Dynamic resolution

1 files changed, 125 insertions, 31 deletions

diff --git a/reduced_system_layer.c b/reduced_system_layer.c
index af49453..9eabca9 100755
--- a/reduced_system_layer.c
+++ b/reduced_system_layer.c
@@ -44,6 +44,7 @@
 #/  - Networking
 #/    - Windows sockets
 #/  - Graphics
+#/    - Relative coordinates
 #/    - Self-contained impl
 #/    - UI
 #/    - Icons
@@ -73,6 +74,7 @@
 #/  - Testing
 #/  - Graphics
 #/    - Font
+#/    - Adaptive resolution
 #/
 #/  ----------------------------------------------------------------
 #/
@@ -169,11 +171,15 @@ extern "C" {
 #endif
 
 enum {
-  MAX_NUM_PIXELS       = 10 * 1024 * 1024,
-  MAX_INPUT_SIZE       = 256,
-  MAX_CLIPBOARD_SIZE   = 10 * 1024 * 1024,
-  MAX_NUM_SOCKETS      = 64,
-  MAX_NUM_KEYS         = 512,
+  MAX_NUM_PIXELS     = 10 * 1024 * 1024,
+  MAX_INPUT_SIZE     = 256,
+  MAX_CLIPBOARD_SIZE = 10 * 1024 * 1024,
+  MAX_NUM_SOCKETS    = 64,
+  MAX_NUM_KEYS       = 512,
+  MAX_PIXEL_SIZE     = 16,
+
+  MIN_FRAME_DURATION = 9,
+  MAX_FRAME_DURATION = 38,
 
   AUDIO_NUM_CHANNELS = 2,
   AUDIO_SAMPLE_RATE  = 44100,
@@ -331,6 +337,7 @@ typedef struct {
   i64        clipboard_size;
   c8  *      clipboard;
   b8         done;
+  b8         exact_resolution; // TODO
   b8         graceful_exit;
   b8         has_focus;
   b8         has_cursor;
@@ -488,8 +495,6 @@ i32 main(i32 argc, c8 **argv) {
 Platform g_platform = {0};
 
 void p_event_loop(void) {
-  (void) sqrt; // For the compiler.
-
   p_init();
 #if !defined(__wasm__)
   while (!g_platform.done) update_and_render_frame();
@@ -1064,7 +1069,10 @@ void p_queue_sound(i64 delay_in_samples, i64 num_samples, f32 *frames) {
 
 static i16       _key_table[MAX_NUM_KEYS]              = {0};
 static b8        _key_repeat[MAX_NUM_KEYS]             = {0};
+static i64       _frame_time                           = 0;
 static vec3_f32  _pixels[MAX_NUM_PIXELS]               = {0};
+static i32       _pixel_size                           = 0;
+static u32       _pixels_scaled[MAX_NUM_PIXELS]        = {0};
 static u32       _pixels_internal[MAX_NUM_PIXELS]      = {0};
 static Input_Key _input[MAX_INPUT_SIZE]                = {0};
 static c8        _clipboard_buffer[MAX_CLIPBOARD_SIZE] = {0};
@@ -1246,7 +1254,7 @@ void p_init(void) {
     .bitmap_bit_order = LSBFirst,
     .bitmap_pad       = 32,
     .bits_per_pixel   = 32,
-    .bytes_per_line   = 4 * g_platform.frame_width,
+    .bytes_per_line   = _image.width * 4,
     .red_mask         = 0xff0000,
     .green_mask       = 0x00ff00,
     .blue_mask        = 0x0000ff,
@@ -1267,7 +1275,7 @@ void p_init(void) {
 
   XMapWindow(_display, _window);
 
-  XPutImage(_display, _window, _gc, &_image, 0, 0, 0, 0, g_platform.frame_width, g_platform.frame_height);
+  XPutImage(_display, _window, _gc, &_image, 0, 0, 0, 0, _image.width, _image.height);
   XFlush(_display);
 }
 
@@ -1291,6 +1299,8 @@ i32 p_handle_events(void) {
   if (_display == NULL)
     return 0;
 
+  _frame_time = p_time();
+
   i32 num_events = 0;
 
   memset(g_platform.key_pressed, 0, sizeof g_platform.key_pressed);
@@ -1550,15 +1560,26 @@ i32 p_handle_events(void) {
   XWindowAttributes attrs;
   XGetWindowAttributes(_display, _window, &attrs);
 
