[PATCH xf86-video-amdgpu] Apply gamma correction to HW cursor

[Michel Dänzer]

From: Michel Dänzer <michel.daenzer at amd.com>

The display hardware CLUT we're currently using for gamma correction
doesn't affect the HW cursor, so we have to apply it manually when
uploading the HW cursor data.

This currently only works in depth 24/32.

Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
---
 src/drmmode_display.c | 66 ++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 58 insertions(+), 8 deletions(-)

diff --git a/src/drmmode_display.c b/src/drmmode_display.c
index 5e0c4133b..5b2431495 100644
--- a/src/drmmode_display.c
+++ b/src/drmmode_display.c
@@ -756,6 +756,17 @@ drmmode_crtc_scanout_update(xf86CrtcPtr crtc, DisplayModePtr mode,
 	}
 }
 
+static void
+drmmode_crtc_gamma_do_set(xf86CrtcPtr crtc, uint16_t *red, uint16_t *green,
+			  uint16_t *blue, int size)
+{
+	drmmode_crtc_private_ptr drmmode_crtc = crtc->driver_private;
+	AMDGPUEntPtr pAMDGPUEnt = AMDGPUEntPriv(crtc->scrn);
+
+	drmModeCrtcSetGamma(pAMDGPUEnt->fd, drmmode_crtc->mode_crtc->crtc_id,
+			    size, red, green, blue);
+}
+
 static Bool
 drmmode_set_mode_major(xf86CrtcPtr crtc, DisplayModePtr mode,
 		       Rotation rotation, int x, int y)
@@ -820,8 +831,8 @@ drmmode_set_mode_major(xf86CrtcPtr crtc, DisplayModePtr mode,
 		if (drmmode_crtc->tear_free)
 			scanout_id = drmmode_crtc->scanout_id;
 
-		crtc->funcs->gamma_set(crtc, crtc->gamma_red, crtc->gamma_green,
-				       crtc->gamma_blue, crtc->gamma_size);
+		drmmode_crtc_gamma_do_set(crtc, crtc->gamma_red, crtc->gamma_green,
+					  crtc->gamma_blue, crtc->gamma_size);
 
 		drmmode_ConvertToKMode(crtc->scrn, &kmode, mode);
 
@@ -991,6 +1002,31 @@ drmmode_cursor_src_offset(Rotation rotation, int width, int height,
 
 #endif
 
+static uint32_t
+drmmode_cursor_gamma(xf86CrtcPtr crtc, uint32_t argb)
+{
+	uint32_t alpha = argb >> 24;
+	uint32_t rgb[3];
+	int i;
+
+	if (!alpha)
+		return 0;
+
+	if (crtc->scrn->depth != 24 && crtc->scrn->depth != 32)
+		return argb;
+
+	/* Un-premultiply alpha */
+	for (i = 0; i < 3; i++)
+		rgb[i] = ((argb >> (i * 8)) & 0xff) * 0xff / alpha;
+
+	/* Apply gamma correction and pre-multiply alpha */
+	rgb[0] = (crtc->gamma_blue[rgb[0]] >> 8) * alpha / 0xff;
+	rgb[1] = (crtc->gamma_green[rgb[1]] >> 8) * alpha / 0xff;
+	rgb[2] = (crtc->gamma_red[rgb[2]] >> 8) * alpha / 0xff;
+
+	return alpha << 24 | rgb[2] << 16 | rgb[1] << 8 | rgb[0];
+}
+
 static void drmmode_do_load_cursor_argb(xf86CrtcPtr crtc, CARD32 *image, uint32_t *ptr)
 {
 	ScrnInfoPtr pScrn = crtc->scrn;
@@ -1010,7 +1046,8 @@ static void drmmode_do_load_cursor_argb(xf86CrtcPtr crtc, CARD32 *image, uint32_
 								      dstx, dsty);
 
 				ptr[dsty * info->cursor_w + dstx] =
-					cpu_to_le32(image[srcoffset]);
+					cpu_to_le32(drmmode_cursor_gamma(crtc,
+									 image[srcoffset]));
 			}
 		}
 	} else
@@ -1020,7 +1057,7 @@ static void drmmode_do_load_cursor_argb(xf86CrtcPtr crtc, CARD32 *image, uint32_
 		int i;
 
 		for (i = 0; i < cursor_size; i++)
-			ptr[i] = cpu_to_le32(image[i]);
+			ptr[i] = cpu_to_le32(drmmode_cursor_gamma(crtc, image[i]));
 	}
 }
 
@@ -1176,11 +1213,24 @@ static void
 drmmode_crtc_gamma_set(xf86CrtcPtr crtc, uint16_t * red, uint16_t * green,
 		       uint16_t * blue, int size)
 {
-	drmmode_crtc_private_ptr drmmode_crtc = crtc->driver_private;
-	AMDGPUEntPtr pAMDGPUEnt = AMDGPUEntPriv(crtc->scrn);
+	ScrnInfoPtr scrn = crtc->scrn;
+	xf86CrtcConfigPtr xf86_config = XF86_CRTC_CONFIG_PTR(scrn);
+	AMDGPUInfoPtr info = AMDGPUPTR(scrn);
+	int i;
 
-	drmModeCrtcSetGamma(pAMDGPUEnt->fd, drmmode_crtc->mode_crtc->crtc_id,
-			    size, red, green, blue);
+	drmmode_crtc_gamma_do_set(crtc, red, green, blue, size);
+
+	/* Compute index of this CRTC into xf86_config->crtc */
+	for (i = 0; xf86_config->crtc[i] != crtc; i++) {}
+
+	if (info->hwcursor_disabled & (1 << i))
+		return;
+
+#ifdef HAVE_XF86_CURSOR_RESET_CURSOR
+	xf86CursorResetCursor(scrn->pScreen);
+#else
+	xf86_reload_cursors(scrn->pScreen);
+#endif
 }
 
 #ifdef AMDGPU_PIXMAP_SHARING
-- 
2.11.0