gtk/gdk/gdkgl.c
2014-10-30 12:43:03 +01:00

495 lines
17 KiB
C

/* GDK - The GIMP Drawing Kit
* Copyright (C) 2014 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "gdkcairo.h"
#include "gdkglcontextprivate.h"
#include "gdkinternals.h"
#include <epoxy/gl.h>
#include <math.h>
static cairo_user_data_key_t direct_key;
void
gdk_cairo_surface_mark_as_direct (cairo_surface_t *surface,
GdkWindow *window)
{
cairo_surface_set_user_data (surface, &direct_key,
g_object_ref (window), g_object_unref);
}
/* x,y,width,height describes a rectangle in the gl render buffer
coordinate space, and its top left corner is drawn at the current
position according to the cairo translation. */
/**
* gdk_cairo_draw_from_gl:
* @cr: a cairo context
* @window: The window we're rendering for (not necessarily into)
* @source: The GL ID of the source buffer
* @source_type: The type of the @source
* @buffer_scale: The scale-factor that the @source buffer is allocated for
* @x: The source x position in @source to start copying from in GL coordinates
* @y: The source y position in @source to start copying from in GL coordinates
* @width: The width of the region to draw
* @height: The height of the region to draw
*
* This is the main way to draw GL content in GTK+. It takes a render buffer ID
* (@source_type == #GL_RENDERBUFFER) or a texture id (@source_type == #GL_TEXTURE)
* and draws it onto @cr with an OVER operation, respecting the current clip.
* The top left corner of the rectangle specified by @x, @y, @width and @height
* will be drawn at the current (0,0) position of the cairo_t.
*
* This will work for *all* cairo_t, as long as @window is realized, but the
* fallback implementation that reads back the pixels from the buffer may be
* used in the general case. In the case of direct drawing to a window with
* no special effects applied to @cr it will however use a more efficient
* approach.
*
* For #GL_RENDERBUFFER the code will always fall back to software for buffers
* with alpha components, so make sure you use #GL_TEXTURE if using alpha.
*
* Since: 3.16
*/
void
gdk_cairo_draw_from_gl (cairo_t *cr,
GdkWindow *window,
int source,
int source_type,
int buffer_scale,
int x,
int y,
int width,
int height)
{
GdkGLContext *context;
cairo_surface_t *image;
cairo_matrix_t matrix;
int dx, dy, window_scale;
gboolean trivial_transform;
cairo_surface_t *group_target;
GdkWindow *direct_window, *impl_window;
GLuint framebuffer;
GLint alpha_size = 0;
cairo_region_t *clip_region;
impl_window = window->impl_window;
window_scale = gdk_window_get_scale_factor (impl_window);
context = gdk_window_get_paint_gl_context (window, NULL);
if (context == NULL)
{
g_warning ("gdk_cairo_draw_gl_render_buffer failed - no paint context");
return;
}
clip_region = gdk_cairo_region_from_clip (cr);
gdk_gl_context_make_current (context);
glGenFramebuffersEXT (1, &framebuffer);
glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, framebuffer);
if (source_type == GL_RENDERBUFFER)
{
glGetRenderbufferParameteriv (GL_RENDERBUFFER, GL_RENDERBUFFER_ALPHA_SIZE, &alpha_size);
glBindRenderbufferEXT (GL_RENDERBUFFER_EXT, source);
glFramebufferRenderbufferEXT (GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
GL_RENDERBUFFER_EXT, source);
glBindFramebufferEXT (GL_DRAW_FRAMEBUFFER_EXT, 0);
}
else if (source_type == GL_TEXTURE)
{
glBindTexture (GL_TEXTURE_2D, source);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_ALPHA_SIZE, &alpha_size);
