1/*
2 IMPORTANT: This Apple software is supplied to you by Apple Computer, Inc. ("Apple") in
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4 of this Apple software constitutes acceptance of these terms. If you do not agree with these terms,
5 please do not use, install or modify this Apple software.
6
7 In consideration of your agreement to abide by the following terms, and subject to these
8 terms, Apple grants you a personal, non-exclusive license, under Apple\xd5s copyrights in
9 this original Apple software (the "Apple Software"), to use and modify the Apple Software,
10 with or without modifications, in source and/or binary forms; provided that if you redistribute
11 the Apple Software in its entirety and without modifications, you must retain this notice and
12 the following text and disclaimers in all such redistributions of the Apple Software.
13 Neither the name, trademarks, service marks or logos of Apple Computer, Inc. may be used
14 to endorse or promote products derived from the Apple Software without specific prior
15 written permission from Apple. Except as expressly tated in this notice, no other rights or
16 licenses, express or implied, are granted by Apple herein, including but not limited
17 to any patent rights that may be infringed by your derivative works or by other works
18 in which the Apple Software may be incorporated.
19
20 The Apple Software is provided by Apple on an "AS IS" basis. APPLE MAKES NO WARRANTIES,
21 EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED WARRANTIES OF NON-INFRINGEMENT,
22 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS
23 USE AND OPERATION ALONE OR IN COMBINATION WITH YOUR PRODUCTS.
24
25 IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL
26 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27          OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) ARISING IN ANY WAY OUT OF THE USE,
28 REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED AND
29 WHETHER UNDER THEORY OF CONTRACT, TORT (INCLUDING NEGLIGENCE), STRICT LIABILITY OR
30 OTHERWISE, EVEN IF APPLE HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#import <CoreFoundation/CoreFoundation.h>
34#import <ApplicationServices/ApplicationServices.h>
35#import <OpenGL/OpenGL.h>
36#import <OpenGL/gl.h>
37
38#include "wx/mac/common/glgrab.h"
39
40
41/*
42 * perform an in-place swap from Quadrant 1 to Quadrant III format
43 * (upside-down PostScript/GL to right side up QD/CG raster format)
44 * We do this in-place, which requires more copying, but will touch
45 * only half the pages.  (Display grabs are BIG!)
46 *
47 * Pixel reformatting may optionally be done here if needed.
48 */
49static void swizzleBitmap(void * data, int rowBytes, int height)
50{
51    int top, bottom;
52    void * buffer;
53    void * topP;
54    void * bottomP;
55    void * base;
56
57
58    top = 0;
59    bottom = height - 1;
60    base = data;
61    buffer = malloc(rowBytes);
62
63
64    while ( top < bottom )
65    {
66        topP = (void *)((top * rowBytes) + (intptr_t)base);
67        bottomP = (void *)((bottom * rowBytes) + (intptr_t)base);
68
69
70        /*
71         * Save and swap scanlines.
72         *
73         * This code does a simple in-place exchange with a temp buffer.
74         * If you need to reformat the pixels, replace the first two bcopy()
75         * calls with your own custom pixel reformatter.
76         */
77        bcopy( topP, buffer, rowBytes );
78        bcopy( bottomP, topP, rowBytes );
79        bcopy( buffer, bottomP, rowBytes );
80
81        ++top;
82        --bottom;
83    }
84    free( buffer );
85}
86
87
88/*
89 * Given a display ID and a rectangle on that display, generate a CGImageRef
90 * containing the display contents.
91 *
92 * srcRect is display-origin relative.
93 *
94 * This function uses a full screen OpenGL read-only context.
95 * By using OpenGL, we can read the screen using a DMA transfer
96 * when it's in millions of colors mode, and we can correctly read
97 * a microtiled full screen OpenGL context, such as a game or full
98 * screen video display.
99 *
100 * Returns a CGImageRef. When you are done with the CGImageRef, release it
101 * using CFRelease().
102 * Returns NULL on an error.
