From ea7520734c0038165c1526c451eca20884f95928 Mon Sep 17 00:00:00 2001
From: "Charles J. Cliffe" <cj@cubicproductions.com>
Date: Thu, 22 Oct 2015 18:21:47 -0400
Subject: [PATCH] Waterfall init re-ordering for gl context sanity

---
 src/panel/WaterfallPanel.cpp | 86 +++++++++++++++++++++---------------
 src/panel/WaterfallPanel.h   |  3 +-
 2 files changed, 53 insertions(+), 36 deletions(-)

diff --git a/src/panel/WaterfallPanel.cpp b/src/panel/WaterfallPanel.cpp
index 4720b4f..0fd2573 100644
--- a/src/panel/WaterfallPanel.cpp
+++ b/src/panel/WaterfallPanel.cpp
@@ -10,6 +10,7 @@ WaterfallPanel::WaterfallPanel() : GLPanel(), fft_size(0), waterfall_lines(0), w
 void WaterfallPanel::setup(int fft_size_in, int num_waterfall_lines_in) {
     waterfall_lines = num_waterfall_lines_in;
     fft_size = fft_size_in;
+    lines_buffered.store(0);
     
     if (points.size() != fft_size) {
         points.resize(fft_size);
@@ -23,6 +24,8 @@ void WaterfallPanel::setup(int fft_size_in, int num_waterfall_lines_in) {
         
         waterfall_ofs[i] = waterfall_lines - 1;
     }
+    texInitialized.store(false);
+    bufferInitialized.store(false);
 }
 
 void WaterfallPanel::refreshTheme() {
@@ -52,7 +55,47 @@ void WaterfallPanel::setPoints(std::vector<float> &points) {
 void WaterfallPanel::step() {
     int half_fft_size = fft_size / 2;
 
-    if (!waterfall[0]) {
+    if (!bufferInitialized.load()) {
+        if (waterfall_slice != NULL) {
+            delete waterfall_slice;
+        }
+        waterfall_slice = new unsigned char[half_fft_size];
+        bufferInitialized.store(true);
+    }
+    
+    if (!texInitialized.load()) {
+        return;
+    }
+    
+    if (points.size()) {
+        for (int j = 0; j < 2; j++) {
+            for (int i = 0, iMax = half_fft_size; i < iMax; i++) {
+                float v = points[j * half_fft_size + i];
+                
+                float wv = v < 0 ? 0 : (v > 0.99 ? 0.99 : v);
+                
+                waterfall_slice[i] = (unsigned char) floor(wv * 255.0);
+            }
+            
+            int newBufSize = (half_fft_size*lines_buffered.load()+half_fft_size);
+            if (lineBuffer[j].size() < newBufSize) {
+                lineBuffer[j].resize(newBufSize);
+                rLineBuffer[j].resize(newBufSize);
+            }
+            memcpy(&(lineBuffer[j][half_fft_size*lines_buffered.load()]), waterfall_slice, sizeof(unsigned char) * half_fft_size);
+        }
+        lines_buffered++;
+    }
+}
+
+void WaterfallPanel::update() {
+    int half_fft_size = fft_size / 2;
+    
+    if (!bufferInitialized.load()) {
+        return;
+    }
+    
+    if (!texInitialized.load()) {
         glGenTextures(2, waterfall);
         
         unsigned char *waterfall_tex;
@@ -73,48 +116,21 @@ void WaterfallPanel::step() {
             glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, half_fft_size, waterfall_lines, 0, GL_COLOR_INDEX, GL_UNSIGNED_BYTE, (GLvoid *) waterfall_tex);
         }
         
-        if (waterfall_slice != NULL) {
-            delete waterfall_slice;
-        }
-        waterfall_slice = new unsigned char[half_fft_size];
-        
         delete[] waterfall_tex;
+        
+        texInitialized.store(true);
     }
     
-    if (points.size()) {
-        for (int j = 0; j < 2; j++) {
-            for (int i = 0, iMax = half_fft_size; i < iMax; i++) {
-                float v = points[j * half_fft_size + i];
-                
-                float wv = v < 0 ? 0 : (v > 0.99 ? 0.99 : v);
-                
-                waterfall_slice[i] = (unsigned char) floor(wv * 255.0);
-            }
-            
-            int newBufSize = (half_fft_size*lines_buffered+half_fft_size);
-            if (lineBuffer[j].size() < newBufSize) {
-                lineBuffer[j].resize(newBufSize);
-                rLineBuffer[j].resize(newBufSize);
-            }
-            memcpy(&(lineBuffer[j][half_fft_size*lines_buffered]), waterfall_slice, sizeof(unsigned char) * half_fft_size);
-        }
-        lines_buffered++;
-    }
-}
-
-void WaterfallPanel::update() {
-    int half_fft_size = fft_size / 2;
-
-    for (int i = 0; i < lines_buffered; i++) {
+    for (int i = 0, iMax = lines_buffered.load(); i < iMax; i++) {
         for (int j = 0; j < 2; j++) {
             memcpy(&(rLineBuffer[j][i*half_fft_size]),
-                   &(lineBuffer[j][((lines_buffered-1)*half_fft_size)-(i*half_fft_size)]), sizeof(unsigned char) * half_fft_size);
+                   &(lineBuffer[j][((iMax-1)*half_fft_size)-(i*half_fft_size)]), sizeof(unsigned char) * half_fft_size);
         }
     }
     
     int run_ofs = 0;
-    while (lines_buffered) {
-        int run_lines = lines_buffered;
+    while (lines_buffered.load()) {
+        int run_lines = lines_buffered.load();
         if (run_lines > waterfall_ofs[0]) {
             run_lines = waterfall_ofs[0];
         }
@@ -130,7 +146,7 @@ void WaterfallPanel::update() {
             }
         }
         run_ofs += run_lines*half_fft_size;
-        lines_buffered-=run_lines;
+        lines_buffered.store(lines_buffered.load()-run_lines);
     }
 }
 
diff --git a/src/panel/WaterfallPanel.h b/src/panel/WaterfallPanel.h
index faa566a..100960f 100644
--- a/src/panel/WaterfallPanel.h
+++ b/src/panel/WaterfallPanel.h
@@ -24,7 +24,8 @@ private:
     unsigned char *waterfall_slice;
     std::vector<unsigned char> lineBuffer[2];
     std::vector<unsigned char> rLineBuffer[2];
-    int lines_buffered;
+    std::atomic_int lines_buffered;
+    std::atomic_bool texInitialized, bufferInitialized;
     
     ColorTheme *activeTheme;
 };