glBindFramebufferEXT (GL_DRAW_FRAMEBUFFER_EXT, 0);
}
else
{
g_warning ("Unsupported gl source type %d\n", source_type);
return;
}
group_target = cairo_get_group_target (cr);
direct_window = cairo_surface_get_user_data (group_target, &direct_key);
cairo_get_matrix (cr, &matrix);
dx = matrix.x0;
dy = matrix.y0;
/* Trivial == integer-only translation */
trivial_transform =
(double)dx == matrix.x0 && (double)dy == matrix.y0 &&
matrix.xx == 1.0 && matrix.xy == 0.0 &&
matrix.yx == 0.0 && matrix.yy == 1.0;
/* For direct paint of non-alpha renderbuffer, we can
just do a bitblit */
if (source_type == GL_RENDERBUFFER &&
alpha_size == 0 &&
direct_window != NULL &&
direct_window->current_paint.use_gl &&
trivial_transform &&
clip_region != NULL)
{
int window_height;
int i;
/* Translate to impl coords */
cairo_region_translate (clip_region, dx, dy);
glEnable (GL_SCISSOR_TEST);
window_height = gdk_window_get_height (impl_window);
glDrawBuffer (GL_BACK);
#define FLIP_Y(_y) (window_height*window_scale - (_y))
for (i = 0; i < cairo_region_num_rectangles (clip_region); i++)
{
cairo_rectangle_int_t clip_rect, dest;
cairo_region_get_rectangle (clip_region, i, &clip_rect);
clip_rect.x *= window_scale;
clip_rect.y *= window_scale;
clip_rect.width *= window_scale;
clip_rect.height *= window_scale;
glScissor (clip_rect.x, FLIP_Y (clip_rect.y + clip_rect.height),
clip_rect.width, clip_rect.height);
dest.x = dx * window_scale;
dest.y = dy * window_scale;
dest.width = width * window_scale / buffer_scale;
dest.height = height * window_scale / buffer_scale;
if (gdk_rectangle_intersect (&clip_rect, &dest, &dest))
{
int clipped_src_x = x + (dest.x - dx * window_scale);
int clipped_src_y = y + (height - dest.height - (dest.y - dy * window_scale));
glBlitFramebufferEXT(clipped_src_x, clipped_src_y,
(clipped_src_x + dest.width), (clipped_src_y + dest.height),
dest.x, FLIP_Y(dest.y + dest.height),
dest.x + dest.width, FLIP_Y(dest.y),
GL_COLOR_BUFFER_BIT, GL_NEAREST);
if (impl_window->current_paint.flushed_region)
{
cairo_rectangle_int_t flushed_rect;
flushed_rect.x = dest.x / window_scale;
flushed_rect.y = dest.y / window_scale;
flushed_rect.width = (dest.x + dest.width + window_scale - 1) / window_scale - flushed_rect.x;
flushed_rect.height = (dest.y + dest.height + window_scale - 1) / window_scale - flushed_rect.y;
cairo_region_union_rectangle (impl_window->current_paint.flushed_region,
&flushed_rect);
cairo_region_subtract_rectangle (impl_window->current_paint.need_blend_region,
&flushed_rect);
}
}
}
glDisable (GL_SCISSOR_TEST);
#undef FLIP_Y
}
/* For direct paint of alpha or non-alpha textures we can use texturing */
else if (source_type == GL_TEXTURE &&
direct_window != NULL &&
direct_window->current_paint.use_gl &&
trivial_transform &&
clip_region != NULL)
{
int window_height;
GLint texture_width;
GLint texture_height;
int i;
/* Translate to impl coords */
cairo_region_translate (clip_region, dx, dy);
if (alpha_size != 0)
{
cairo_region_t *opaque_region, *blend_region;
opaque_region = cairo_region_copy (clip_region);
cairo_region_subtract (opaque_region, impl_window->current_paint.flushed_region);
cairo_region_subtract (opaque_region, impl_window->current_paint.need_blend_region);
if (!cairo_region_is_empty (opaque_region))
gdk_gl_texture_from_surface (impl_window->current_paint.surface,
opaque_region);
