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livetrax/libs/surfaces/push2/canvas.cc
2016-09-27 14:59:31 -05:00

220 lines
5.2 KiB
C++

/*
Copyright (C) 2016 Paul Davis
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <cairomm/region.h>
#include <cairomm/surface.h>
#include <cairomm/context.h>
#include "pbd/compose.h"
#include "ardour/debug.h"
#include "canvas.h"
#include "layout.h"
#include "push2.h"
using namespace ArdourCanvas;
using namespace ArdourSurface;
using namespace PBD;
const int Push2Canvas::pixels_per_row = 1024;
Push2Canvas::Push2Canvas (Push2& pr, int c, int r)
: p2 (pr)
, _cols (c)
, _rows (r)
, frame_buffer (Cairo::ImageSurface::create (Cairo::FORMAT_ARGB32, _cols, _rows))
{
context = Cairo::Context::create (frame_buffer);
expose_region = Cairo::Region::create ();
device_frame_buffer = new uint16_t[pixel_area()];
memset (device_frame_buffer, 0, sizeof (uint16_t) * pixel_area());
frame_header[0] = 0xef;
frame_header[1] = 0xcd;
frame_header[2] = 0xab;
frame_header[3] = 0x89;
memset (&frame_header[4], 0, 12);
}
Push2Canvas::~Push2Canvas ()
{
delete [] device_frame_buffer;
device_frame_buffer = 0;
}
bool
Push2Canvas::vblank ()
{
/* re-render dirty areas, if any */
if (expose ()) {
DEBUG_TRACE (DEBUG::Push2, "re-blit to device frame buffer\n");
/* something rendered, update device_frame_buffer */
blit_to_device_frame_buffer ();
}
int transferred = 0;
const int timeout_msecs = 1000;
int err;
/* transfer to device */
if ((err = libusb_bulk_transfer (p2.usb_handle(), 0x01, frame_header, sizeof (frame_header), &transferred, timeout_msecs))) {
return false;
}
if ((err = libusb_bulk_transfer (p2.usb_handle(), 0x01, (uint8_t*) device_frame_buffer, 2 * pixel_area (), &transferred, timeout_msecs))) {
return false;
}
return true;
}
void
Push2Canvas::request_redraw ()
{
request_redraw (Rect (0, 0, _cols, _rows));
}
void
Push2Canvas::request_redraw (Rect const & r)
{
Cairo::RectangleInt cr;
cr.x = r.x0;
cr.y = r.y0;
cr.width = r.width();
cr.height = r.height();
DEBUG_TRACE (DEBUG::Push2, string_compose ("invalidate rect %1\n", r));
expose_region->do_union (cr);
/* next vblank will redraw */
}
bool
Push2Canvas::expose ()
{
if (expose_region->empty()) {
return false; /* nothing drawn */
}
/* set up clipping */
const int nrects = expose_region->get_num_rectangles ();
DEBUG_TRACE (DEBUG::Push2, string_compose ("expose with %1 rects\n", nrects));
for (int n = 0; n < nrects; ++n) {
Cairo::RectangleInt r = expose_region->get_rectangle (n);
context->rectangle (r.x, r.y, r.width, r.height);
}
context->clip ();
Push2Layout* layout = p2.current_layout();
if (layout) {
Cairo::RectangleInt r = expose_region->get_extents();
Rect rr (r.x, r.y, r.x + r.width, r.y + r.height);
DEBUG_TRACE (DEBUG::Push2, string_compose ("render layout with %1\n", rr));
layout->render (Rect (r.x, r.y, r.x + r.width, r.y + r.height), context);
}
context->reset_clip ();
/* why is there no "reset()" method for Cairo::Region? */
expose_region = Cairo::Region::create ();
return true;
}
/** render host-side frame buffer (a Cairo ImageSurface) to the current
* device-side frame buffer. The device frame buffer will be pushed to the
* device on the next call to vblank()
*/
int
Push2Canvas::blit_to_device_frame_buffer ()
{
/* ensure that all drawing has been done before we fetch pixel data */
frame_buffer->flush ();
const int stride = 3840; /* bytes per row for Cairo::FORMAT_ARGB32 */
const uint8_t* data = frame_buffer->get_data ();
/* fill frame buffer (320kB) */
uint16_t* fb = (uint16_t*) device_frame_buffer;
for (int row = 0; row < _rows; ++row) {
const uint8_t* dp = data + row * stride;
for (int col = 0; col < _cols; ++col) {
/* fetch r, g, b (range 0..255). Ignore alpha */
const int r = (*((const uint32_t*)dp) >> 16) & 0xff;
const int g = (*((const uint32_t*)dp) >> 8) & 0xff;
const int b = *((const uint32_t*)dp) & 0xff;
/* convert to 5 bits, 6 bits, 5 bits, respectively */
/* generate 16 bit BGB565 value */
*fb++ = (r >> 3) | ((g & 0xfc) << 3) | ((b & 0xf8) << 8);
/* the push2 docs state that we should xor the pixel
* data. Doing so doesn't work correctly, and not doing
* so seems to work fine (colors roughly match intended
* values).
*/
dp += 4;
}
/* skip 128 bytes to next line. This is filler, used to avoid line borders occuring in the middle of 512
byte USB buffers
*/
fb += 64; /* 128 bytes = 64 int16_t */
}
return 0;
}
void
Push2Canvas::request_size (Duple)
{
/* fixed size canvas */
}
Rect
Push2Canvas::visible_area () const
{
/* may need to get more sophisticated once we do scrolling */
return Rect (0, 0, 960, 160);
}