From 51cff8bdedbc283b2403ab4a688903d8b1f2fab5 Mon Sep 17 00:00:00 2001

From: David Herrmann <dh.herrmann@gmail.com>

Date: Thu, 2 Oct 2014 18:26:06 +0200

Subject: [PATCH] terminal/grdev: provide front and back buffer to renderers

We really want more sophisticated aging than just 64bit integers. So

always provide front *and* back buffers to renderers so they can compare

arbitrary aging information and decide whether to re-render.

---

 src/libsystemd-terminal/grdev.c   | 27 ++++++++++-----------------

 src/libsystemd-terminal/grdev.h   | 13 +++++++------

 src/libsystemd-terminal/modeset.c |  8 ++++----

 3 files changed, 21 insertions(+), 27 deletions(-)

diff --git a/src/libsystemd-terminal/grdev.c b/src/libsystemd-terminal/grdev.c

index bbc45afad4..a700a7316b 100644

--- a/src/libsystemd-terminal/grdev.c

+++ b/src/libsystemd-terminal/grdev.c

@@ -343,7 +343,7 @@ void grdev_display_disable(grdev_display *display) {

         }

 }

-const grdev_display_target *grdev_display_next_target(grdev_display *display, const grdev_display_target *prev, uint64_t minage) {

+const grdev_display_target *grdev_display_next_target(grdev_display *display, const grdev_display_target *prev) {

         grdev_display_cache *cache;

         size_t idx;

@@ -374,26 +374,19 @@ const grdev_display_target *grdev_display_next_target(grdev_display *display, co

                 if (!pipe->running || !pipe->enabled)

                         continue;

-                /* if front-buffer is up-to-date, there's nothing to do */

-                if (minage > 0 && pipe->front && pipe->front->age >= minage)

-                        continue;

-

                 /* find suitable back-buffer */

-                if (!(fb = pipe->back)) {

-                        if (!pipe->vtable->target || !(fb = pipe->vtable->target(pipe)))

+                if (!pipe->back) {

+                        if (!pipe->vtable->target)

+                                continue;

+                        if (!(fb = pipe->vtable->target(pipe)))

                                 continue;

                         assert(fb == pipe->back);

                 }

-                /* if back-buffer is up-to-date, schedule flip */

-                if (minage > 0 && fb->age >= minage) {

-                        grdev_display_flip_target(display, target, fb->age);

-                        continue;

-                }

+                target->front = pipe->front;

+                target->back = pipe->back;

-                /* we have an out-of-date back-buffer; return for redraw */

-                target->fb = fb;

                 return target;

         }

@@ -408,7 +401,7 @@ void grdev_display_flip_target(grdev_display *display, const grdev_display_targe

         assert(!display->modified);

         assert(display->enabled);

         assert(target);

-        assert(target->fb);

+        assert(target->back);

         cache = container_of(target, grdev_display_cache, target);

@@ -416,12 +409,12 @@ void grdev_display_flip_target(grdev_display *display, const grdev_display_targe

         assert(cache->pipe->tile->display == display);

         /* reset age of all FB on overflow */

-        if (age < target->fb->age)

+        if (age < target->back->age)

                 for (i = 0; i < cache->pipe->max_fbs; ++i)

                         if (cache->pipe->fbs[i])

                                 cache->pipe->fbs[i]->age = 0;

-        ((grdev_fb*)target->fb)->age = age;

+        ((grdev_fb*)target->back)->age = age;

         cache->pipe->flip = true;

 }

diff --git a/src/libsystemd-terminal/grdev.h b/src/libsystemd-terminal/grdev.h

index 6ca8a767c4..ca0373ed29 100644

--- a/src/libsystemd-terminal/grdev.h

+++ b/src/libsystemd-terminal/grdev.h

@@ -105,7 +105,8 @@ struct grdev_display_target {

         uint32_t height;

         unsigned int rotate;

         unsigned int flip;

-        const grdev_fb *fb;

+        const grdev_fb *front;

+        const grdev_fb *back;

 };

 void grdev_display_set_userdata(grdev_display *display, void *userdata);

@@ -119,13 +120,13 @@ bool grdev_display_is_enabled(grdev_display *display);

 void grdev_display_enable(grdev_display *display);

 void grdev_display_disable(grdev_display *display);

-const grdev_display_target *grdev_display_next_target(grdev_display *display, const grdev_display_target *prev, uint64_t minage);

+const grdev_display_target *grdev_display_next_target(grdev_display *display, const grdev_display_target *prev);

 void grdev_display_flip_target(grdev_display *display, const grdev_display_target *target, uint64_t age);

-#define GRDEV_DISPLAY_FOREACH_TARGET(_display, _t, _minage)                     \

-        for ((_t) = grdev_display_next_target((_display), NULL, (_minage));     \

-             (_t);                                                              \

-             (_t) = grdev_display_next_target((_display), (_t), (_minage)))

+#define GRDEV_DISPLAY_FOREACH_TARGET(_display, _t)                      \

+        for ((_t) = grdev_display_next_target((_display), NULL);        \

+             (_t);                                                      \

+             (_t) = grdev_display_next_target((_display), (_t)))

 /*

  * Events

diff --git a/src/libsystemd-terminal/modeset.c b/src/libsystemd-terminal/modeset.c

index f564fa0f65..2f8860dd5f 100644

--- a/src/libsystemd-terminal/modeset.c

+++ b/src/libsystemd-terminal/modeset.c

@@ -234,18 +234,18 @@ static void modeset_draw(Modeset *m, const grdev_display_target *t) {

         uint32_t j, k, *b;

         uint8_t *l;

-        assert(t->fb->format == DRM_FORMAT_XRGB8888 || t->fb->format == DRM_FORMAT_ARGB8888);

+        assert(t->back->format == DRM_FORMAT_XRGB8888 || t->back->format == DRM_FORMAT_ARGB8888);

         assert(!t->rotate);

         assert(!t->flip);

-        l = t->fb->maps[0];

+        l = t->back->maps[0];

         for (j = 0; j < t->height; ++j) {

                 for (k = 0; k < t->width; ++k) {

                         b = (uint32_t*)l;

                         b[k] = (0xff << 24) | (m->r << 16) | (m->g << 8) | m->b;

                 }

-                l += t->fb->strides[0];

+                l += t->back->strides[0];

         }

 }

@@ -256,7 +256,7 @@ static void modeset_render(Modeset *m, grdev_display *d) {

         m->g = next_color(&m->g_up, m->g, 3);

         m->b = next_color(&m->b_up, m->b, 2);

-        GRDEV_DISPLAY_FOREACH_TARGET(d, t, 0) {

+        GRDEV_DISPLAY_FOREACH_TARGET(d, t) {

                 modeset_draw(m, t);

                 grdev_display_flip_target(d, t, 1);

         }