On Tue, 18 Nov 2025, Chad Jablonski wrote:
A large amount of the common setup involved in a blit deals with the
destination. This moves that setup to a helper function returning a
struct (ATIBlitDest) holding all of that state. The idea here is that
this setup will be shared between blits from memory as well as from
HOST_DATA and maybe others in the future.
The next patch refactors ati_2d_blt to use this new helper.
Maybe better to squash in next patch to make it easier to see code
movement.
Regards,
BALATON Zoltan
Signed-off-by: Chad Jablonski <[email protected]>
---
hw/display/ati_2d.c | 54 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)
diff --git a/hw/display/ati_2d.c b/hw/display/ati_2d.c
index 9c96ee155f..f2e01e28e9 100644
--- a/hw/display/ati_2d.c
+++ b/hw/display/ati_2d.c
@@ -67,6 +67,60 @@ static QemuRect sc_rect(ATIVGAState *s)
return sc;
}
+typedef struct {
+ QemuRect rect;
+ QemuRect visible;
+ uint32_t src_left_offset;
+ uint32_t src_top_offset;
+ int bpp;
+ int stride;
+ bool top_to_bottom;
+ bool left_to_right;
+ bool valid;
+ uint8_t *bits;
+} ATIBlitDest;
+
+static ATIBlitDest setup_2d_blt_dst(ATIVGAState *s)
+{
+ ATIBlitDest dst = { .valid = false };
+ uint8_t *end = s->vga.vram_ptr + s->vga.vram_size;
+ QemuRect scissor = sc_rect(s);
+
+ dst.rect = dst_rect(s);
+ if (!qemu_rect_intersect(&dst.rect, &scissor, &dst.visible)) {
+ /* Destination is completely clipped, nothing to draw */
+ return dst;
+ }
+ dst.bpp = ati_bpp_from_datatype(s);
+ if (!dst.bpp) {
+ qemu_log_mask(LOG_GUEST_ERROR, "Invalid bpp\n");
+ return dst;
+ }
+ dst.stride = s->regs.dst_pitch;
+ if (!dst.stride) {
+ qemu_log_mask(LOG_GUEST_ERROR, "Zero dest pitch\n");
+ return dst;
+ }
+ dst.bits = s->vga.vram_ptr + s->regs.dst_offset;
+ if (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF) {
+ dst.bits += s->regs.crtc_offset & 0x07ffffff;
+ dst.stride *= dst.bpp;
+ }
+ if (dst.visible.x > 0x3fff || dst.visible.y > 0x3fff || dst.bits >= end
+ || dst.bits + dst.visible.x
+ + (dst.visible.y + dst.visible.height) * dst.stride >= end) {
+ qemu_log_mask(LOG_UNIMP, "blt outside vram not implemented\n");
+ return dst;
+ }
+ dst.src_left_offset = dst.visible.x - dst.rect.x;
+ dst.src_top_offset = dst.visible.y - dst.rect.y;
+ dst.left_to_right = s->regs.dp_cntl & DST_X_LEFT_TO_RIGHT;
+ dst.top_to_bottom = s->regs.dp_cntl & DST_Y_TOP_TO_BOTTOM;
+ dst.valid = true;
+
+ return dst;
+}
+
void ati_2d_blt(ATIVGAState *s)
{
/* FIXME it is probably more complex than this and may need to be */