-  if ((g_platform.frame_width != attrs.width || g_platform.frame_height != attrs.height) && attrs.width * attrs.height * 4 <= (i32) sizeof _pixels_internal) {
-    if (attrs.width > 0 && attrs.height > 0) {
-      _image.width          = attrs.width;
-      _image.height         = attrs.height;
-      _image.bytes_per_line = 4 * attrs.width;
+  if (attrs.width > 0 && attrs.height > 0 && attrs.width * attrs.height <= MAX_NUM_PIXELS) {
+    _image.width          = attrs.width;
+    _image.height         = attrs.height;
+    _image.bytes_per_line = _image.width * 4;
+
+    i32 width  = _image.width;
+    i32 height = _image.height;
+
+    if (_pixel_size <= 1)
+      _pixel_size = 1;
+    else {
+      width  = (i32) floor(((f64) _image.width)  / _pixel_size + .5);
+      height = (i32) floor(((f64) _image.height) / _pixel_size + .5);
     }
 
-    g_platform.frame_width  = attrs.width;
-    g_platform.frame_height = attrs.height;
+    if (g_platform.frame_width != width || g_platform.frame_height != height) {
+      ++num_events;
+      g_platform.frame_width  = width;
+      g_platform.frame_height = height;
+    }
   }
 
   return num_events;
@@ -1567,10 +1588,12 @@ i32 p_handle_events(void) {
 i32 p_wait_events(void) {
   i32 num_events = 0;
 
-  do {
+  for (;;) {
     num_events = p_handle_events();
+    if (num_events != 0)
+      break;
     usleep(0);
-  } while (num_events == 0);
+  }
 
   return num_events;
 }
@@ -1579,12 +1602,35 @@ void p_render_frame(void) {
   if (g_platform.done)
     return;
 
-  i64 size = g_platform.frame_width * g_platform.frame_height;
-  for (i64 i = 0; i < size; ++i)
-    _pixels_internal[i] = rgb_u32_from_f32(_pixels[i]);
+  if (g_platform.frame_width == _image.width && g_platform.frame_height == _image.height) {
+    i64 size = g_platform.frame_width * g_platform.frame_height;
+    for (i64 i = 0; i < size; ++i)
+      _pixels_internal[i] = rgb_u32_from_f32(_pixels[i]);
+  } else {
+    i64 size = g_platform.frame_width * g_platform.frame_height;
+    for (i64 i = 0; i < size; ++i)
+      _pixels_scaled[i] = rgb_u32_from_f32(_pixels[i]);
+
+    for (i64 j = 0; j < _image.height; ++j) {
+      i64 j0 = (j * g_platform.frame_height) / _image.height;
+      for (i64 i = 0; i < _image.width; ++i) {
+        i64 i0 = (i * g_platform.frame_width) / _image.width;
+        _pixels_internal[j * _image.width + i] = _pixels_scaled[j0 * g_platform.frame_width + i0];
+      }
+    }
+  }
 
-  XPutImage(_display, _window, _gc, &_image, 0, 0, 0, 0, g_platform.frame_width, g_platform.frame_height);
+  XPutImage(_display, _window, _gc, &_image, 0, 0, 0, 0, _image.width, _image.height);
   XFlush(_display);
+
+  if (!g_platform.exact_resolution) {
+    i64 frame_duration = p_time() - _frame_time;
+
+    if (_pixel_size < MAX_PIXEL_SIZE && frame_duration > MAX_FRAME_DURATION)
+      ++_pixel_size;
+    else if (_pixel_size > 1 && frame_duration < MIN_FRAME_DURATION)
+      --_pixel_size;
+  }
 }
 
 void p_clipboard_write(i64 size, c8 *data) {
@@ -1610,7 +1656,11 @@ void p_clipboard_write(i64 size, c8 *data) {
 
