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Viewing changes to src/shell-screen-grabber.c

Tags: upstream-3.3.90
Import upstream version 3.3.90

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src/shell-screen-grabber.c
 
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/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
 
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#include <string.h>
 
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#include <clutter/clutter.h>
 
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#include <cogl/cogl.h>
 
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#include <GL/gl.h>
 
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#include <GL/glx.h>
 
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#include <GL/glext.h>
 
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#include "shell-screen-grabber.h"
 
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PFNGLBINDBUFFERARBPROC pf_glBindBufferARB;
 
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PFNGLBUFFERDATAARBPROC pf_glBufferDataARB;
 
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PFNGLDELETEBUFFERSARBPROC pf_glDeleteBuffersARB;
 
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PFNGLGENBUFFERSARBPROC pf_glGenBuffersARB;
 
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PFNGLMAPBUFFERARBPROC pf_glMapBufferARB;
 
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PFNGLUNMAPBUFFERARBPROC pf_glUnmapBufferARB;
 
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struct _ShellScreenGrabberClass
 
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{
 
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  GObjectClass parent_class;
 
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};
 
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struct _ShellScreenGrabber
 
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{
 
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  GObject parent_instance;
 
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  int have_pixel_buffers;
 
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  int have_pack_invert;
 
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  int width, height;
 
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  GLuint pixel_buffer;
 
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};
 
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G_DEFINE_TYPE(ShellScreenGrabber, shell_screen_grabber, G_TYPE_OBJECT);
 
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static void
 
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shell_screen_grabber_finalize (GObject *gobject)
 
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{
 
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  ShellScreenGrabber *grabber = SHELL_SCREEN_GRABBER (gobject);
 
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  if (grabber->pixel_buffer != 0)
 
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    pf_glDeleteBuffersARB (1, &grabber->pixel_buffer);
 
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}
 
45
 
 
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static void
 
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shell_screen_grabber_class_init (ShellScreenGrabberClass *grabber_class)
 
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{
 
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  GObjectClass *gobject_class = G_OBJECT_CLASS (grabber_class);
 
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  gobject_class->finalize = shell_screen_grabber_finalize;
 
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}
 
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static void
 
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shell_screen_grabber_init (ShellScreenGrabber *grabber)
 
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{
 
57
  grabber->have_pixel_buffers = -1;
 
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  grabber->width = -1;
 
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  grabber->height= -1;
 
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  grabber->pixel_buffer = 0;
 
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}
 
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ShellScreenGrabber *
 
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shell_screen_grabber_new  (void)
 
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{
 
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  return g_object_new (SHELL_TYPE_SCREEN_GRABBER, NULL);
 
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}
 
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/**
 
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 * shell_screen_grabber_grab:
 
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 * x: X coordinate of the rectangle to grab
 
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 * y: Y coordinate of the rectangle to grab
 
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 * width: width of the rectangle to grab
 
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 * height: heigth of the rectangle to grab
 
75
 *
 
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 * Grabs pixel data from a portion of the screen.
 
77
 *
 
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 * Return value: buffer holding the grabbed data. The data is stored as 32-bit
 
79
 *  words with native-endian xRGB pixels (i.e., the same as CAIRO_FORMAT_RGB24)
 
80
 *  with no padding on the rows. So, the size of the buffer is width * height * 4
 
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 *  bytes. Free with g_free().
 
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 **/
 
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guchar *
 
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shell_screen_grabber_grab (ShellScreenGrabber *grabber,
 
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                           int                 x,
 
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                           int                 y,
 
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                           int                 width,
 
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                           int                 height)
 
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{
 
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  guchar *data;
 
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  gsize row_bytes;
 
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  gsize data_size;
 
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  row_bytes = width * 4;
 
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  data_size = row_bytes * height;
 
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  data = g_malloc (data_size);
 
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  if (grabber->have_pixel_buffers == -1)
 
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    {
 
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      const GLubyte* extensions = glGetString (GL_EXTENSIONS);
 
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      grabber->have_pixel_buffers = strstr ((const char *)extensions, "GL_EXT_pixel_buffer_object") != NULL;
 
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      grabber->have_pack_invert = strstr ((const char *)extensions, "GL_MESA_pack_invert") != NULL;
 
103
    }
 
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  if (grabber->have_pixel_buffers)
 
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    {
 
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      GLubyte *mapped_data;
 
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      GLint old_swap_bytes, old_lsb_first, old_row_length, old_skip_pixels, old_skip_rows, old_alignment;
 
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      GLint old_pack_invert = GL_FALSE;
 
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      guchar *src_row, *dest_row;
 
111
      int i;
 
112
 
 
113
      cogl_flush ();
 
114
 
 
115
      if (pf_glBindBufferARB == NULL)
 
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        {
 
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          pf_glBindBufferARB = (PFNGLBINDBUFFERARBPROC) cogl_get_proc_address ("glBindBufferARB");
 
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          pf_glBufferDataARB = (PFNGLBUFFERDATAARBPROC) cogl_get_proc_address ("glBufferDataARB");
 
