]> sigrok.org Git - pulseview.git/blobdiff - logicdatasnapshot.cpp
Corrected project name in header comments
[pulseview.git] / logicdatasnapshot.cpp
index 5301abf59d04d6920892a5b6bfaa143ebf04c9ad..62d8a90bdc184ee5c9a50ada94d6674b6cfcca57 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * This file is part of the sigrok project.
+ * This file is part of the PulseView project.
  *
  * Copyright (C) 2012 Joel Holdsworth <joel@airwebreathe.org.uk>
  *
@@ -22,6 +22,7 @@
 
 #include <assert.h>
 #include <string.h>
+#include <stdlib.h>
 #include <math.h>
 
 #include <boost/foreach.hpp>
@@ -55,7 +56,6 @@ void LogicDataSnapshot::append_payload(
 {
        assert(_unit_size == logic.unitsize);
 
-       const uint64_t prev_length = _data_length;
        append_data(logic.data, logic.length);
 
        // Generate the first mip-map from the data
@@ -84,7 +84,7 @@ void LogicDataSnapshot::append_payload_to_mipmap()
 
        // Expand the data buffer to fit the new samples
        prev_length = m0.length;
-       m0.length = _data_length / MipMapScaleFactor;
+       m0.length = _sample_count / MipMapScaleFactor;
 
        // Break off if there are no new samples to compute
        if(m0.length == prev_length)
@@ -160,7 +160,7 @@ void LogicDataSnapshot::append_payload_to_mipmap()
 uint64_t LogicDataSnapshot::get_sample(uint64_t index) const
 {
        assert(_data);
-       assert(index >= 0 && index < _data_length);
+       assert(index >= 0 && index < _sample_count);
 
        return *(uint64_t*)((uint8_t*)_data + index * _unit_size);
 }
@@ -170,8 +170,10 @@ void LogicDataSnapshot::get_subsampled_edges(
        int64_t start, int64_t end,
        float min_length, int sig_index)
 {
-       int64_t index;
+       int64_t index = start;
        int level;
+       bool last_sample;
+       bool fast_forward;
 
        assert(start >= 0);
        assert(end <= get_sample_count());
@@ -180,35 +182,41 @@ void LogicDataSnapshot::get_subsampled_edges(
        assert(sig_index >= 0);
        assert(sig_index < SR_MAX_NUM_PROBES);
 
+       const int64_t block_length = (int64_t)max(min_length, 1.0f);
        const int min_level = max((int)floorf(logf(min_length) /
                LogMipMapScaleFactor) - 1, 0);
-       const uint64_t sig_mask = 1 << sig_index;
+       const uint64_t sig_mask = 1ULL << sig_index;
 
-       // Add the initial state
-       bool last_sample = get_sample(start) & sig_mask;
-       edges.push_back(pair<int64_t, bool>(start, last_sample));
+       // Store the initial state
+       last_sample = (get_sample(start) & sig_mask) != 0;
+       edges.push_back(pair<int64_t, bool>(index++, last_sample));
 
-       index = start + 1;
-       for(index = start + 1; index < end;)
+       while(index + block_length <= end)
        {
+               //----- Continue to search -----//
                level = min_level;
+               fast_forward = true;
 
                if(min_length < MipMapScaleFactor)
                {
                        // Search individual samples up to the beginning of
                        // the next first level mip map block
-                       const uint64_t final_sample = min(end,
+                       const uint64_t final_index = min(end,
                                pow2_ceil(index, MipMapScalePower));
 
                        for(index;
-                               index < final_sample &&
+                               index < final_index &&
                                (index & ~(~0 << MipMapScalePower)) != 0;
                                index++)
                        {
                                const bool sample =
                                        (get_sample(index) & sig_mask) != 0;
-                               if(sample != last_sample)
+
+                               // If there was a change we cannot fast forward
+                               if(sample != last_sample) {
+                                       fast_forward = false;
                                        break;
+                               }
                        }
                }
                else
@@ -219,103 +227,112 @@ void LogicDataSnapshot::get_subsampled_edges(
                        const int min_level_scale_power =
                                (level + 1) * MipMapScalePower;
                        index = pow2_ceil(index, min_level_scale_power);
-               }
-
-               // Slide right and zoom out at the beginnings of mip-map
-               // blocks until we encounter a change
-               while(1)
-               {
-                       const int level_scale_power =
-                               (level + 1) * MipMapScalePower;
-                       const uint64_t offset = index >> level_scale_power;
-                       assert(offset >= 0);
-
-                       // Check if we reached the last block at this level,
-                       // or if there was a change in this block
-                       if(offset >= _mip_map[level].length ||
-                               (*(uint64_t*)((uint8_t*)_mip_map[level].data +
-                               _unit_size * offset) & sig_mask))
+                       if(index >= end)
                                break;
 
-                       if((offset & ~(~0 << MipMapScalePower)) == 0)
-                       {
-                               // If we are now at the beginning of a higher
-                               // level mip-map block ascend one level
-                               if(!_mip_map[level + 1].data)
-                                       break;
-
-                               level++;
-                       }
-                       else
-                       {
-                               // Slide right to the beginning of the next mip
-                               // map block
-                               index = pow2_ceil(index, level_scale_power);
-                       }
+                       // We can fast forward only if there was no change
+                       const bool sample =
+                               (get_sample(index) & sig_mask) != 0;
+                       fast_forward = last_sample == sample;
                }
 
