Exemplo n.º 1
0
static void
set_clip_plane (GLint plane_num,
		const float *vertex_a,
		const float *vertex_b)
{
#if defined (HAVE_COGL_GLES2) || defined (HAVE_COGL_GLES)
  GLfloat plane[4];
#else
  GLdouble plane[4];
#endif
  GLfloat angle;
  CoglHandle framebuffer = _cogl_get_framebuffer ();
  CoglMatrixStack *modelview_stack =
    _cogl_framebuffer_get_modelview_stack (framebuffer);
  CoglMatrixStack *projection_stack =
    _cogl_framebuffer_get_projection_stack (framebuffer);
  CoglMatrix inverse_projection;

  _COGL_GET_CONTEXT (ctx, NO_RETVAL);

  _cogl_matrix_stack_get_inverse (projection_stack, &inverse_projection);

  /* Calculate the angle between the axes and the line crossing the
     two points */
  angle = atan2f (vertex_b[1] - vertex_a[1],
                  vertex_b[0] - vertex_a[0]) * (180.0/G_PI);

  _cogl_matrix_stack_push (modelview_stack);

  /* Load the inverse of the projection matrix so we can specify the plane
   * in screen coordinates */
  _cogl_matrix_stack_set (modelview_stack, &inverse_projection);

  /* Rotate about point a */
  _cogl_matrix_stack_translate (modelview_stack,
                                vertex_a[0], vertex_a[1], vertex_a[2]);
  /* Rotate the plane by the calculated angle so that it will connect
     the two points */
  _cogl_matrix_stack_rotate (modelview_stack, angle, 0.0f, 0.0f, 1.0f);
  _cogl_matrix_stack_translate (modelview_stack,
                                -vertex_a[0], -vertex_a[1], -vertex_a[2]);

  _cogl_matrix_stack_flush_to_gl (modelview_stack, COGL_MATRIX_MODELVIEW);

  plane[0] = 0;
  plane[1] = -1.0;
  plane[2] = 0;
  plane[3] = vertex_a[1];
#if defined (HAVE_COGL_GLES2) || defined (HAVE_COGL_GLES)
  GE( glClipPlanef (plane_num, plane) );
#else
  GE( glClipPlane (plane_num, plane) );
#endif

  _cogl_matrix_stack_pop (modelview_stack);
}
Exemplo n.º 2
0
void
_cogl_flush_clip_state (CoglClipStackState *clip_state)
{
  CoglClipStack *stack;
  int has_clip_planes;
  gboolean using_clip_planes = FALSE;
  gboolean using_stencil_buffer = FALSE;
  GList *node;
  int scissor_x0 = 0;
  int scissor_y0 = 0;
  int scissor_x1 = G_MAXINT;
  int scissor_y1 = G_MAXINT;
  CoglMatrixStack *modelview_stack =
    _cogl_framebuffer_get_modelview_stack (_cogl_get_framebuffer ());

  if (!clip_state->stack_dirty)
    return;

  /* The current primitive journal does not support tracking changes to the
   * clip stack...  */
  _cogl_journal_flush ();

  /* XXX: the handling of clipping is quite complex. It may involve use of
   * the Cogl Journal or other Cogl APIs which may end up recursively
   * wanting to ensure the clip state is flushed. We need to ensure we
   * don't recurse infinitely...
   */
  clip_state->stack_dirty = FALSE;

  has_clip_planes = cogl_features_available (COGL_FEATURE_FOUR_CLIP_PLANES);

  stack = clip_state->stacks->data;

  clip_state->stencil_used = FALSE;

  disable_clip_planes ();
  disable_stencil_buffer ();
  GE (glDisable (GL_SCISSOR_TEST));

  /* If the stack is empty then there's nothing else to do */
  if (stack->stack_top == NULL)
    return;

  /* Find the bottom of the stack */
  for (node = stack->stack_top; node->next; node = node->next);

  /* Re-add every entry from the bottom of the stack up */
  for (; node; node = node->prev)
    {
      gpointer entry = node->data;
      CoglClipStackEntryType type = *(CoglClipStackEntryType *) entry;

      if (type == COGL_CLIP_STACK_PATH)
        {
          CoglClipStackEntryPath *path = (CoglClipStackEntryPath *) entry;

          _cogl_matrix_stack_push (modelview_stack);
          _cogl_matrix_stack_set (modelview_stack, &path->matrix);

          _cogl_add_path_to_stencil_buffer (path->path_nodes_min,
                                            path->path_nodes_max,
                                            path->path_size,
                                            path->path,
                                            using_stencil_buffer,
                                            TRUE);

          _cogl_matrix_stack_pop (modelview_stack);

          using_stencil_buffer = TRUE;