blend_region = cairo_region_copy (clip_region);
cairo_region_intersect (blend_region, impl_window->current_paint.need_blend_region);
glEnable (GL_BLEND);
if (!cairo_region_is_empty (blend_region))
gdk_gl_texture_from_surface (impl_window->current_paint.surface,
blend_region);
cairo_region_destroy (opaque_region);
cairo_region_destroy (blend_region);
}
glBindTexture (GL_TEXTURE_2D, source);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_WIDTH, &texture_width);
glGetTexLevelParameteriv (GL_TEXTURE_2D, 0, GL_TEXTURE_HEIGHT, &texture_height);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glFramebufferTexture2DEXT (GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,
GL_TEXTURE_2D, source, 0);
glEnable (GL_SCISSOR_TEST);
glEnable (GL_TEXTURE_2D);
window_height = gdk_window_get_height (impl_window);
#define FLIP_Y(_y) (window_height*window_scale - (_y))
for (i = 0; i < cairo_region_num_rectangles (clip_region); i++)
{
cairo_rectangle_int_t clip_rect, dest;
cairo_region_get_rectangle (clip_region, i, &clip_rect);
clip_rect.x *= window_scale;
clip_rect.y *= window_scale;
clip_rect.width *= window_scale;
clip_rect.height *= window_scale;
glScissor (clip_rect.x, FLIP_Y (clip_rect.y + clip_rect.height),
clip_rect.width, clip_rect.height);
dest.x = dx * window_scale;
dest.y = dy * window_scale;
dest.width = width * window_scale / buffer_scale;
dest.height = height * window_scale / buffer_scale;
if (gdk_rectangle_intersect (&clip_rect, &dest, &dest))
{
int clipped_src_x = x + (dest.x - dx * window_scale);
int clipped_src_y = y + (height - dest.height - (dest.y - dy * window_scale));
glBegin (GL_QUADS);
glTexCoord2f (clipped_src_x / (float)texture_width, clipped_src_y / (float)texture_height);
glVertex2f (dest.x, FLIP_Y(dest.y + dest.height));
glTexCoord2f ((clipped_src_x + dest.width) / (float)texture_width, clipped_src_y / (float)texture_height);
glVertex2f (dest.x + dest.width, FLIP_Y(dest.y + dest.height));
glTexCoord2f ((clipped_src_x + dest.width) / (float)texture_width, (clipped_src_y + dest.height) / (float)texture_height);
glVertex2f (dest.x + dest.width, FLIP_Y(dest.y));
glTexCoord2f (clipped_src_x / (float)texture_width, (clipped_src_y + dest.height) / (float)texture_height);
glVertex2f (dest.x, FLIP_Y(dest.y));
glEnd();
if (impl_window->current_paint.flushed_region)
{
cairo_rectangle_int_t flushed_rect;
flushed_rect.x = dest.x / window_scale;
flushed_rect.y = dest.y / window_scale;
flushed_rect.width = (dest.x + dest.width + window_scale - 1) / window_scale - flushed_rect.x;
flushed_rect.height = (dest.y + dest.height + window_scale - 1) / window_scale - flushed_rect.y;
cairo_region_union_rectangle (impl_window->current_paint.flushed_region,
&flushed_rect);
cairo_region_subtract_rectangle (impl_window->current_paint.need_blend_region,
&flushed_rect);
}
}
}
if (alpha_size != 0)
glDisable (GL_BLEND);
glDisable (GL_TEXTURE_2D);
glDisable (GL_SCISSOR_TEST);
#undef FLIP_Y
}
else
{
/* Software fallback */
/* TODO: avoid reading back non-required data due to dest clip */
image = cairo_surface_create_similar_image (cairo_get_target (cr),
(alpha_size == 0) ? CAIRO_FORMAT_RGB24 : CAIRO_FORMAT_ARGB32,
width, height);
#ifdef HAVE_CAIRO_SURFACE_SET_DEVICE_SCALE
cairo_surface_set_device_scale (image, buffer_scale, buffer_scale);
#endif
glPixelStorei (GL_PACK_ALIGNMENT, 4);
glPixelStorei (GL_PACK_ROW_LENGTH, cairo_image_surface_get_stride (image) / 4);
