From 9576d6235e2b4cd2f6306b9ddd1cfb81019ee086 Mon Sep 17 00:00:00 2001
From: Lemur42332543632 <120027513+Lemur42332543632@users.noreply.github.com>
Date: Thu, 7 Nov 2024 22:11:10 +0300
Subject: [PATCH] Add VDP_drawTextClear function

---
 inc/vdp_bg.h | 23 +++++++++++++++++++++++
 src/vdp_bg.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+)

diff --git a/inc/vdp_bg.h b/inc/vdp_bg.h
index 8ccb78927..15a8194be 100644
--- a/inc/vdp_bg.h
+++ b/inc/vdp_bg.h
@@ -502,6 +502,29 @@ void VDP_clearTextLineBG(VDPPlane plane, u16 y);
  *  \see VDP_setTextPlane(..)
  */
 void VDP_drawText(const char *str, u16 x, u16 y);
+
+/**
+ *  \brief
+ *      Clears the field of characters and draws new text.<br>
+ *      If the new line is shorter than the one previously drawn in this place, the old characters will be removed.<br>
+ *      This function works significantly faster than calling VDP_clearText() and then VDP_drawText(). It is suitable when a lot of updating information needs to be displayed on the screen.
+ *
+ *  \param str
+ *      String to draw. For correct operation, it must not exceed 20 characters.
+ *  \param maxLength
+ *      Maximum string length. For correct operation, it must not exceed 20 characters.
+ *  \param x
+ *      X position (in tile).
+ *  \param y
+ *      y position (in tile).
+ *
+ *  \see VDP_drawText(..)
+ *  \see VDP_clearText(..)
+ *  \see VDP_setTextPalette(..)
+ *  \see VDP_setTextPriority(..)
+ *  \see VDP_setTextPlane(..)
+ */
+void VDP_drawTextClear(const char* str, u8 maxLength, u16 x, u16 y);
 /**
  *  \brief
  *      Clear a single line portion of text.
diff --git a/src/vdp_bg.c b/src/vdp_bg.c
index bfafed98d..ce392a7aa 100644
--- a/src/vdp_bg.c
+++ b/src/vdp_bg.c
@@ -382,6 +382,51 @@ void VDP_drawText(const char *str, u16 x, u16 y)
     VDP_drawTextBG(text_plan, str, x, y);
 }
 
+void VDP_drawTextClear(const char* str, u8 maxLength, u16 x, u16 y)
+{
+    static const char *spaceStrings[] = {
+        "",
+        " ",
+        "  ",
+        "   ",
+        "    ",
+        "     ",
+        "      ",
+        "       ",
+        "        ",
+        "         ",
+        "          ",
+        "           ",
+        "            ",
+        "             ",
+        "              ",
+        "               ",
+        "                ",
+        "                 ",
+        "                  ",
+        "                   ",
+        "                    "
+    };
+    char result[maxLength + 1];
+    char *spaces = spaceStrings[maxLength - strlen(str)];
+    char *dst = result;
+    const char *src;
+
+    src = str;
+    while (*src) {
+        *dst++ = *src++;
+    }
+    
+    src = spaces;
+    while (*src) {
+        *dst++ = *src++;
+    }
+
+    *dst = '\0';
+
+    VDP_drawText(result, x, y);
+}
+
 void VDP_clearText(u16 x, u16 y, u16 w)
 {
     VDP_clearTextBG(text_plan, x, y, w);