          /* We can't use clip planes any more */
          has_clip_planes = FALSE;
        }
      else if (type == COGL_CLIP_STACK_RECT)
        {
          CoglClipStackEntryRect *rect = (CoglClipStackEntryRect *) entry;

          _cogl_matrix_stack_push (modelview_stack);
          _cogl_matrix_stack_set (modelview_stack, &rect->matrix);

          /* If this is the first entry and we support clip planes then use
             that instead */
          if (has_clip_planes)
            {
              set_clip_planes (rect->x0,
                               rect->y0,
                               rect->x1,
                               rect->y1);
              using_clip_planes = TRUE;
              /* We can't use clip planes a second time */
              has_clip_planes = FALSE;
            }
          else
            {
              add_stencil_clip_rectangle (rect->x0,
                                          rect->y0,
                                          rect->x1,
                                          rect->y1,
                                          !using_stencil_buffer);
              using_stencil_buffer = TRUE;
            }

          _cogl_matrix_stack_pop (modelview_stack);
        }
      else
        {
          /* Get the intersection of all window space rectangles in the clip
           * stack */
          CoglClipStackEntryWindowRect *window_rect = entry;
          scissor_x0 = MAX (scissor_x0, window_rect->x0);
          scissor_y0 = MAX (scissor_y0, window_rect->y0);
          scissor_x1 = MIN (scissor_x1, window_rect->x1);
          scissor_y1 = MIN (scissor_y1, window_rect->y1);
        }
    }

  /* Enabling clip planes is delayed to now so that they won't affect
     setting up the stencil buffer */
  if (using_clip_planes)
    enable_clip_planes ();

  if (scissor_x0 >= scissor_x1 || scissor_y0 >= scissor_y1)
    scissor_x0 = scissor_y0 = scissor_x1 = scissor_y1 = 0;

  if (!(scissor_x0 == 0 && scissor_y0 == 0 &&
        scissor_x1 == G_MAXINT && scissor_y1 == G_MAXINT))
    {
      GE (glEnable (GL_SCISSOR_TEST));
      GE (glScissor (scissor_x0, scissor_y0,
                     scissor_x1 - scissor_x0,
                     scissor_y1 - scissor_y0));
    }

  clip_state->stencil_used = using_stencil_buffer;
}
Exemplo n.º 3
0
void
add_stencil_clip_rectangle (float x_1,
                            float y_1,
                            float x_2,
                            float y_2,
                            gboolean first)
{
  CoglHandle current_source;
  CoglHandle framebuffer = _cogl_get_framebuffer ();

  _COGL_GET_CONTEXT (ctx, NO_RETVAL);

  /* We don't log changes to the stencil buffer so need to flush any
   * batched geometry before we start... */
  _cogl_journal_flush ();

  _cogl_framebuffer_flush_state (framebuffer, 0);

  /* temporarily swap in our special stenciling material */
  current_source = cogl_handle_ref (ctx->source_material);
  cogl_set_source (ctx->stencil_material);

  if (first)
    {
      GE( glEnable (GL_STENCIL_TEST) );

      /* Initially disallow everything */
      GE( glClearStencil (0) );
      GE( glClear (GL_STENCIL_BUFFER_BIT) );

      /* Punch out a hole to allow the rectangle */
      GE( glStencilFunc (GL_NEVER, 0x1, 0x1) );
      GE( glStencilOp (GL_REPLACE, GL_REPLACE, GL_REPLACE) );

      cogl_rectangle (x_1, y_1, x_2, y_2);
    }
  else
    {
      CoglMatrixStack *modelview_stack =
        _cogl_framebuffer_get_modelview_stack (framebuffer);
      CoglMatrixStack *projection_stack =
        _cogl_framebuffer_get_projection_stack (framebuffer);

      /* Add one to every pixel of the stencil buffer in the
	 rectangle */
      GE( glStencilFunc (GL_NEVER, 0x1, 0x3) );
      GE( glStencilOp (GL_INCR, GL_INCR, GL_INCR) );
      cogl_rectangle (x_1, y_1, x_2, y_2);

      /* make sure our rectangle hits the stencil buffer before we
       * change the stencil operation */
      _cogl_journal_flush ();

      /* Subtract one from all pixels in the stencil buffer so that
	 only pixels where both the original stencil buffer and the
	 rectangle are set will be valid */
      GE( glStencilOp (GL_DECR, GL_DECR, GL_DECR) );

      _cogl_matrix_stack_push (projection_stack);
      _cogl_matrix_stack_load_identity (projection_stack);

      _cogl_matrix_stack_push (modelview_stack);
      _cogl_matrix_stack_load_identity (modelview_stack);

      cogl_rectangle (-1.0, -1.0, 1.0, 1.0);