glReadPixels (x, y, width, height, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV,
cairo_image_surface_get_data (image));
glPixelStorei (GL_PACK_ROW_LENGTH, 0);
cairo_surface_mark_dirty (image);
/* Invert due to opengl having different origin */
cairo_scale (cr, 1, -1);
cairo_translate (cr, 0, -height / buffer_scale);
cairo_set_source_surface (cr, image, 0, 0);
cairo_set_operator (cr, CAIRO_OPERATOR_OVER);
cairo_paint (cr);
cairo_surface_destroy (image);
}
glDrawBuffer (GL_BACK);
glReadBuffer(GL_BACK);
glBindFramebufferEXT (GL_FRAMEBUFFER_EXT, 0);
glDeleteFramebuffersEXT (1, &framebuffer);
if (clip_region)
cairo_region_destroy (clip_region);
}
void
gdk_gl_texture_from_surface (cairo_surface_t *surface,
cairo_region_t *region)
{
GdkGLContext *current;
cairo_surface_t *image;
double device_x_offset, device_y_offset;
cairo_rectangle_int_t rect, e;
int n_rects, i;
GdkWindow *window;
int window_height;
unsigned int texture_id;
int window_scale;
double sx, sy;
float umax, vmax;
gboolean use_texture_rectangle;
guint target;
current = gdk_gl_context_get_current ();
if (current &&
GDK_GL_CONTEXT_GET_CLASS (current)->texture_from_surface &&
GDK_GL_CONTEXT_GET_CLASS (current)->texture_from_surface (current, surface, region))
return;
/* Software fallback */
use_texture_rectangle = gdk_gl_context_use_texture_rectangle (current);
window = gdk_gl_context_get_window (current);
window_scale = gdk_window_get_scale_factor (window);
window_height = gdk_window_get_height (window);
sx = sy = 1;
#ifdef HAVE_CAIRO_SURFACE_SET_DEVICE_SCALE
cairo_surface_get_device_scale (window->current_paint.surface, &sx, &sy);
#endif
cairo_surface_get_device_offset (surface,
&device_x_offset, &device_y_offset);
glGenTextures (1, &texture_id);
if (use_texture_rectangle)
target = GL_TEXTURE_RECTANGLE_ARB;
else
target = GL_TEXTURE_2D;
glBindTexture (target, texture_id);
glEnable (target);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
n_rects = cairo_region_num_rectangles (region);
for (i = 0; i < n_rects; i++)
{
cairo_region_get_rectangle (region, i, &rect);
glScissor (rect.x * window_scale, (window_height - rect.y - rect.height) * window_scale,
rect.width * window_scale, rect.height * window_scale);
e = rect;
e.x *= sx;
e.y *= sy;
e.x += (int)device_x_offset;
e.y += (int)device_y_offset;
e.width *= sx;
e.height *= sy;
image = cairo_surface_map_to_image (surface, &e);
glPixelStorei (GL_UNPACK_ALIGNMENT, 4);
glPixelStorei (GL_UNPACK_ROW_LENGTH, cairo_image_surface_get_stride (image)/4);
glTexImage2D (target, 0, 4, e.width, e.height, 0, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV,
cairo_image_surface_get_data (image));
glPixelStorei (GL_UNPACK_ROW_LENGTH, 0);
cairo_surface_unmap_image (surface, image);
#define FLIP_Y(_y) (window_height - (_y))
if (use_texture_rectangle)
{
umax = rect.width * sx;
vmax = rect.height * sy;
}
else
{
umax = 1.0;
vmax = 1.0;
}
glBegin (GL_QUADS);
glTexCoord2f (0, vmax);
glVertex2f (rect.x * window_scale, FLIP_Y(rect.y + rect.height) * window_scale);
glTexCoord2f (umax, vmax);
glVertex2f ((rect.x + rect.width) * window_scale, FLIP_Y(rect.y + rect.height) * window_scale);
glTexCoord2f (umax, 0);
glVertex2f ((rect.x + rect.width) * window_scale, FLIP_Y(rect.y) * window_scale);
glTexCoord2f (0, 0);
glVertex2f (rect.x * window_scale, FLIP_Y(rect.y) * window_scale);
glEnd();
}
glDisable (target);
glDeleteTextures (1, &texture_id);
}