Move waterfall animation to GPU

- Refactored texture generation to linear wrap in GPU memory with
glTexSubImage2D (1 line per frame upload max)
- Texture upload per frame reduced nearly 700-800x (~2-4kb instead of
~1.6mb)

src/visual/WaterfallContext.cpp

@@ -6,7 +6,6 @@ WaterfallContext::WaterfallContext(WaterfallCanvas *canvas, wxGLContext *sharedC
         PrimaryGLContext(canvas, sharedContext), waterfall_lines(0), fft_size(0), activeTheme(NULL) {
     for (int i = 0; i < 2; i++) {
         waterfall[i] = 0;
-        waterfall_tex[i] = 0;
     }
 }
 
@@ -21,20 +20,14 @@ void WaterfallContext::Setup(int fft_size_in, int num_waterfall_lines_in) {
             glDeleteTextures(1, &waterfall[i]);
             waterfall[i] = 0;
         }
-        if (waterfall_tex[i]) {
-            delete waterfall_tex[i];
-        }
 
-        waterfall_tex[i] = new unsigned char[half_fft_size * waterfall_lines * 2];
+        waterfall_ofs[i] = waterfall_lines - 1;
-        memset(waterfall_tex[i], 0, half_fft_size * waterfall_lines * 2);
     }
     // Stagger memory updates at half intervals for tiles
-    waterfall_ofs[0] = waterfall_lines;
-    waterfall_ofs[1] = waterfall_lines - waterfall_lines / 8;
 }
 
 void WaterfallContext::refreshTheme() {
-    glEnable(GL_TEXTURE_2D);
+    glEnable (GL_TEXTURE_2D);
 
     for (int i = 0; i < 2; i++) {
         glBindTexture(GL_TEXTURE_2D, waterfall[i]);
@@ -48,21 +41,33 @@ void WaterfallContext::refreshTheme() {
 
 void WaterfallContext::Draw(std::vector<float> &points) {
 
-    glEnable(GL_TEXTURE_2D);
+    int half_fft_size = fft_size / 2;
+
+    glEnable (GL_TEXTURE_2D);
     glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
 
     if (!waterfall[0]) {
         glGenTextures(2, waterfall);
 
+        unsigned char *waterfall_tex;
+
+        waterfall_tex = new unsigned char[half_fft_size * waterfall_lines];
+        memset(waterfall_tex, 0, half_fft_size * waterfall_lines);
+
         for (int i = 0; i < 2; i++) {
             glBindTexture(GL_TEXTURE_2D, waterfall[i]);
             glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 
             glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
-            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
+            glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
             glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
             glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+
+            glBindTexture(GL_TEXTURE_2D, waterfall[i]);
+            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, half_fft_size, waterfall_lines, 0, GL_COLOR_INDEX, GL_UNSIGNED_BYTE, (GLvoid *) waterfall_tex);
         }
+
+        delete waterfall_tex;
     }
 
     if (activeTheme != ThemeMgr::mgr.currentTheme) {
@@ -70,37 +75,24 @@ void WaterfallContext::Draw(std::vector<float> &points) {
         activeTheme = ThemeMgr::mgr.currentTheme;
     }
 
-    int half_fft_size = fft_size / 2;
-
     if (points.size()) {
+        unsigned char waterfall_slice[2][half_fft_size];
         for (int j = 0; j < 2; j++) {
-
-            int ofs = waterfall_ofs[j];
             for (int i = 0, iMax = half_fft_size; i < iMax; i++) {
                 float v = points[(j * half_fft_size + i) * 2 + 1];
 
                 float wv = v < 0 ? 0 : (v > 0.99 ? 0.99 : v);
 
-                waterfall_tex[j][i + ofs * half_fft_size] = (unsigned char) floor(wv * 255.0);
+                waterfall_slice[j][i] = (unsigned char) floor(wv * 255.0);
             }
 
