Split SDL heatmap streaming

Author: cirosantilli

bullet/README.md

@@ -9,6 +9,7 @@ Tested on Bullet 2.83, Ubuntu 16.04.
     1.  [Build](build.md)
     1.  [Source code](source-code.md)
     1.  [Users](users.md)
+    1.  [Benchmarks](benchmarks.md)
 1.  Examples
     1.  [Gravity](gravity.cpp)
     1.  [Gravity collision](gravity_collision.cpp)

bullet/benchmarks.md

@@ -0,0 +1,3 @@
+# Benchmarks
+
+<https://grasp.robotics.cs.rpi.edu/bpmd/>

sdl/README.md

@@ -15,6 +15,7 @@
     1.  Plots
         1.  [heatmap 1D](heatmap1d.c)
         1.  [heatmap](heatmap.c)
+        1.  [heatmap streaming](heatmap_streaming.c)
         1.  [heatmap shader](heatmap_shader.c)
     1.  [OpenGL](opengl.c)
     1.  Audio

sdl/heatmap.c

@@ -29,26 +29,26 @@ TODO: why do I see some tearing. vsync problem?
 
 #include "common.h"
 
-/* Input parameters. Play with those to try to increase FPS. */
+/*
+Turn SDL on or off.
+If off, no window is created, but computations are still run.
+Play with those to try to increase FPS and find out if the limiting factor is computation or display.
+*/
 #define SDL 1
-#define STREAMING (SDL && 1)
 
 #define COLOR_MAX 255
 
 int main(void) {
 #if SDL
     SDL_Event event;
-    SDL_Rect rect;
     SDL_Renderer *renderer;
     SDL_Window *window;
-# if STREAMING
     SDL_Texture *texture = NULL;
     void *pixels;
     Uint8 *base;
     /* TODO: is it mandatory to use this? Maybe SDL_LockTexture
      * will make the array non continuous to improve alignment? */
     int pitch;
-# endif
 #else
     double sum;
 #endif
@@ -68,47 +68,27 @@ int main(void) {
 #if SDL
     SDL_Init(SDL_INIT_TIMER | SDL_INIT_VIDEO);
     SDL_CreateWindowAndRenderer(WINDOW_WIDTH, WINDOW_WIDTH, 0, &window, &renderer);
-# if STREAMING
-    texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_ARGB8888,
-        SDL_TEXTUREACCESS_STREAMING, WINDOW_WIDTH, WINDOW_HEIGHT);
-# endif
 #endif
     initial_time = common_get_secs();
     common_fps_init();
     while (1) {
         dt = common_get_secs() - initial_time;
-#if STREAMING
-        SDL_LockTexture(texture, NULL, &pixels, &pitch);
-#endif
         for (x = 0; x < WINDOW_WIDTH; x++) {
             for (y = 0; y < WINDOW_HEIGHT; y++) {
                 xc = CENTER_X - x;
                 yc = CENTER_Y - y;
                 z = COLOR_MAX * 0.5 * (1.0 + (sin(PI2 * (sqrt(xc*xc + yc*yc) - SPEED * dt) / PERIOD)));
+                /*z = (int)(x + y + SPEED * dt) % COLOR_MAX;*/
 #if SDL
-# if STREAMING
-                base = ((Uint8 *)pixels) + (4 * (x * WINDOW_WIDTH + y));
-                base[0] = 0;
-                base[1] = 0;
-                base[2] = z;
-                base[3] = COLOR_MAX;
-# else
                 SDL_SetRenderDrawColor(renderer, z, 0, 0, COLOR_MAX);
                 SDL_RenderDrawPoint(renderer, x, y);
-# endif
 #else
                 sum += z;
 #endif
             }
         }
 #if SDL
-# if STREAMING
-        SDL_UnlockTexture(texture);
-        SDL_RenderCopy(renderer, texture, NULL, NULL);
-# endif
         SDL_RenderPresent(renderer);
-#endif
-#if SDL
         common_fps_update_and_print();
         if (SDL_PollEvent(&event) && event.type == SDL_QUIT)
             break;

sdl/heatmap_streaming.c

@@ -0,0 +1,59 @@
+#include "common.h"
+
+#define COLOR_MAX 255
+
+int main(void) {
+    SDL_Event event;
+    SDL_Renderer *renderer = NULL;
+    SDL_Texture *texture = NULL;
+    SDL_Window *window = NULL;
+    Uint8 *base;
+    int pitch;
+    void *pixels = NULL;
+    const unsigned int
+        WINDOW_WIDTH = 500,
+        WINDOW_HEIGHT = WINDOW_WIDTH;
+    const double
+        SPEED = WINDOW_WIDTH / 10.0,
+        CENTER_X = WINDOW_WIDTH / 2.0,
+        CENTER_Y = WINDOW_HEIGHT / 2.0,
+        PERIOD = WINDOW_WIDTH / 10.0,
+        PI2 = 2.0 * acos(-1.0);
+    double dt, initial_time;
+    float z;
+    unsigned int x, xc, y, yc;
+
+    SDL_Init(SDL_INIT_TIMER | SDL_INIT_VIDEO);
+    SDL_CreateWindowAndRenderer(WINDOW_WIDTH, WINDOW_WIDTH, 0, &window, &renderer);
+    texture = SDL_CreateTexture(renderer, SDL_PIXELFORMAT_ARGB8888,
+        SDL_TEXTUREACCESS_STREAMING, WINDOW_WIDTH, WINDOW_HEIGHT);
+    initial_time = common_get_secs();
+    common_fps_init();
+    while (1) {
+        dt = common_get_secs() - initial_time;
+        SDL_LockTexture(texture, NULL, &pixels, &pitch);
+        for (x = 0; x < WINDOW_WIDTH; x++) {
+            for (y = 0; y < WINDOW_HEIGHT; y++) {
+                xc = CENTER_X - x;
+                yc = CENTER_Y - y;
+                z = COLOR_MAX * 0.5 * (1.0 + (sin(PI2 * (sqrt(xc*xc + yc*yc) - SPEED * dt) / PERIOD)));
+                /*z = (int)(x + y + SPEED * dt) % COLOR_MAX;*/
+                base = ((Uint8 *)pixels) + (4 * (x * WINDOW_WIDTH + y));
+                base[0] = 0;
+                base[1] = 0;
+                base[2] = z;
+                base[3] = COLOR_MAX;
+            }
+        }
+        SDL_UnlockTexture(texture);
+        SDL_RenderCopy(renderer, texture, NULL, NULL);
+        SDL_RenderPresent(renderer);
+        common_fps_update_and_print();
+        if (SDL_PollEvent(&event) && event.type == SDL_QUIT)
+            break;
+    }
+    SDL_DestroyRenderer(renderer);
+    SDL_DestroyWindow(window);
+    SDL_Quit();
+    return EXIT_SUCCESS;
+}