      _cogl_matrix_stack_pop (modelview_stack);
      _cogl_matrix_stack_pop (projection_stack);
    }

  /* make sure our rectangles hit the stencil buffer before we restore
   * the stencil function / operation */
  _cogl_journal_flush ();

  /* Restore the stencil mode */
  GE( glStencilFunc (GL_EQUAL, 0x1, 0x1) );
  GE( glStencilOp (GL_KEEP, GL_KEEP, GL_KEEP) );

  /* restore the original source material */
  cogl_set_source (current_source);
  cogl_handle_unref (current_source);
}
Exemplo n.º 4
0
static void
set_clip_plane (CoglFramebuffer *framebuffer,
                GLint plane_num,
		const float *vertex_a,
		const float *vertex_b)
{
  GLfloat planef[4];
  double planed[4];
  GLfloat angle;
  CoglMatrixStack *modelview_stack =
    _cogl_framebuffer_get_modelview_stack (framebuffer);
  CoglMatrixStack *projection_stack =
    _cogl_framebuffer_get_projection_stack (framebuffer);
  CoglMatrix inverse_projection;

  _COGL_GET_CONTEXT (ctx, NO_RETVAL);

  _cogl_matrix_stack_get_inverse (projection_stack, &inverse_projection);

  /* Calculate the angle between the axes and the line crossing the
     two points */
  angle = atan2f (vertex_b[1] - vertex_a[1],
                  vertex_b[0] - vertex_a[0]) * (180.0/G_PI);

  _cogl_matrix_stack_push (modelview_stack);

  /* Load the inverse of the projection matrix so we can specify the plane
   * in screen coordinates */
  _cogl_matrix_stack_set (modelview_stack, &inverse_projection);

  /* Rotate about point a */
  _cogl_matrix_stack_translate (modelview_stack,
                                vertex_a[0], vertex_a[1], vertex_a[2]);
  /* Rotate the plane by the calculated angle so that it will connect
     the two points */
  _cogl_matrix_stack_rotate (modelview_stack, angle, 0.0f, 0.0f, 1.0f);
  _cogl_matrix_stack_translate (modelview_stack,
                                -vertex_a[0], -vertex_a[1], -vertex_a[2]);

  /* Clip planes can only be used when a fixed function backend is in
     use so we know we can directly push this matrix to the builtin
     state */
  _cogl_matrix_entry_flush_to_gl_builtins (ctx,
                                           modelview_stack->last_entry,
                                           COGL_MATRIX_MODELVIEW,
                                           framebuffer,
                                           FALSE /* don't disable flip */);

  planef[0] = 0;
  planef[1] = -1.0;
  planef[2] = 0;
  planef[3] = vertex_a[1];

  switch (ctx->driver)
    {
    default:
      g_assert_not_reached ();
      break;

    case COGL_DRIVER_GLES1:
      GE( ctx, glClipPlanef (plane_num, planef) );
      break;

    case COGL_DRIVER_GL:
      planed[0] = planef[0];
      planed[1] = planef[1];
      planed[2] = planef[2];
      planed[3] = planef[3];
      GE( ctx, glClipPlane (plane_num, planed) );
      break;
    }

  _cogl_matrix_stack_pop (modelview_stack);
}
Exemplo n.º 5
0
/* Reads back the contents of a texture by rendering it to the framebuffer
 * and reading back the resulting pixels.
 *
 * NB: Normally this approach isn't normally used since we can just use
 * glGetTexImage, but may be used as a fallback in some circumstances.
 */
gboolean
_cogl_texture_draw_and_read (CoglHandle   handle,
                             CoglBitmap  *target_bmp,
                             GLuint       target_gl_format,
                             GLuint       target_gl_type)
{
  int        bpp;
  CoglFramebuffer *framebuffer;
  int        viewport[4];
  CoglBitmap *alpha_bmp;
  CoglMatrixStack *projection_stack;
  CoglMatrixStack *modelview_stack;
  int target_width = _cogl_bitmap_get_width (target_bmp);
  int target_height = _cogl_bitmap_get_height (target_bmp);
  int target_rowstride = _cogl_bitmap_get_rowstride (target_bmp);

  _COGL_GET_CONTEXT (ctx, FALSE);

  bpp = _cogl_get_format_bpp (COGL_PIXEL_FORMAT_RGBA_8888);

  framebuffer = _cogl_get_draw_buffer ();
  /* Viewport needs to have some size and be inside the window for this */
  _cogl_framebuffer_get_viewport4fv (framebuffer, viewport);
  if (viewport[0] <  0 || viewport[1] <  0 ||
      viewport[2] <= 0 || viewport[3] <= 0)
    return FALSE;

