Changeset 683 for soft/giet_vm/applications/raycast/disp.c

Timestamp:

Aug 3, 2015, 7:07:02 PM (9 years ago)

Author:

guerin

Message:

raycast: initial distributed implementation

The main task runs on processor (0,0,0). It manages game logic and
initialization, and participates in the rendering process.
The render task runs on all other processors. It tries to render a frame
slice when available, which is raycasting + pixel drawing for a pixel
column of the frame.

File:

• soft/giet_vm/applications/raycast/disp.c (modified) (6 diffs)

soft/giet_vm/applications/raycast/disp.c

@@ -6 +6 @@
 #include <math.h>
 #include <hard_config.h>
+#include <user_sqt_lock.h>
 
 #define FIELD_OF_VIEW   (70.f * M_PI / 180.f)   // Camera field of view
@@ -14 +15 @@
 // Globals
 
-static unsigned char* buf[2];
-static void *         sts[2];
-static unsigned int   cur_buf;
+static unsigned char*           buf[2];         // framebuffer
+static void *                   sts[2];         // for fbf_cma
+static unsigned int             cur_buf;        // current framebuffer
+static volatile unsigned int    slice_x;        // slice index (shared)
+static sqt_lock_t               slice_x_lock;   // slice index lock
+static volatile unsigned int    slice_cnt;      // slice count (shared)
 
 // Textures indexed by block number
@@ -168 +172 @@
 }
 
-static unsigned char *loadTexture(char *path)
+static unsigned char *dispLoadTexture(char *path)
 {
     int fd;
@@ -191 +195 @@
 void dispInit()
 {
-    // allocate framebuffer
+    unsigned int w, h, p;
+
+    // Initialize lock
+    giet_procs_number(&w, &h, &p);
+    sqt_lock_init(&slice_x_lock, w, h, p);
+
+    // Allocate framebuffer
     buf[0] = almalloc(64, FBUF_X_SIZE * FBUF_Y_SIZE);
     buf[1] = almalloc(64, FBUF_X_SIZE * FBUF_Y_SIZE);
@@ -197 +207 @@
     sts[1] = almalloc(64, 64);
 
-    // initialize framebuffer
+    // Initialize framebuffer
     giet_fbf_cma_alloc();
     giet_fbf_cma_init_buf(buf[0], buf[1], sts[0], sts[1]);
     giet_fbf_cma_start(FBUF_X_SIZE * FBUF_Y_SIZE);
 
-    // load textures
-    g_tex[1] = loadTexture("misc/rock_32.raw");
-    g_tex[2] = loadTexture("misc/door_32.raw");
-    g_tex[3] = loadTexture("misc/handle_32.raw");
-    g_tex[4] = loadTexture("misc/wood_32.raw");
+    // Load textures
+    g_tex[1] = dispLoadTexture("misc/rock_32.raw");
+    g_tex[2] = dispLoadTexture("misc/door_32.raw");
+    g_tex[3] = dispLoadTexture("misc/handle_32.raw");
+    g_tex[4] = dispLoadTexture("misc/wood_32.raw");
 
     cur_buf = 0;
+    slice_cnt = 0;
+    slice_x = FBUF_X_SIZE;
+}
+
+int dispRenderSlice(Game *game)
+{
+    unsigned int x;
+    int type;
+    float angle, dist, tx;
+
+    sqt_lock_acquire(&slice_x_lock);
+
+    if (slice_x == FBUF_X_SIZE) {
+        // No more work to do for this frame
+        sqt_lock_release(&slice_x_lock);
+        return 0;
+    }
+    else {
+        // Keep slice coordinate
+        x = slice_x++;
+    }
+
+    sqt_lock_release(&slice_x_lock);
+
+    angle = game->player.dir - FIELD_OF_VIEW / 2.f +
+            x * FIELD_OF_VIEW / FBUF_X_SIZE;
+
+    // Cast a ray to get wall distance
+    dist = dispRaycast(game, &type, &tx, angle);
+
+    // Perspective correction
+    dist *= cos(game->player.dir - angle);
+
+    // Draw ceiling, wall and floor
+    dispDrawSlice(game, x, FBUF_Y_SIZE / dist, type, tx);
+
+    // Signal this slice is done
+    atomic_increment((unsigned int*)&slice_cnt, 1);
+
+    return 1;
 }
 
@@ -214 +264 @@
 {
     int start = giet_proctime();
-    float angle = game->player.dir - FIELD_OF_VIEW / 2.f;
-
-    // Cast a ray for each pixel column and draw a colored wall slice
-    for (int i = 0; i < FBUF_X_SIZE; i++)
-    {
-        float dist;
-        int type;
-        float tx;
-
-        // Cast a ray to get wall distance
-        dist = dispRaycast(game, &type, &tx, angle);
-
-        // Perspective correction
-        dist *= cos(game->player.dir - angle);
-
-        // Draw ceiling, wall and floor
-        dispDrawSlice(game, i, FBUF_Y_SIZE / dist, type, tx);
-
-        angle += FIELD_OF_VIEW / FBUF_X_SIZE;
-    }
-
+
+    // Start rendering
+    slice_cnt = 0;
+    slice_x = 0;
+
+    // Render slices
+    while (dispRenderSlice(game));
+
+    // Wait for completion
+    while (slice_cnt != FBUF_X_SIZE);
+
+    // Flip framebuffer
     giet_fbf_cma_display(cur_buf);
     cur_buf = !cur_buf;
     giet_tty_printf("[RAYCAST] flip (took %d cycles)\n", giet_proctime() - start);
 }
+