103 */
104
105extern CGColorSpaceRef wxMacGetGenericRGBColorSpace();
106
107CGImageRef grabViaOpenGL(CGDirectDisplayID display, CGRect srcRect)
108{
109    CGContextRef bitmap;
110    CGImageRef image;
111    void * data;
112    long bytewidth;
113    GLint width, height;
114    long bytes;
115
116    CGLContextObj    glContextObj;
117    CGLPixelFormatObj pixelFormatObj ;
118    long numPixelFormats ;
119    CGLPixelFormatAttribute attribs[] =
120    {
121        kCGLPFAFullScreen,
122        kCGLPFADisplayMask,
123        0,    /* Display mask bit goes here */
124        0
125    } ;
126
127
128    if ( display == kCGNullDirectDisplay )
129        display = CGMainDisplayID();
130    attribs[2] = CGDisplayIDToOpenGLDisplayMask(display);
131
132
133    /* Build a full-screen GL context */
134    CGLChoosePixelFormat( attribs, &pixelFormatObj, &numPixelFormats );
135    if ( pixelFormatObj == NULL )    // No full screen context support
136        return NULL;
137    CGLCreateContext( pixelFormatObj, NULL, &glContextObj ) ;
138    CGLDestroyPixelFormat( pixelFormatObj ) ;
139    if ( glContextObj == NULL )
140        return NULL;
141
142
143    CGLSetCurrentContext( glContextObj ) ;
144    CGLSetFullScreen( glContextObj ) ;
145
146
147    glReadBuffer(GL_FRONT);
148
149
150    width = srcRect.size.width;
151    height = srcRect.size.height;
152
153
154    bytewidth = width * 4; // Assume 4 bytes/pixel for now
155    bytewidth = (bytewidth + 3) & ~3; // Align to 4 bytes
156    bytes = bytewidth * height; // width * height
157
158    /* Build bitmap context */
159    data = malloc(height * bytewidth);
160    if ( data == NULL )
161    {
162        CGLSetCurrentContext( NULL );
163        CGLClearDrawable( glContextObj ); // disassociate from full screen
164        CGLDestroyContext( glContextObj ); // and destroy the context
165        return NULL;
166    }
167    bitmap = CGBitmapContextCreate(data, width, height, 8, bytewidth,
168                                   wxMacGetGenericRGBColorSpace(), kCGImageAlphaNoneSkipFirst /* XRGB */);
169
170
171    /* Read framebuffer into our bitmap */
172    glFinish(); /* Finish all OpenGL commands */
173    glPixelStorei(GL_PACK_ALIGNMENT, 4); /* Force 4-byte alignment */
174    glPixelStorei(GL_PACK_ROW_LENGTH, 0);
175    glPixelStorei(GL_PACK_SKIP_ROWS, 0);
176    glPixelStorei(GL_PACK_SKIP_PIXELS, 0);
177
178    /*
179     * Fetch the data in XRGB format, matching the bitmap context.
180     */
181    glReadPixels((GLint)srcRect.origin.x, (GLint)srcRect.origin.y, width, height,
182                 GL_BGRA,
183#ifdef __BIG_ENDIAN__
184                 GL_UNSIGNED_INT_8_8_8_8_REV, // for PPC
185#else
186                 GL_UNSIGNED_INT_8_8_8_8, // for Intel! http://lists.apple.com/archives/quartz-dev/2006/May/msg00100.html
187#endif
188                 data);
189    /*
190     * glReadPixels generates a quadrant I raster, with origin in the lower left
191     * This isn't a problem for signal processing routines such as compressors,
192     * as they can simply use a negative 'advance' to move between scanlines.
193     * CGImageRef and CGBitmapContext assume a quadrant III raster, though, so we need to
194     * invert it. Pixel reformatting can also be done here.
195     */
196    swizzleBitmap(data, bytewidth, height);
197
198
199    /* Make an image out of our bitmap; does a cheap vm_copy of the bitmap */
200    image = CGBitmapContextCreateImage(bitmap);
201
202    /* Get rid of bitmap */
203    CFRelease(bitmap);
204    free(data);
205
206
207    /* Get rid of GL context */
208    CGLSetCurrentContext( NULL );
209    CGLClearDrawable( glContextObj ); // disassociate from full screen
210    CGLDestroyContext( glContextObj ); // and destroy the context
211
212    /* Returned image has a reference count of 1 */
213    return image;
214}
215
216