ati-vga: Fix reverse bit blts

The pixman library only supports blts with left to right, top to
bottom order but the ATI VGA engine can also do different directions.
Fix support for these via a temporary buffer for now. This fixes
rendering issues related to such blts (such as moving windows) but
some other glitches still remain.

Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Message-id: e21855faaeb30d7b1771f084f283f6a30bedb1a3.1562227303.git.balaton@eik.bme.hu
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

hw/display/ati_2d.c

@@ -53,6 +53,10 @@ void ati_2d_blt(ATIVGAState *s)
             s->vga.vbe_start_addr, surface_data(ds), surface_stride(ds),
             surface_bits_per_pixel(ds),
             (s->regs.dp_mix & GMC_ROP3_MASK) >> 16);
+    int dst_x = (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT ?
+                 s->regs.dst_x : s->regs.dst_x + 1 - s->regs.dst_width);
+    int dst_y = (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ?
+                 s->regs.dst_y : s->regs.dst_y + 1 - s->regs.dst_height);
     int bpp = ati_bpp_from_datatype(s);
     int dst_stride = DEFAULT_CNTL ? s->regs.dst_pitch : s->regs.default_pitch;
     uint8_t *dst_bits = s->vga.vram_ptr + (DEFAULT_CNTL ?
@@ -63,20 +67,25 @@ void ati_2d_blt(ATIVGAState *s)
         dst_stride *= bpp;
     }
     uint8_t *end = s->vga.vram_ptr + s->vga.vram_size;
-    if (dst_bits >= end ||
-        dst_bits + s->regs.dst_x + (s->regs.dst_y + s->regs.dst_height) *
+    if (dst_bits >= end || dst_bits + dst_x + (dst_y + s->regs.dst_height) *
         dst_stride >= end) {
         qemu_log_mask(LOG_UNIMP, "blt outside vram not implemented\n");
         return;
     }
-    DPRINTF("%d %d %d, %d %d %d, (%d,%d) -> (%d,%d) %dx%d\n",
+    DPRINTF("%d %d %d, %d %d %d, (%d,%d) -> (%d,%d) %dx%d %c %c\n",
             s->regs.src_offset, s->regs.dst_offset, s->regs.default_offset,
             s->regs.src_pitch, s->regs.dst_pitch, s->regs.default_pitch,
             s->regs.src_x, s->regs.src_y, s->regs.dst_x, s->regs.dst_y,
-            s->regs.dst_width, s->regs.dst_height);
+            s->regs.dst_width, s->regs.dst_height,
+            (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT ? '>' : '<'),
+            (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ? 'v' : '^'));
     switch (s->regs.dp_mix & GMC_ROP3_MASK) {
     case ROP3_SRCCOPY:
     {
+        int src_x = (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT ?
+                     s->regs.src_x : s->regs.src_x + 1 - s->regs.dst_width);
+        int src_y = (s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM ?
+                     s->regs.src_y : s->regs.src_y + 1 - s->regs.dst_height);
         int src_stride = DEFAULT_CNTL ?
                          s->regs.src_pitch : s->regs.default_pitch;
         uint8_t *src_bits = s->vga.vram_ptr + (DEFAULT_CNTL ?
@@ -86,9 +95,8 @@ void ati_2d_blt(ATIVGAState *s)
             src_bits += s->regs.crtc_offset & 0x07ffffff;
             src_stride *= bpp;
         }
-        if (src_bits >= end ||
-            src_bits + s->regs.src_x + (s->regs.src_y + s->regs.dst_height) *
-            src_stride >= end) {
+        if (src_bits >= end || src_bits + src_x +
+            (src_y + s->regs.dst_height) * src_stride >= end) {
             qemu_log_mask(LOG_UNIMP, "blt outside vram not implemented\n");
             return;
         }
@@ -97,19 +105,36 @@ void ati_2d_blt(ATIVGAState *s)
         dst_stride /= sizeof(uint32_t);
         DPRINTF("pixman_blt(%p, %p, %d, %d, %d, %d, %d, %d, %d, %d, %d, %d)\n",
                 src_bits, dst_bits, src_stride, dst_stride, bpp, bpp,
-                s->regs.src_x, s->regs.src_y, s->regs.dst_x, s->regs.dst_y,
+                src_x, src_y, dst_x, dst_y,
                 s->regs.dst_width, s->regs.dst_height);
-        pixman_blt((uint32_t *)src_bits, (uint32_t *)dst_bits,
-                   src_stride, dst_stride, bpp, bpp,
-                   s->regs.src_x, s->regs.src_y,
-                   s->regs.dst_x, s->regs.dst_y,
-                   s->regs.dst_width, s->regs.dst_height);
+        if (s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT &&
+            s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM) {
+            pixman_blt((uint32_t *)src_bits, (uint32_t *)dst_bits,
+                       src_stride, dst_stride, bpp, bpp,
+                       src_x, src_y, dst_x, dst_y,
+                       s->regs.dst_width, s->regs.dst_height);
+        } else {
+            /* FIXME: We only really need a temporary if src and dst overlap */
+            int llb = s->regs.dst_width * (bpp / 8);
+            int tmp_stride = DIV_ROUND_UP(llb, sizeof(uint32_t));
+            uint32_t *tmp = g_malloc(tmp_stride * sizeof(uint32_t) *
+                                     s->regs.dst_height);
+            pixman_blt((uint32_t *)src_bits, tmp,
+                       src_stride, tmp_stride, bpp, bpp,
+                       src_x, src_y, 0, 0,
+                       s->regs.dst_width, s->regs.dst_height);
+            pixman_blt(tmp, (uint32_t *)dst_bits,
+                       tmp_stride, dst_stride, bpp, bpp,
+                       0, 0, dst_x, dst_y,
+                       s->regs.dst_width, s->regs.dst_height);
+            g_free(tmp);
+        }
         if (dst_bits >= s->vga.vram_ptr + s->vga.vbe_start_addr &&
             dst_bits < s->vga.vram_ptr + s->vga.vbe_start_addr +
             s->vga.vbe_regs[VBE_DISPI_INDEX_YRES] * s->vga.vbe_line_offset) {
             memory_region_set_dirty(&s->vga.vram, s->vga.vbe_start_addr +
                                     s->regs.dst_offset +
-                                    s->regs.dst_y * surface_stride(ds),
+                                    dst_y * surface_stride(ds),
                                     s->regs.dst_height * surface_stride(ds));
         }
         s->regs.dst_x += s->regs.dst_width;
@@ -151,7 +176,7 @@ void ati_2d_blt(ATIVGAState *s)
             s->vga.vbe_regs[VBE_DISPI_INDEX_YRES] * s->vga.vbe_line_offset) {
             memory_region_set_dirty(&s->vga.vram, s->vga.vbe_start_addr +
                                     s->regs.dst_offset +
-                                    s->regs.dst_y * surface_stride(ds),
+                                    dst_y * surface_stride(ds),
                                     s->regs.dst_height * surface_stride(ds));
         }
         s->regs.dst_y += s->regs.dst_height;