graphics: add support for "single buffering"
When we don't have enough video memory for double buffering we
fallback to "single buffering".
Change-Id: I8bfab6d8cd6b54f0cc6c67edc41a4c37d8fbd4ba
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
diff --git a/minui/graphics.c b/minui/graphics.c
index de1cfdf..296e2e0 100644
--- a/minui/graphics.c
+++ b/minui/graphics.c
@@ -57,6 +57,7 @@
static GGLSurface gr_framebuffer[2];
static GGLSurface gr_mem_surface;
static unsigned gr_active_fb = 0;
+static unsigned double_buffering = 0;
static int gr_fb_fd = -1;
static int gr_vt_fd = -1;
@@ -139,6 +140,12 @@
fb++;
+ /* check if we can use double buffering */
+ if (vi.yres * fi.line_length * 2 > fi.smem_len)
+ return fd;
+
+ double_buffering = 1;
+
fb->version = sizeof(*fb);
fb->width = vi.xres;
fb->height = vi.yres;
@@ -161,7 +168,7 @@
static void set_active_framebuffer(unsigned n)
{
- if (n > 1) return;
+ if (n > 1 || !double_buffering) return;
vi.yres_virtual = vi.yres * PIXEL_SIZE;
vi.yoffset = n * vi.yres;
vi.bits_per_pixel = PIXEL_SIZE * 8;
@@ -175,7 +182,8 @@
GGLContext *gl = gr_context;
/* swap front and back buffers */
- gr_active_fb = (gr_active_fb + 1) & 1;
+ if (double_buffering)
+ gr_active_fb = (gr_active_fb + 1) & 1;
/* copy data from the in-memory surface to the buffer we're about
* to make active. */
