convert LorieBuffer to shareable type if app requests window flip

Author: twaik

app/src/main/cpp/lorie/InitOutput.c

@@ -743,11 +743,48 @@ static void loriePerformVblanks(void) {
     }
 }
 
+Bool loriePresentCheckFlip(__unused RRCrtcPtr crtc, WindowPtr window, PixmapPtr pixmap, __unused Bool sync_flip) {
+    LoriePixmapPriv* priv = (LoriePixmapPriv*) exaGetPixmapDriverPrivate(pixmap);
+    if (!priv || !priv->buffer || priv->mem)
+        return FALSE;
+
+    const LorieBuffer_Desc *desc = LorieBuffer_description(priv->buffer);
+    if (desc->type == LORIEBUFFER_REGULAR) {
+        // Regular buffers can not be shared to activity, we must explicitly convert LorieBuffer to FD or AHardwareBuffer
+        int8_t type = pvfb->root.legacyDrawing ? LORIEBUFFER_FD : LORIEBUFFER_AHARDWAREBUFFER;
+        int8_t format = pvfb->root.flip ? AHARDWAREBUFFER_FORMAT_R8G8B8X8_UNORM : AHARDWAREBUFFER_FORMAT_B8G8R8A8_UNORM;
+        LorieBuffer_convert(priv->buffer, type, format);
+        if (desc->type != LORIEBUFFER_REGULAR) {
+            // LorieBuffer_convert does not report status but it does not let the type change in the case of error.
+            pScreenPtr->ModifyPixmapHeader(pixmap, 0, 0, 0, 0, desc->stride * 4, NULL);
+            LorieBuffer_lock(priv->buffer, &priv->locked);
+        }
+    }
+
+    if (desc->type != LORIEBUFFER_FD && desc->type != LORIEBUFFER_AHARDWAREBUFFER)
+        return FALSE;
+
+    /* currently not implemented */
+    return FALSE;
+}
+
+Bool loriePresentFlip(__unused RRCrtcPtr crtc, uint64_t event_id, uint64_t target_msc, PixmapPtr pixmap, __unused Bool sync_flip) {
+    /* currently not implemented */
+    return FALSE;
+}
+
+void loriePresentUnflip(__unused ScreenPtr screen, uint64_t event_id) {
+    /* currently not implemented */
+}
+
 static struct present_screen_info loriePresentInfo = {
         .get_crtc = loriePresentGetCrtc,
         .get_ust_msc = loriePresentGetUstMsc,
         .queue_vblank = loriePresentQueueVblank,
         .abort_vblank = loriePresentAbortVblank,
+        .check_flip = loriePresentCheckFlip,
+        .flip = loriePresentFlip,
+        .unflip = loriePresentUnflip,
 };
 
 void exaDDXDriverInit(__unused ScreenPtr pScreen) {}

app/src/main/cpp/lorie/buffer.c

@@ -189,6 +189,56 @@ __LIBC_HIDDEN__ LorieBuffer* LorieBuffer_wrapAHardwareBuffer(AHardwareBuffer* bu
     return allocate(0, 0, 0, 0, LORIEBUFFER_AHARDWAREBUFFER, buffer, -1, 0, 0);
 }
 
+__LIBC_HIDDEN__ void LorieBuffer_convert(LorieBuffer* buffer, int8_t type, int8_t format) {
+    if (!buffer || buffer->desc.type != LORIEBUFFER_REGULAR
+        || (type != LORIEBUFFER_FD && type != LORIEBUFFER_AHARDWAREBUFFER)
+        || (format != AHARDWAREBUFFER_FORMAT_R8G8B8X8_UNORM && format != AHARDWAREBUFFER_FORMAT_B8G8R8A8_UNORM))
+        return;
+
+    if (type == LORIEBUFFER_FD) {
+        size_t size = alignToPage(buffer->desc.stride * buffer->desc.height * sizeof(uint32_t));
+        int fd = LorieBuffer_createRegion("LorieBuffer", size);
+        void *data;
+        if (fd < 0)
+            return;
+
+        data = mmap(NULL, size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+        if (!data || data == MAP_FAILED) {
+            close(fd);
+            return;
+        }
+
+        buffer->desc.type = type;
+        buffer->desc.format = format;
+        buffer->fd = fd;
+        buffer->size = size;
+        buffer->offset = 0;
+        free(buffer->desc.data);
+        buffer->desc.data = data;
+
+        buffer->lockedData = NULL;
+        buffer->locked = 0;
+    } else {
+        AHardwareBuffer *b = NULL;
+        AHardwareBuffer_Desc desc = { .width = buffer->desc.width, .height = buffer->desc.height, .format = format, .layers = 1,
+                .usage = AHARDWAREBUFFER_USAGE_CPU_READ_OFTEN | AHARDWAREBUFFER_USAGE_CPU_WRITE_OFTEN | AHARDWAREBUFFER_USAGE_GPU_SAMPLED_IMAGE };
+        int err = AHardwareBuffer_allocate(&desc, &b);
+        if (err != 0)
+            return;
+
+        AHardwareBuffer_describe(b, &desc);
+
+        buffer->desc.type = type;
+        buffer->desc.format = format;
+        buffer->desc.stride = desc.stride;
+        buffer->desc.buffer = b;
+        free(buffer->desc.data);
+        buffer->desc.data = NULL;
+        buffer->lockedData = NULL;
+        buffer->locked = 0;
+    }
+}
+
 __LIBC_HIDDEN__ void __LorieBuffer_free(LorieBuffer* buffer) {
     if (!buffer)
         return;

app/src/main/cpp/lorie/buffer.h

@@ -68,6 +68,15 @@ LorieBuffer* _Nullable LorieBuffer_wrapFileDescriptor(int32_t width, int32_t str
  */
 LorieBuffer* _Nullable LorieBuffer_wrapAHardwareBuffer(AHardwareBuffer* _Nullable buffer);
 
+/**
+ * Convert regular buffer to given type.
+ *
+ * @param buffer
+ * @param type
+ * @param format
+ */
+void LorieBuffer_convert(LorieBuffer* _Nullable buffer, int8_t type, int8_t format);
+
 /**
  * Acquire a reference on the given LorieBuffer object.
  *