logicsignal.cpp

   1 /*
   2  * This file is part of the sigrok project.
   3  *
   4  * Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #define GL_GLEXT_PROTOTYPES
  22 #include <GL/gl.h>
  23 #include <GL/glext.h>
  24
  25 #include <math.h>
  26
  27 #include "logicdata.h"
  28 #include "logicdatasnapshot.h"
  29 #include "logicsignal.h"
  30
  31 using namespace boost;
  32 using namespace std;
  33
  34 const float Log2 = logf(2.0f);
  35
  36 LogicSignal::LogicSignal(QString name, shared_ptr<LogicData> data,
  37         int probe_index) :
  38         Signal(name),
  39         _data(data),
  40         _probe_index(probe_index)
  41 {
  42         assert(_probe_index >= 0);
  43 }
  44
  45 void LogicSignal::paint(QGLWidget &widget, const QRect &rect,
  46         uint64_t scale, int64_t offset)
  47 {
  48         Point2F *vertex;
  49
  50         vector< pair<int64_t, bool> > edges;
  51
  52         assert(_data);
  53
  54         const queue< shared_ptr<LogicDataSnapshot> > &snapshots =
  55                 _data->get_snapshots();
  56         if(snapshots.empty())
  57                 return;
  58
  59         const shared_ptr<LogicDataSnapshot> &snapshot = snapshots.front();
  60
  61         const uint64_t samplerate = _data->get_samplerate();
  62         const int64_t start_time = _data->get_start_time();
  63         const float samples_per_pixel = samplerate * scale / 1e15f;
  64         const int64_t start = samplerate * (offset - start_time) /
  65                 1000000000000000ULL;
  66         const int64_t end = start + samples_per_pixel * rect.width();
  67         const int64_t quantization_length = 1LL << (int64_t)floorf(
  68                 max(logf(samples_per_pixel / Log2), 0.0f));
  69
  70         snapshot->get_subsampled_edges(edges, start, end,
  71                 quantization_length, _probe_index);
  72
  73         // Paint the edges
  74         const unsigned int edge_point_count = (edges.size() - 2) * 2;
  75         Point2F *const edge_points = new Point2F[edge_point_count];
  76         vertex = edge_points;
  77
  78         for(vector<LogicDataSnapshot::EdgePair>::const_iterator i = edges.begin() + 1;
  79             i != edges.end() - 1; i++)
  80         {
  81                 const int x = (int)((*i).first / samples_per_pixel) +
  82                         rect.left();
  83
  84                 vertex->x = x, vertex->y = 10 + rect.top() - 1;
  85                 vertex++;
  86                 vertex->x = x, vertex->y = 40 + rect.top();
  87                 vertex++;
  88         }
  89
  90         glColor3f(0,0,1);
  91         paint_lines(edge_points, edge_point_count);
  92         delete[] edge_points;
  93
  94         // Paint the caps
  95         const unsigned int cap_point_count = (edges.size() - 1) * 2;
  96         Point2F *const cap_points = new Point2F[cap_point_count];
  97         vertex = cap_points;
  98
  99         for(vector<LogicDataSnapshot::EdgePair>::const_iterator i = edges.begin();
 100             i != (edges.end() - 1); i++)
 101         {
 102                 const int y = ((*i).second ? 10 : 40) + rect.top();
 103
 104                 vertex->x = (int)((*i).first / samples_per_pixel) +
 105                         rect.left() - 1;
 106                 vertex->y = y;
 107                 vertex++;
 108
 109                 vertex->x = (int)((*(i+1)).first / samples_per_pixel) +
 110                         rect.left();
 111                 vertex->y = y;
 112                 vertex++;
 113         }
 114
 115         glColor3f(0,0,1);
 116         paint_lines(cap_points, cap_point_count);
 117         delete[] cap_points;
 118 }
 119
 120 void LogicSignal::paint_lines(Point2F *points, int count)
 121 {
 122         GLuint vbo_id;
 123
 124         assert(points);
 125
 126         glGenBuffers(1, &vbo_id);
 127         glBindBuffer(GL_ARRAY_BUFFER, vbo_id);
 128
 129         const unsigned int vbo_length = count * sizeof(Point2F);
 130         glBufferData(GL_ARRAY_BUFFER, vbo_length, NULL, GL_STATIC_DRAW);
 131         glBufferSubData(GL_ARRAY_BUFFER, 0, vbo_length, points);
 132
 133         glBindBuffer(GL_ARRAY_BUFFER, vbo_id);
 134
 135         glVertexPointer(2, GL_FLOAT, sizeof(Point2F), 0);
 136
 137         glEnableClientState(GL_VERTEX_ARRAY);
 138         glDrawArrays(GL_LINES,  0,  count);
 139         glDisableClientState(GL_VERTEX_ARRAY);
 140
 141         glDeleteBuffers(1, &vbo_id);
 142 }