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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12  * This program is distributed in the hope that it will be useful,
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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  assert( aWidth > 0 );
63  assert( aHeight > 0 );
64 
65  m_width = aWidth;
66  m_height = aHeight;
67 
68  m_stride = cairo_format_stride_for_width( CAIRO_FORMAT_ARGB32, m_width );
70 }
71 
72 
74 {
75  // Pixel storage
76  BitmapPtr bitmap( new unsigned int[m_bufferSize] );
77 
78  memset( bitmap.get(), 0x00, m_bufferSize * sizeof(int) );
79 
80  // Create the Cairo surface
81  cairo_surface_t* surface = cairo_image_surface_create_for_data(
82  (unsigned char*) bitmap.get(),
83  CAIRO_FORMAT_ARGB32, m_width,
84  m_height, m_stride );
85  cairo_t* context = cairo_create( surface );
86 #ifdef __WXDEBUG__
87  cairo_status_t status = cairo_status( context );
88  wxASSERT_MSG( status == CAIRO_STATUS_SUCCESS, wxT( "Cairo context creation error" ) );
89 #endif /* __WXDEBUG__ */
90 
91  // Set default settings for the buffer
92  cairo_set_antialias( context, CAIRO_ANTIALIAS_NONE );
93  cairo_set_line_join( context, CAIRO_LINE_JOIN_ROUND );
94  cairo_set_line_cap( context, CAIRO_LINE_CAP_ROUND );
95 
96  // Use the same transformation matrix as the main context
97  cairo_get_matrix( m_mainContext, &m_matrix );
98  cairo_set_matrix( context, &m_matrix );
99 
100  // Store the new buffer
101  CAIRO_BUFFER buffer = { context, surface, bitmap };
102  m_buffers.push_back( buffer );
103 
104  return usedBuffers();
105 }
106 
107 
108 void CAIRO_COMPOSITOR::SetBuffer( unsigned int aBufferHandle )
109 {
110  wxASSERT_MSG( aBufferHandle <= usedBuffers(), wxT( "Tried to use a not existing buffer" ) );
111 
112  // Get currently used transformation matrix, so it can be applied to the new buffer
113  cairo_get_matrix( *m_currentContext, &m_matrix );
114 
115  m_current = aBufferHandle - 1;
117 
118  // Apply the current transformation matrix
119  cairo_set_matrix( *m_currentContext, &m_matrix );
120 }
121 
123 {
124 }
125 
127 {
128  // Clear the pixel storage
129  memset( m_buffers[m_current].bitmap.get(), 0x00, m_bufferSize * sizeof(int) );
130 }
131 
132 
133 void CAIRO_COMPOSITOR::DrawBuffer( unsigned int aBufferHandle )
134 {
135  wxASSERT_MSG( aBufferHandle <= usedBuffers(), wxT( "Tried to use a not existing buffer" ) );
136 
137  // Reset the transformation matrix, so it is possible to composite images using
138  // screen coordinates instead of world coordinates
139  cairo_get_matrix( m_mainContext, &m_matrix );
140  cairo_identity_matrix( m_mainContext );
141 
142  // Draw the selected buffer contents
143  cairo_set_source_surface( m_mainContext, m_buffers[aBufferHandle - 1].surface, 0.0, 0.0 );
144  cairo_paint( m_mainContext );
145 
146  // Restore the transformation matrix
147  cairo_set_matrix( m_mainContext, &m_matrix );
148 }
149 
151 {
152 }
153 
155 {
156  CAIRO_BUFFERS::const_iterator it;
157 
158  for( it = m_buffers.begin(); it != m_buffers.end(); ++it )
159  {
160  cairo_destroy( it->context );
161  cairo_surface_destroy( it->surface );
162  }
163 
164  m_buffers.clear();
165 }
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