Handle screen orientation

config.txt

@@ -11,6 +11,7 @@ boot=MS
 #  - "n=(number)", a weight for this image in the randomization process. Default: n=1.
 #  - "x=(number)" or "x=keep", the x offset from the center. Default: x=0.
 #  - "y=(number)" or "y=keep", the y offset from the center. Default: y=0.
+#  - "o=(0|90|180|270|keep)", the screen orientation, degrees anticlockwise. Default: o=keep.
 # One of the following:
 #  - "keep" to keep the firmware logo. Also keeps coordinates by default.
 #  - "remove" to remove the BGRT. Makes x and y meaningless.
@@ -23,14 +24,14 @@ boot=MS
 #  - image=remove
 #  - image=black
 #  - image= x=0 y=-200 path=\EFI\HackBGRT\topimage.bmp
-#  - image=n=1,path=\EFI\HackBGRT\splash.bmp
+#  - image= n=1 o=90 path=\EFI\HackBGRT\sideways.bmp
-#  - image=n=50,path=\EFI\HackBGRT\probable.bmp
+#  - image= n=50 y=999999 o=keep path=\EFI\HackBGRT\probable.bmp
 # The above examples together would produce
 #  - 1/54 chance for the default OS logo
 #  - 1/54 chance for black screen
 #  - 1/54 chance for topimage.bmp, 200 px above the center of the screen
-#  - 1/54 chance for splash.bmp, automatically positioned
+#  - 1/54 chance for splash.bmp, centered, orientation set to 90 degrees
-#  - 50/54 chance for probable.bmp, automatically positioned
+#  - 50/54 chance for probable.bmp, at the bottom edge, explicitly default orientation
 # Default: just one image.
 image= y=-200 path=\EFI\HackBGRT\splash.bmp
 

src/config.c

@@ -70,16 +70,17 @@ BOOLEAN ReadConfigFile(struct HackBGRT_config* config, EFI_FILE_HANDLE root_dir,
 	return TRUE;
 }
 
-static void SetBMPWithRandom(struct HackBGRT_config* config, int weight, enum HackBGRT_action action, int x, int y, const CHAR16* path) {
+static void SetBMPWithRandom(struct HackBGRT_config* config, int weight, enum HackBGRT_action action, int x, int y, int o, const CHAR16* path) {
 	config->image_weight_sum += weight;
 	UINT32 random = Random();
 	UINT32 limit = 0xfffffffful / config->image_weight_sum * weight;
 	if (config->debug) {
-		Print(L"HackBGRT: weight %d, action %d, x %d, y %d, path %s, random = %08x, limit = %08x\n", weight, action, x, y, path, random, limit);
+		Print(L"HackBGRT: weight %d, action %d, x %d, y %d, o %d, path %s, random = %08x, limit = %08x\n", weight, action, x, y, o, path, random, limit);
 	}
 	if (!config->image_weight_sum || random <= limit) {
 		config->action = action;
 		config->image_path = path;
+		config->orientation = o;
 		config->image_x = x;
 		config->image_y = y;
 	}
@@ -99,6 +100,7 @@ static void ReadConfigImage(struct HackBGRT_config* config, const CHAR16* line)
 	const CHAR16* n = StrStrAfter(line, L"n=");
 	const CHAR16* x = StrStrAfter(line, L"x=");
 	const CHAR16* y = StrStrAfter(line, L"y=");
+	const CHAR16* o = StrStrAfter(line, L"o=");
 	const CHAR16* f = StrStrAfter(line, L"path=");
 	enum HackBGRT_action action = HackBGRT_KEEP;
 	if (f) {
@@ -114,7 +116,10 @@ static void ReadConfigImage(struct HackBGRT_config* config, const CHAR16* line)
 		return;
 	}
 	int weight = n && (!f || n < f) ? Atoi(n) : 1;
-	SetBMPWithRandom(config, weight, action, ParseCoordinate(x, action), ParseCoordinate(y, action), f);
+	int x_val = ParseCoordinate(x, action);
+	int y_val = ParseCoordinate(y, action);
+	int o_val = o ? ParseCoordinate(o, action) : HackBGRT_coord_keep;
+	SetBMPWithRandom(config, weight, action, x_val, y_val, o_val, f);
 }
 
 static void ReadConfigResolution(struct HackBGRT_config* config, const CHAR16* line) {

src/config.h

@@ -14,7 +14,7 @@ enum HackBGRT_action {
  * @see struct HackBGRT_config
  */
 enum HackBGRT_coordinate {
-	HackBGRT_coord_keep = -999999
+	HackBGRT_coord_keep = -1000000001
 };
 