-               // Zoom in, and slide right until we encounter a change,
-               // and repeat until we reach min_level
-               while(1)
-               {
-                       assert(_mip_map[level].data);
-
-                       const int level_scale_power =
-                               (level + 1) * MipMapScalePower;
-                       const uint64_t offset = index >> level_scale_power;
-                       assert(offset >= 0);
-
-                       // Check if we reached the last block at this level,
-                       // or if there was a change in this block
-                       if(offset >= _mip_map[level].length ||
-                               (*(uint64_t*)((uint8_t*)_mip_map[level].data +
-                               _unit_size * offset) & sig_mask))
-                       {
-                               // Zoom in unless we reached the minimum zoom
-                               if(level == min_level)
+               if(fast_forward) {
+
+                       // Fast forward: This involves zooming out to higher
+                       // levels of the mip map searching for changes, then
+                       // zooming in on them to find the point where the edge
+                       // begins.
+
+                       // Slide right and zoom out at the beginnings of mip-map
+                       // blocks until we encounter a change
+                       while(1) {
+                               const int level_scale_power =
+                                       (level + 1) * MipMapScalePower;
+                               const uint64_t offset =
+                                       index >> level_scale_power;
+                               assert(offset >= 0);
+
+                               // Check if we reached the last block at this
+                               // level, or if there was a change in this block
+                               if(offset >= _mip_map[level].length ||
+                                       (get_subsample(level, offset) &
+                                               sig_mask))
                                        break;
 
-                               level--;
+                               if((offset & ~(~0 << MipMapScalePower)) == 0) {
+                                       // If we are now at the beginning of a
+                                       // higher level mip-map block ascend one
+                                       // level
+                                       if(level + 1 >= ScaleStepCount ||
+                                               !_mip_map[level + 1].data)
+                                               break;
+
+                                       level++;
+                               } else {
+                                       // Slide right to the beginning of the
+                                       // next mip map block
+                                       index = pow2_ceil(index + 1,
+                                               level_scale_power);
+                               }
                        }
-                       else
-                       {
-                               // Slide right to the beginning of the next mip map block
-                               index = pow2_ceil(index, level_scale_power);
+
+                       // Zoom in, and slide right until we encounter a change,
+                       // and repeat until we reach min_level
+                       while(1) {
+                               assert(_mip_map[level].data);
+
+                               const int level_scale_power =
+                                       (level + 1) * MipMapScalePower;
+                               const uint64_t offset =
+                                       index >> level_scale_power;
+                               assert(offset >= 0);
+
+                               // Check if we reached the last block at this
+                               // level, or if there was a change in this block
+                               if(offset >= _mip_map[level].length ||
+                                       (get_subsample(level, offset) &
+                                               sig_mask)) {
+                                       // Zoom in unless we reached the minimum
+                                       // zoom
+                                       if(level == min_level)
+                                               break;
+
+                                       level--;
+                               } else {
+                                       // Slide right to the beginning of the
+                                       // next mip map block
+                                       index = pow2_ceil(index + 1,
+                                               level_scale_power);
+                               }
                        }
-               }
 
-               // If individual samples within the limit of resolution,
-               // do a linear search for the next transition within the block
-               if(min_length < MipMapScaleFactor)
-               {
-                       for(index; index < end; index++)
-                       {
-                               const bool sample =
-                                       (get_sample(index) & sig_mask) != 0;
-                               if(sample != last_sample)
-                                       break;
+                       // If individual samples within the limit of resolution,
+                       // do a linear search for the next transition within the
+                       // block
+                       if(min_length < MipMapScaleFactor) {
+                               for(index; index < end; index++) {
+                                       const bool sample = (get_sample(index) &
+                                               sig_mask) != 0;
+                                       if(sample != last_sample)
+                                               break;
+                               }
                        }
                }
 
-               if(index < end)
-               {
-                       // Take the last sample of the quanization block
-                       const int64_t block_length = (int64_t)max(min_length, 1.0f);
-                       const int64_t rem = index % block_length;
-                       const int64_t final_index = min(index + (rem == 0 ? 0 :
-                               block_length - rem), end);
-
-                       // Store the final state
-                       const bool final_sample = get_sample(final_index) & sig_mask;
-                       edges.push_back(pair<int64_t, bool>(
-                               final_index, final_sample));
-
-                       // Continue to sample
-                       index = final_index;
-                       last_sample = final_sample;
-
-                       index++;
-               }
+               //----- Store the edge -----//
+
+               // Take the last sample of the quanization block
+               const int64_t final_index = index + block_length;
+               if(index + block_length > end)
+                       break;
+
+               // Store the final state
+               const bool final_sample =
+                       (get_sample(final_index - 1) & sig_mask) != 0;
+               edges.push_back(pair<int64_t, bool>(index, final_sample));
+
+               index = final_index;
+               last_sample = final_sample;
        }
 
        // Add the final state
@@ -323,6 +340,14 @@ void LogicDataSnapshot::get_subsampled_edges(
                get_sample(end) & sig_mask));
 }
 
+uint64_t LogicDataSnapshot::get_subsample(int level, uint64_t offset) const
+{
+       assert(level >= 0);
+       assert(_mip_map[level].data);
+       return *(uint64_t*)((uint8_t*)_mip_map[level].data +
+               _unit_size * offset);
+}
+
 int64_t LogicDataSnapshot::pow2_ceil(int64_t x, unsigned int power)
 {
        const int64_t p = 1 << power;