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          pf_glDeleteBuffersARB = (PFNGLDELETEBUFFERSARBPROC) cogl_get_proc_address ("glDeleteBuffersARB");
 
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          pf_glGenBuffersARB = (PFNGLGENBUFFERSARBPROC) cogl_get_proc_address ("glGenBuffersARB");
 
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          pf_glMapBufferARB = (PFNGLMAPBUFFERARBPROC) cogl_get_proc_address ("glMapBufferARB");
 
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          pf_glUnmapBufferARB = (PFNGLUNMAPBUFFERARBPROC) cogl_get_proc_address ("glUnmapBufferARB");
 
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        }
 
124
 
 
125
      glGetIntegerv (GL_PACK_SWAP_BYTES, &old_swap_bytes);
 
126
      glGetIntegerv (GL_PACK_LSB_FIRST, &old_lsb_first);
 
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      glGetIntegerv (GL_PACK_ROW_LENGTH, &old_row_length);
 
128
      glGetIntegerv (GL_PACK_SKIP_PIXELS, &old_skip_pixels);
 
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      glGetIntegerv (GL_PACK_SKIP_ROWS, &old_skip_rows);
 
130
      glGetIntegerv (GL_PACK_ALIGNMENT, &old_alignment);
 
131
 
 
132
      glPixelStorei (GL_PACK_SWAP_BYTES, GL_FALSE);
 
133
      glPixelStorei (GL_PACK_LSB_FIRST, GL_FALSE);
 
134
      glPixelStorei (GL_PACK_ROW_LENGTH, 0);
 
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      glPixelStorei (GL_PACK_SKIP_PIXELS, 0);
 
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      glPixelStorei (GL_PACK_SKIP_ROWS, 0);
 
137
      glPixelStorei (GL_PACK_ALIGNMENT, 1);
 
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139
      if (grabber->have_pack_invert)
 
140
        {
 
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          glGetIntegerv (GL_PACK_INVERT_MESA, &old_pack_invert);
 
142
          glPixelStorei (GL_PACK_INVERT_MESA, GL_FALSE);
 
143
        }
 
144
 
 
145
      if (grabber->pixel_buffer != 0 &&
 
146
          (grabber->width != width ||
 
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           grabber->height != height))
 
148
        {
 
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          pf_glDeleteBuffersARB (1, &grabber->pixel_buffer);
 
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          grabber->pixel_buffer = 0;
 
151
        }
 
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153
      if (grabber->pixel_buffer == 0)
 
154
        {
 
155
          pf_glGenBuffersARB (1, &grabber->pixel_buffer);
 
156
 
 
157
          pf_glBindBufferARB (GL_PIXEL_PACK_BUFFER_ARB, grabber->pixel_buffer);
 
158
          pf_glBufferDataARB (GL_PIXEL_PACK_BUFFER_ARB, data_size, 0, GL_STREAM_READ_ARB);
 
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160
          grabber->width = width;
 
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          grabber->height = height;
 
162
        }
 
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      else
 
164
        {
 
165
          pf_glBindBufferARB (GL_PIXEL_PACK_BUFFER_ARB, grabber->pixel_buffer);
 
166
        }
 
167
 
 
168
      glReadPixels (x, y, width, height, GL_BGRA, GL_UNSIGNED_BYTE, 0);
 
169
 
 
170
      mapped_data = pf_glMapBufferARB (GL_PIXEL_PACK_BUFFER_ARB, GL_READ_ONLY_ARB);
 
171
 
 
172
      src_row = mapped_data + (height - 1) * row_bytes;
 
173
      dest_row = data;
 
174
 
 
175
      for (i = 0; i < height; i++)
 
176
        {
 
177
          memcpy (dest_row, src_row, row_bytes);
 
178
          src_row -= row_bytes;
 
179
          dest_row += row_bytes;
 
180
        }
 
181
 
 
182
      pf_glUnmapBufferARB (GL_PIXEL_PACK_BUFFER_ARB);
 
183
      pf_glBindBufferARB (GL_PIXEL_PACK_BUFFER_ARB, 0);
 
184
 
 
185
      glPixelStorei (GL_PACK_SWAP_BYTES, old_swap_bytes);
 
186
      glPixelStorei (GL_PACK_LSB_FIRST, old_lsb_first);
 
187
      glPixelStorei (GL_PACK_ROW_LENGTH, old_row_length);
 
188
      glPixelStorei (GL_PACK_SKIP_PIXELS, old_skip_pixels);
 
189
      glPixelStorei (GL_PACK_SKIP_ROWS, old_skip_rows);
 
190
      glPixelStorei (GL_PACK_ALIGNMENT, old_alignment);
 
191
 
 
192
      if (grabber->have_pack_invert)
 
193
        glPixelStorei (GL_PACK_INVERT_MESA, old_pack_invert);
 
194
    }
 
195
  else
 
196
    {
 
197
      cogl_read_pixels (x, y,
 
198
                        width, height,
 
199
                        COGL_READ_PIXELS_COLOR_BUFFER,
 
200
                        CLUTTER_CAIRO_FORMAT_ARGB32,
 
201
                        data);
 
202
    }
 
203
 
 
204
  return data;
 
205
}