 #ifdef __wasm__
 
+static i32       _frame_width                          = 0;
+static i32       _frame_height                         = 0;
 static vec3_f32  _pixels[MAX_NUM_PIXELS]               = {0};
+static i32       _pixel_size                           = 0;
+static u32       _pixels_scaled[MAX_NUM_PIXELS]        = {0};
 static u32       _pixels_internal[MAX_NUM_PIXELS]      = {0};
 static Input_Key _input[MAX_INPUT_SIZE]                = {0};
 static c8        _clipboard_buffer[MAX_CLIPBOARD_SIZE] = {0};
@@ -1645,11 +1695,13 @@ void p_init(void) {
 
 i32 p_handle_events(void) {
   g_platform.input_size = _input_size;
-  _input_size         = 0;
+  _input_size = 0;
+
   for (i64 i = 0; i < MAX_NUM_KEYS; ++i)
     g_platform.key_pressed[i] = _key_pressed[i];
   for (i64 i = 0; i < MAX_NUM_KEYS; ++i)
     _key_pressed[i] = 0;
+
   i32 n = _num_events;
   _num_events = 0;
   return n;
@@ -1662,9 +1714,23 @@ i32 p_wait_events(void) {
 }
 
 void p_render_frame(void) {
-  i64 size = g_platform.frame_width * g_platform.frame_height;
-  for (i64 i = 0; i < size; ++i)
-    _pixels_internal[i] = 0xff000000u | rgb_u32_from_f32(_pixels[i]);
+  if (_frame_width == g_platform.frame_width && _frame_height == g_platform.frame_height) {
+    i64 size = g_platform.frame_width * g_platform.frame_height;
+    for (i64 i = 0; i < size; ++i)
+      _pixels_internal[i] = 0xff000000u | rgb_u32_from_f32(_pixels[i]);
+  } else {
+    i64 size = g_platform.frame_width * g_platform.frame_height;
+    for (i64 i = 0; i < size; ++i)
+      _pixels_scaled[i] = rgb_u32_from_f32(_pixels[i]);
+
+    for (i64 j = 0; j < _frame_height; ++j) {
+      i64 j0 = (j * g_platform.frame_height) / _frame_height;
+      for (i64 i = 0; i < _frame_width; ++i) {
+        i64 i0 = (i * g_platform.frame_width) / _frame_width;
+        _pixels_internal[j * _frame_width + i] = 0xff000000u | _pixels_scaled[j0 * g_platform.frame_width + i0];
+      }
+    }
+  }
 }
 
 void p_clipboard_write_impl(i32 size, c8 *data);
@@ -1735,15 +1801,34 @@ __attribute__((export_name("js_pixels"))) void *js_pixels(void) {
 }
 
 __attribute__((export_name("js_frame"))) void js_frame(i32 frame_width, i32 frame_height, i32 num_samples) {
-  if (g_platform.frame_width != frame_width || g_platform.frame_height != frame_height) {
-    ++_num_events;
-    g_platform.frame_width  = frame_width;
-    g_platform.frame_height = frame_height;
+  i64 frame_time = p_time();
+
+  if (frame_width > 0 && frame_height > 0 && frame_width * frame_height <= MAX_NUM_PIXELS) {
+    _frame_width  = frame_width;
+    _frame_height = frame_height;
+
+    i32 width  = _frame_width;
+    i32 height = _frame_height;
+
+    if (_pixel_size <= 1)
+      _pixel_size = 1;
+    else {
+      width  = (i32) floor(((f64) _frame_width)  / _pixel_size + .5);
+      height = (i32) floor(((f64) _frame_height) / _pixel_size + .5);
+    }
+
+    if (g_platform.frame_width != width || g_platform.frame_height != height) {
+      ++_num_events;
+      g_platform.frame_width  = width;
+      g_platform.frame_height = height;
+    }
   }
 
   g_platform.done = 0;
 
-  if (_num_events > 0 || !_wait_events) {
+  b8 do_render = _num_events > 0 || !_wait_events;
+
+  if (do_render) {
     _wait_events = 0;
     update_and_render_frame();
   }
@@ -1757,6 +1842,15 @@ __attribute__((export_name("js_frame"))) void js_frame(i32 frame_width, i32 fram
     }
 
   _sound_read = (_sound_read + num_samples * AUDIO_NUM_CHANNELS) % MAX_NUM_AUDIO_FRAMES;
+
+  if (!g_platform.exact_resolution && do_render) {
+    i64 frame_duration = p_time() - frame_time;
+
+    if (_pixel_size < MAX_PIXEL_SIZE && frame_duration > MAX_FRAME_DURATION)
+      ++_pixel_size;
+    else if (_pixel_size > 1 && frame_duration < MIN_FRAME_DURATION)
+      --_pixel_size;
+  }
 }
 
 __attribute__((export_name("js_mousemove"))) void js_mousemove(i32 x, i32 y) {