-            int quarter_lines = (waterfall_lines / 4);
+            glBindTexture(GL_TEXTURE_2D, waterfall[j]);
-            int k = 4;
+            glTexSubImage2D(GL_TEXTURE_2D, 0, 0, waterfall_ofs[j], half_fft_size, 1, GL_COLOR_INDEX, GL_UNSIGNED_BYTE, (GLvoid *) waterfall_slice[j]);
-            while (k--) {
-                if (waterfall_ofs[j] == quarter_lines * k) {
-                    memcpy(waterfall_tex[j] + (waterfall_lines * half_fft_size) + (quarter_lines * k * half_fft_size),
-                            waterfall_tex[j] + (quarter_lines * k * half_fft_size), quarter_lines * half_fft_size);
-                }
-            }
 
             if (waterfall_ofs[j] == 0) {
                 waterfall_ofs[j] = waterfall_lines;
             }
 
-            glBindTexture(GL_TEXTURE_2D, waterfall[j]);
-            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, half_fft_size, waterfall_lines, 0, GL_COLOR_INDEX, GL_UNSIGNED_BYTE,
-                    (GLvoid *) (waterfall_tex[j] + (half_fft_size * (waterfall_ofs[j]))));
-
             waterfall_ofs[j]--;
         }
     }
@@ -108,35 +100,39 @@ void WaterfallContext::Draw(std::vector<float> &points) {
     glColor3f(1.0, 1.0, 1.0);
 
     GLint vp[4];
-    glGetIntegerv( GL_VIEWPORT, vp);
+    glGetIntegerv(GL_VIEWPORT, vp);
 
     float viewWidth = (float) vp[2];
+    float viewHeight = (float) vp[3];
 
     // some bias to prevent seams at odd scales
-    float half_pixel = 1.0 / (float) viewWidth;
+    float half_pixel = 1.0 / viewWidth;
     float half_texel = 1.0 / (float) half_fft_size;
+    float vtexel = 1.0 / (float) waterfall_lines;
+    float vofs = (float) (waterfall_ofs[0] + 1) * vtexel;
 
     glBindTexture(GL_TEXTURE_2D, waterfall[0]);
-    glBegin(GL_QUADS);
+    glBegin (GL_QUADS);
-    glTexCoord2f(0.0 + half_texel, 1.0 - half_texel);
+    glTexCoord2f(0.0 + half_texel, 1.0 + vofs);
     glVertex3f(-1.0, -1.0, 0.0);
-    glTexCoord2f(1.0 - half_texel, 1.0 - half_texel);
+    glTexCoord2f(1.0 - half_texel, 1.0 + vofs);
     glVertex3f(0.0 + half_pixel, -1.0, 0.0);
-    glTexCoord2f(1.0 - half_texel, 0.0 + half_texel);
+    glTexCoord2f(1.0 - half_texel, 0.0 + vofs);
     glVertex3f(0.0 + half_pixel, 1.0, 0.0);
-    glTexCoord2f(0.0 + half_texel, 0.0 + half_texel);
+    glTexCoord2f(0.0 + half_texel, 0.0 + vofs);
     glVertex3f(-1.0, 1.0, 0.0);
     glEnd();
 
+    vofs = (float) (waterfall_ofs[1] + 1) * vtexel;
     glBindTexture(GL_TEXTURE_2D, waterfall[1]);
     glBegin(GL_QUADS);
-    glTexCoord2f(0.0 + half_texel, 1.0 - half_texel);
+    glTexCoord2f(0.0 + half_texel, 1.0 + vofs);
     glVertex3f(0.0 - half_pixel, -1.0, 0.0);
-    glTexCoord2f(1.0 - half_texel, 1.0 - half_texel);
+    glTexCoord2f(1.0 - half_texel, 1.0 + vofs);
     glVertex3f(1.0, -1.0, 0.0);
-    glTexCoord2f(1.0 - half_texel, 0.0 + half_texel);
+    glTexCoord2f(1.0 - half_texel, 0.0 + vofs);
     glVertex3f(1.0, 1.0, 0.0);
-    glTexCoord2f(0.0 + half_texel, 0.0 + half_texel);
+    glTexCoord2f(0.0 + half_texel, 0.0 + vofs);
     glVertex3f(0.0 - half_pixel, 1.0, 0.0);
     glEnd();
 
@@ -144,5 +140,4 @@ void WaterfallContext::Draw(std::vector<float> &points) {
 
     glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
     glDisable(GL_TEXTURE_2D);
-
 }

src/visual/WaterfallContext.h

@@ -16,7 +16,6 @@ public:
 
 private:
     GLuint waterfall[2];
-    unsigned char *waterfall_tex[2];
     int waterfall_ofs[2];
     int fft_size;
     int waterfall_lines;