Client downsamples line plots automatically

2 files changed, 57 insertions, 7 deletions

diff --git a/core/client.cpp b/core/client.cpp
index ba0f3d6..cf85b27 100644
--- a/core/client.cpp
+++ b/core/client.cpp
@@ -342,6 +342,8 @@ std::vector<float> g_plot_cells_bottom;
 std::vector<bool> g_plots_covered;
 Plot *g_plot_selected;
 Plot *g_plot_hovered;
+int g_plot_stride;
+int g_downsampled_trace_len;
 int g_plot_cols = 2;
 size_t g_plot_col_selected;
 size_t g_plot_row_selected;
@@ -538,11 +540,12 @@ void PlotLines::render_internal(const ImVec2 &frame_size) {
     (void)frame_size;
 
     ImS64 *x = g_trace_map[g_x_axes[g_x_axis]]->start();
+    ImPlotSpec spec = ImPlotSpec(ImPlotProp_Stride, sizeof(ImS64) * g_plot_stride);
 
     for (auto &trace : m_trace_keys) {
         TraceNamed<ImS64> *trace_obj = g_trace_map[trace];
         ImS64 *y = trace_obj->start();
-        ImPlot::PlotLine(trace_obj->get_label(), x, y, g_trace_len);
+        ImPlot::PlotLine(trace_obj->get_label(), x, y, g_downsampled_trace_len, spec);
     }
 }
 
@@ -636,12 +639,13 @@ void PlotStacked::render_internal(const ImVec2 &frame_size) {
         assert(m_trace_states[i] == GImPlot->CurrentPlot->Items.GetLegendItem(i)->Show);
 
         if (m_trace_states[i]) {
-            ImPlotSpec spec = ImPlotSpec(ImPlotProp_FillAlpha, GImPlot->CurrentPlot->Items.GetLegendItem(i)->LegendHovered ? 1.f : 0.9f);
+            bool hovered = GImPlot->CurrentPlot->Items.GetLegendItem(i)->LegendHovered;
+            ImPlotSpec spec = ImPlotSpec(ImPlotProp_FillAlpha, hovered ? 1.f : 0.9f, ImPlotProp_Stride, sizeof(double) * g_plot_stride);
             const char *trace_name = g_trace_map[m_trace_keys[i]]->get_label();
             Trace<double> *current_trace = &m_trace_normals[i];
-            ImPlot::PlotShaded(trace_name, g_x_axis_double.start(), prev_trace->start(), current_trace->start(), g_trace_len, spec);
-            ImPlot::PlotLine(trace_name, g_x_axis_double.start(), prev_trace->start(), g_trace_len);
-            ImPlot::PlotLine(trace_name, g_x_axis_double.start(), current_trace->start(), g_trace_len);
+            ImPlot::PlotShaded(trace_name, g_x_axis_double.start(), prev_trace->start(), current_trace->start(), g_downsampled_trace_len, spec);
+            ImPlot::PlotLine(trace_name, g_x_axis_double.start(), prev_trace->start(), g_downsampled_trace_len, spec);
+            if (hovered) ImPlot::PlotLine(trace_name, g_x_axis_double.start(), current_trace->start(), g_downsampled_trace_len, spec);
             prev_trace = current_trace;
         }
     }
@@ -800,6 +804,30 @@ int64_t data_max_hm_pixel_pow(void) {
     return (int64_t)floor(log2((double)(MVEC_SIZE - g_hm_left) / (double)g_hm_pixel_count));
 }
 
+void data_update_stride(void) {
+    if (g_plot_maximized) {
+        g_plot_stride = 1;
+        g_downsampled_trace_len = g_trace_len;
+        return;
+    }
+
+    int win_height = 0;
+    glfwGetWindowSize(g_window, nullptr, &win_height);
+
+    int max_stride = g_plot_cols * ((win_height / (int)g_plot_height) + 1);
+    int max_points = DEFVAL_ENTRIES / max_stride;
+    g_plot_stride = 1;
+
+    while (g_trace_len / g_plot_stride > max_points) {
+        g_plot_stride++;
+    }
+
+    g_downsampled_trace_len = g_trace_len / g_plot_stride;
+
+    log_info("Updated plot stride: %d", g_plot_stride);
+    log_info("Updated downsampled trace-len: %d", g_downsampled_trace_len);
+}
+
 void data_on_field_change(void) {
     g_entries = std::clamp(g_entries, 1l, DEFVAL_ENTRIES);
     g_nth = std::clamp(g_nth, DEFVAL_NTH, INT64_MAX);
@@ -814,6 +842,8 @@ void data_on_field_change(void) {
 