  /* Setup orthographic projection into current viewport (0,0 in top-left
   * corner to draw the texture upside-down so we match the way cogl_read_pixels
   * works)
   */

  projection_stack = _cogl_framebuffer_get_projection_stack (framebuffer);
  _cogl_matrix_stack_push (projection_stack);
  _cogl_matrix_stack_load_identity (projection_stack);
  _cogl_matrix_stack_ortho (projection_stack,
                            0, (float)(viewport[2]),
                            (float)(viewport[3]), 0,
                            (float)(0),
                            (float)(100));

  modelview_stack = _cogl_framebuffer_get_modelview_stack (framebuffer);
  _cogl_matrix_stack_push (modelview_stack);
  _cogl_matrix_stack_load_identity (modelview_stack);

  /* Direct copy operation */

  if (ctx->texture_download_pipeline == COGL_INVALID_HANDLE)
    {
      ctx->texture_download_pipeline = cogl_pipeline_new ();
      cogl_pipeline_set_blend (ctx->texture_download_pipeline,
                               "RGBA = ADD (SRC_COLOR, 0)",
                               NULL);
    }

  cogl_push_source (ctx->texture_download_pipeline);

  cogl_pipeline_set_layer_texture (ctx->texture_download_pipeline, 0, handle);

  cogl_pipeline_set_layer_combine (ctx->texture_download_pipeline,
                                   0, /* layer */
                                   "RGBA = REPLACE (TEXTURE)",
                                   NULL);

  cogl_pipeline_set_layer_filters (ctx->texture_download_pipeline, 0,
                                   COGL_PIPELINE_FILTER_NEAREST,
                                   COGL_PIPELINE_FILTER_NEAREST);

  do_texture_draw_and_read (handle, target_bmp, viewport);

  /* Check whether texture has alpha and framebuffer not */
  /* FIXME: For some reason even if ALPHA_BITS is 8, the framebuffer
     still doesn't seem to have an alpha buffer. This might be just
     a PowerVR issue.
  GLint r_bits, g_bits, b_bits, a_bits;
  GE( glGetIntegerv (GL_ALPHA_BITS, &a_bits) );
  GE( glGetIntegerv (GL_RED_BITS, &r_bits) );
  GE( glGetIntegerv (GL_GREEN_BITS, &g_bits) );
  GE( glGetIntegerv (GL_BLUE_BITS, &b_bits) );
  printf ("R bits: %d\n", r_bits);
  printf ("G bits: %d\n", g_bits);
  printf ("B bits: %d\n", b_bits);
  printf ("A bits: %d\n", a_bits); */
  if ((cogl_texture_get_format (handle) & COGL_A_BIT)/* && a_bits == 0*/)
    {
      guint8 *srcdata;
      guint8 *dstdata;
      guint8 *srcpixel;
      guint8 *dstpixel;
      int     x,y;
      int     alpha_rowstride = bpp * target_width;

      if ((dstdata = _cogl_bitmap_map (target_bmp,
                                       COGL_BUFFER_ACCESS_WRITE,
                                       COGL_BUFFER_MAP_HINT_DISCARD)) == NULL)
        return FALSE;

      srcdata = g_malloc (alpha_rowstride * target_height);

      /* Create temp bitmap for alpha values */
      alpha_bmp = _cogl_bitmap_new_from_data (srcdata,
                                              COGL_PIXEL_FORMAT_RGBA_8888,
                                              target_width, target_height,
                                              alpha_rowstride,
                                              (CoglBitmapDestroyNotify) g_free,
                                              NULL);

      /* Draw alpha values into RGB channels */
      cogl_pipeline_set_layer_combine (ctx->texture_download_pipeline,
                                       0, /* layer */
                                       "RGBA = REPLACE (TEXTURE[A])",
                                       NULL);

      do_texture_draw_and_read (handle, alpha_bmp, viewport);

      /* Copy temp R to target A */

      for (y=0; y<target_height; ++y)
        {
          for (x=0; x<target_width; ++x)
            {
              srcpixel = srcdata + x*bpp;
              dstpixel = dstdata + x*bpp;
              dstpixel[3] = srcpixel[0];
            }
          srcdata += alpha_rowstride;
          dstdata += target_rowstride;
        }

      _cogl_bitmap_unmap (target_bmp);

      cogl_object_unref (alpha_bmp);
    }

  /* Restore old state */
  _cogl_matrix_stack_pop (modelview_stack);
  _cogl_matrix_stack_pop (projection_stack);

  /* restore the original pipeline */
  cogl_pop_source ();

  return TRUE;
}