 /**
@@ -27,6 +27,7 @@ struct HackBGRT_config {
 	int image_x;
 	int image_y;
 	int image_weight_sum;
+	int orientation;
 	int resolution_x;
 	int resolution_y;
 	int old_resolution_x;

src/main.c

@@ -248,8 +248,12 @@ void HackBgrt(EFI_FILE_HANDLE root_dir) {
 	// Get the old BMP and position (relative to screen center), if possible.
 	const int old_valid = bgrt && VerifyAcpiSdtChecksum(bgrt);
 	BMP* old_bmp = old_valid ? (BMP*) (UINTN) bgrt->image_address : 0;
-	const int old_x = old_bmp ? bgrt->image_offset_x + (old_bmp->width - config.old_resolution_x) / 2 : 0;
+	const int old_orientation = old_valid ? ((bgrt->status >> 1) & 3) : 0;
-	const int old_y = old_bmp ? bgrt->image_offset_y + (old_bmp->height - config.old_resolution_y) / 2 : 0;
+	const int old_swap = old_orientation & 1;
+	const int old_reso_x = old_swap ? config.old_resolution_y : config.old_resolution_x;
+	const int old_reso_y = old_swap ? config.old_resolution_x : config.old_resolution_y;
+	const int old_x = old_bmp ? bgrt->image_offset_x + (old_bmp->width - old_reso_x) / 2 : 0;
+	const int old_y = old_bmp ? bgrt->image_offset_y + (old_bmp->height - old_reso_y) / 2 : 0;
 
 	// Missing BGRT?
 	if (!bgrt) {
@@ -284,22 +288,29 @@ void HackBgrt(EFI_FILE_HANDLE root_dir) {
 		return;
 	}
 
+	// Set the image address and orientation.
 	bgrt->image_address = (UINTN) new_bmp;
+	const int new_orientation = config.orientation == HackBGRT_coord_keep ? old_orientation : ((config.orientation / 90) & 3);
+	bgrt->status = new_orientation << 1;
 
 	// New center coordinates.
 	const int new_x = config.image_x == HackBGRT_coord_keep ? old_x : config.image_x;
 	const int new_y = config.image_y == HackBGRT_coord_keep ? old_y : config.image_y;
+	const int new_swap = new_orientation & 1;
+	const int new_reso_x = new_swap ? config.resolution_y : config.resolution_x;
+	const int new_reso_y = new_swap ? config.resolution_x : config.resolution_y;
 
 	// Calculate absolute position.
-	const int max_x = config.resolution_x - new_bmp->width;
+	const int max_x = new_reso_x - new_bmp->width;
-	const int max_y = config.resolution_y - new_bmp->height;
+	const int max_y = new_reso_y - new_bmp->height;
-	bgrt->image_offset_x = max(0, min(max_x, new_x + (config.resolution_x - new_bmp->width) / 2));
+	bgrt->image_offset_x = max(0, min(max_x, new_x + (new_reso_x - new_bmp->width) / 2));
-	bgrt->image_offset_y = max(0, min(max_y, new_y + (config.resolution_y - new_bmp->height) / 2));
+	bgrt->image_offset_y = max(0, min(max_y, new_y + (new_reso_y - new_bmp->height) / 2));
 
 	Debug(
-		L"HackBGRT: BMP at (%d, %d), center (%d, %d), resolution (%d, %d).\n",
+		L"HackBGRT: BMP at (%d, %d), center (%d, %d), resolution (%d, %d) with orientation %d applied.\n",
 		(int) bgrt->image_offset_x, (int) bgrt->image_offset_y,
-		new_x, new_y, config.resolution_x, config.resolution_y
+		new_x, new_y, new_reso_x, new_reso_y,
+		new_orientation * 90
 	);
 
 	// Store this BGRT in the ACPI tables.