     g_trace_len = 0l;
     g_trace_offset = 0;;
+    g_plot_stride = 0;
+    g_downsampled_trace_len = 0;
 
     for (auto &trace : g_traces) trace->clear();
     for (auto &plot: g_plots) plot->flag_for_reset();
@@ -920,6 +950,7 @@ void data_fetch(void) {
     int64_t current_size = g_traces[0]->size();
     g_trace_len = std::min(current_size, g_entries);
     g_trace_offset = current_size > g_entries ? current_size - g_entries : 0l;
+    data_update_stride();
 
     mtx_unlock(&g_fetching_mutex);
     g_status = STATUS_RUNNING;
@@ -1291,6 +1322,7 @@ void app_key_callback_plot_maximized(int key, int mods) {
         switch (key) {
         case GLFW_KEY_F:
             g_plot_maximized = false;
+            data_update_stride();
             break;
         case GLFW_KEY_SPACE:
             app_toggle_state();
@@ -1334,18 +1366,22 @@ void app_key_callback(GLFWwindow* window, int key, int scancode, int action, int
         case GLFW_KEY_LEFT:
             g_plot_cols = std::max(g_plot_cols - 1, PLOT_MIN_COLS);
             data_reset_plot_cells();
+            data_update_stride();
             break;
         case GLFW_KEY_RIGHT:
             g_plot_cols = std::min(g_plot_cols + 1, PLOT_MAX_COLS);
             data_reset_plot_cells();
+            data_update_stride();
             break;
         case GLFW_KEY_UP:
             g_plot_height = std::min(g_plot_height + PLOT_HEIGHT_INTERVAL, PLOT_MAX_HEIGHT);
             gui_plot_queue_scroll_to_position(true);
+            data_update_stride();
             break;
         case GLFW_KEY_DOWN:
             g_plot_height = std::max(g_plot_height - PLOT_HEIGHT_INTERVAL, PLOT_MIN_HEIGHT);
             gui_plot_queue_scroll_to_position(false);
+            data_update_stride();
             break;
         }
 
@@ -1372,7 +1408,11 @@ void app_key_callback(GLFWwindow* window, int key, int scancode, int action, int
             gui_plot_queue_scroll_to_selected();
             break;
         case GLFW_KEY_F:
-            if (g_plot_selected->m_visible) g_plot_maximized = !g_plot_maximized;
+            if (g_plot_selected->m_visible) {
+                g_plot_maximized = !g_plot_maximized;
+                data_update_stride();
+            }
+
             break;
         case GLFW_KEY_SPACE:
             app_toggle_state();
@@ -1387,6 +1427,14 @@ void app_key_callback(GLFWwindow* window, int key, int scancode, int action, int
     }
 }
 
+void app_window_size_callback(GLFWwindow* window, int width, int height) {
+    (void)window;
+    (void)width;
+    (void)height;
+
+    data_update_stride();
+}
+
 void app_mouse_button_callback(GLFWwindow* window, int button, int action, int mods) {
     (void)window;
     (void)mods;
@@ -1416,6 +1464,7 @@ void init() {
     assert(g_window);
     glfwSetKeyCallback(g_window, app_key_callback);
     glfwSetMouseButtonCallback(g_window, app_mouse_button_callback);
+    glfwSetWindowSizeCallback(g_window, app_window_size_callback);
     glfwMakeContextCurrent(g_window);
 #if defined(VSYNC)
     glfwSwapInterval(1);
@@ -1466,6 +1515,7 @@ void init() {
     g_plot_selected = g_plots[0];
 
     g_hm_pixel_pow = data_max_hm_pixel_pow();
+    data_update_stride();
 
     mtx_init(&g_fetching_mutex, mtx_plain);
 }
diff --git a/core/server.c b/core/server.c
index 6b81178..82b6da5 100644
--- a/core/server.c
+++ b/core/server.c
@@ -162,7 +162,7 @@ void sql_callback_add_data(sqlite3_stmt *sql_stmt, void *data) {
     }
 
     callback_context->response_rows++;
-    log_info("Added row #%ld to callback context", callback_context->response_rows);
+    log_info("Processed row #%ld", callback_context->response_rows);
     free(render_contexts);
     free(threads);
 }