
35 
36 CAIRO_COMPOSITOR::CAIRO_COMPOSITOR( cairo_t** aMainContext ) :
37  m_current( 0 ), m_currentContext( aMainContext ), m_mainContext( *aMainContext )
38 {
39  // Do not have uninitialized members:
40  cairo_matrix_init_identity( &m_matrix );
41  m_stride = 0;
42  m_bufferSize = 0;
43 }
44 
45 
47 {
48  clean();
49 }
50 
51 
53 {
54  // Nothing has to be done
55 }
56 
57 
58 void CAIRO_COMPOSITOR::Resize( unsigned int aWidth, unsigned int aHeight )
59 {
60  clean();
61 
62  m_width = aWidth;
63  m_height = aHeight;
64 
65  m_stride = cairo_format_stride_for_width( CAIRO_FORMAT_ARGB32, m_width );
67 }
68 
69 
71 {
72  // Pixel storage
73  BitmapPtr bitmap( new unsigned int[m_bufferSize] );
74 
75  memset( bitmap.get(), 0x00, m_bufferSize * sizeof(int) );
76 
77  // Create the Cairo surface
78  cairo_surface_t* surface = cairo_image_surface_create_for_data(
79  (unsigned char*) bitmap.get(),
80  CAIRO_FORMAT_ARGB32, m_width,
81  m_height, m_stride );
82  cairo_t* context = cairo_create( surface );
83 #ifdef __WXDEBUG__
84  cairo_status_t status = cairo_status( context );
85  wxASSERT_MSG( status == CAIRO_STATUS_SUCCESS, wxT( "Cairo context creation error" ) );
86 #endif /* __WXDEBUG__ */
87 
88  // Set default settings for the buffer
89  cairo_set_antialias( context, CAIRO_ANTIALIAS_NONE );
90  cairo_set_line_join( context, CAIRO_LINE_JOIN_ROUND );
91  cairo_set_line_cap( context, CAIRO_LINE_CAP_ROUND );
92 
93  // Use the same transformation matrix as the main context
94  cairo_get_matrix( m_mainContext, &m_matrix );
95  cairo_set_matrix( context, &m_matrix );
96 
97  // Store the new buffer
98  CAIRO_BUFFER buffer = { context, surface, bitmap };
99  m_buffers.push_back( buffer );
100 
101  return usedBuffers();
102 }
103 
104 
105 void CAIRO_COMPOSITOR::SetBuffer( unsigned int aBufferHandle )
106 {
107  wxASSERT_MSG( aBufferHandle <= usedBuffers(), wxT( "Tried to use a not existing buffer" ) );
108 
109  // Get currently used transformation matrix, so it can be applied to the new buffer
110  cairo_get_matrix( *m_currentContext, &m_matrix );
111 
112  m_current = aBufferHandle - 1;
114 
115  // Apply the current transformation matrix
116  cairo_set_matrix( *m_currentContext, &m_matrix );
117 }
118 
120 {
121 }
122 
124 {
125  // Clear the pixel storage
126  memset( m_buffers[m_current].bitmap.get(), 0x00, m_bufferSize * sizeof(int) );
127 }
128 
129 
130 void CAIRO_COMPOSITOR::DrawBuffer( unsigned int aBufferHandle )
131 {
132  wxASSERT_MSG( aBufferHandle <= usedBuffers(), wxT( "Tried to use a not existing buffer" ) );
133 
134  // Reset the transformation matrix, so it is possible to composite images using
135  // screen coordinates instead of world coordinates
136  cairo_get_matrix( m_mainContext, &m_matrix );
137  cairo_identity_matrix( m_mainContext );
138 
139  // Draw the selected buffer contents
140  cairo_set_source_surface( m_mainContext, m_buffers[aBufferHandle - 1].surface, 0.0, 0.0 );
141  cairo_paint( m_mainContext );
142 
143  // Restore the transformation matrix
144  cairo_set_matrix( m_mainContext, &m_matrix );
145 }
146 
148 {
149 }
150 
152 {
153  CAIRO_BUFFERS::const_iterator it;
154 
155  for( it = m_buffers.begin(); it != m_buffers.end(); ++it )
156  {
157  cairo_destroy( it->context );
158  cairo_surface_destroy( it->surface );
159  }
160 
161  m_buffers.clear();
162 }
void clean()
Function clean() performs freeing of resources.
unsigned int m_stride
Stride to use given the desired format and width.
Class CAIRO_GAL is the cairo implementation of the graphics abstraction layer.
Definition: class_module.h:58
unsigned int m_width
Width of the buffer (in pixels)
Definition: compositor.h:119
virtual void Begin() override
Function Begin() Call this at the beginning of each frame.
virtual void Present() override
Function Present() Call this to present the output buffer to the screen.
unsigned int usedBuffers()
Returns number of currently used buffers.
virtual void ClearBuffer(const COLOR4D &aColor) override
Function ClearBuffer() clears the selected buffer (set by the SetBuffer() function).
virtual void SetBuffer(unsigned int aBufferHandle) override
Function SetBuffer() sets the selected buffer as the rendering target.
unsigned int m_current
Currently used buffer handle.
CAIRO_BUFFERS m_buffers
Stores information about initialized buffers.
Class that handles multitarget rendering (ie.
cairo_t ** m_currentContext
Pointer to the current context, so it can be changed.
virtual void DrawBuffer(unsigned int aBufferHandle) override
Function DrawBuffer() draws the selected buffer to the output buffer.
unsigned int m_bufferSize
Amount of memory needed to store a buffer.
virtual void Initialize() override
Function Reset() performs primary initialiation, necessary to use the object.
boost::shared_array< unsigned int > BitmapPtr
CAIRO_COMPOSITOR(cairo_t **aMainContext)
virtual void Resize(unsigned int aWidth, unsigned int aHeight) override
Function Resize() clears the state of COMPOSITOR, so it has to be reinitialized again with the new di...
cairo_matrix_t m_matrix
Transformation matrix.
cairo_t * m_mainContext
Rendering target used for compositing (the main display)
unsigned int m_height
Height of the buffer (in pixels)
Definition: compositor.h:120
virtual unsigned int CreateBuffer() override
Function CreateBuffer() prepares a new buffer that may be used as a rendering target.
Class COLOR4D is the color representation with 4 components: red, green, blue, alpha.
Definition: color4d.h:39