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);
}
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;
}
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);
}
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);
}
/* 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;
}
