From 418169aff8faf2cf90124cd95dba0af821cea73d Mon Sep 17 00:00:00 2001
From: Solomon Peachy <pizza@shaftnet.org>
Date: Thu, 13 Oct 2022 11:03:53 -0400
Subject: Revert "Remove YUV blitting functions and LCD modes"

This reverts commit fe6aa21e9eb88f49005863efd2003d0982920048.

Change-Id: I8bb1e5d6c52ed1478002d2140ef494ec5d62b8e3
---
 firmware/target/arm/samsung/yh820/lcd-yh820.c | 74 +++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)

(limited to 'firmware/target/arm/samsung/yh820/lcd-yh820.c')

diff --git a/firmware/target/arm/samsung/yh820/lcd-yh820.c b/firmware/target/arm/samsung/yh820/lcd-yh820.c
index 25692eb8ac..f4b55ab917 100644
--- a/firmware/target/arm/samsung/yh820/lcd-yh820.c
+++ b/firmware/target/arm/samsung/yh820/lcd-yh820.c
@@ -30,6 +30,8 @@
 #endif
 
 /* Display status */
+static unsigned lcd_yuv_options SHAREDBSS_ATTR = 0;
+
 #if defined(HAVE_LCD_ENABLE) || defined(HAVE_LCD_SLEEP)
 static bool is_lcd_enabled = true;
 #endif
@@ -289,6 +291,78 @@ void lcd_set_flip(bool yesno)
 
 /*** update functions ***/
 
+void lcd_yuv_set_options(unsigned options)
+{
+    lcd_yuv_options = options;
+}
+
+/* Line write helper function for lcd_yuv_blit. Write two lines of yuv420. */
+extern void lcd_write_yuv420_lines(unsigned char const * const src[3],
+                                   int width,
+                                   int stride);
+extern void lcd_write_yuv420_lines_odither(unsigned char const * const src[3],
+                                           int width,
+                                           int stride,
+                                           int x_screen, /* To align dither pattern */
+                                           int y_screen);
+/* Performance function to blit a YUV bitmap directly to the LCD */
+void lcd_blit_yuv(unsigned char * const src[3],
+                  int src_x, int src_y, int stride,
+                  int x, int y, int width, int height)
+{
+    unsigned char const * yuv_src[3];
+    off_t z;
+
+    /* Sorry, but width and height must be >= 2 or else */
+    width &= ~1;
+    height >>= 1;
+    
+    z = stride*src_y;
+    yuv_src[0] = src[0] + z + src_x;
+    yuv_src[1] = src[1] + (z >> 2) + (src_x >> 1);
+    yuv_src[2] = src[2] + (yuv_src[1] - src[1]);
+
+    lcd_send_command(R_ENTRY_MODE);
+    lcd_send_command(0x03);
+
+    lcd_send_command(R_Y_ADDR_AREA);
+    lcd_send_command(x + 4);
+    lcd_send_command(x + width - 1 + 4);
+
+    if (lcd_yuv_options & LCD_YUV_DITHER)
+    {
+        do
+        {
+            lcd_send_command(R_X_ADDR_AREA);
+            lcd_send_command(y);
+            lcd_send_command(y + 1);
+
+            lcd_write_yuv420_lines_odither(yuv_src, width, stride, x, y);
+            yuv_src[0] += stride << 1; /* Skip down two luma lines */
+            yuv_src[1] += stride >> 1; /* Skip down one chroma line */
+            yuv_src[2] += stride >> 1;
+            y += 2;
+        }
+         while (--height > 0);
+    }
+    else
+    {
+        do
+        {
+            lcd_send_command(R_X_ADDR_AREA);
+            lcd_send_command(y);
+            lcd_send_command(y + 1);
+
+            lcd_write_yuv420_lines(yuv_src, width, stride);
+            yuv_src[0] += stride << 1; /* Skip down two luma lines */
+            yuv_src[1] += stride >> 1; /* Skip down one chroma line */
+            yuv_src[2] += stride >> 1;
+            y += 2;
+        }
+         while (--height > 0);
+    }
+}
+
 /* Update the display.
    This must be called after all other LCD functions that change the display. */
 void lcd_update(void)
-- 
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