From 8b8f827b70533cf70fab196e5f9a22bcb204738f Mon Sep 17 00:00:00 2001
From: Dav999 <dav999.tolp@gmail.com>
Date: Thu, 1 Aug 2024 23:38:55 +0200
Subject: [PATCH] Add IME text rendering

This shows the uncommitted text in a box in the bottom left corner.
This doesn't show the selection (defined by the start and length fields
in the event) yet, but this is already much better than it was on its
own, and I don't know how urgent the selection is since it's broken on
Windows anyway.
---
 desktop_version/CMakeLists.txt    |  1 +
 desktop_version/src/Graphics.cpp  | 10 ++++--
 desktop_version/src/IMERender.cpp | 57 +++++++++++++++++++++++++++++++
 desktop_version/src/IMERender.h   |  7 ++++
 4 files changed, 72 insertions(+), 3 deletions(-)
 create mode 100644 desktop_version/src/IMERender.cpp
 create mode 100644 desktop_version/src/IMERender.h

diff --git a/desktop_version/CMakeLists.txt b/desktop_version/CMakeLists.txt
index 0aec895e..28b4b4b8 100644
--- a/desktop_version/CMakeLists.txt
+++ b/desktop_version/CMakeLists.txt
@@ -82,6 +82,7 @@ set(VVV_CXX_SRC
     src/Graphics.cpp
     src/GraphicsResources.cpp
     src/GraphicsUtil.cpp
+    src/IMERender.cpp
     src/Input.cpp
     src/KeyPoll.cpp
     src/Labclass.cpp
diff --git a/desktop_version/src/Graphics.cpp b/desktop_version/src/Graphics.cpp
index 7d7489e5..0c2dba35 100644
--- a/desktop_version/src/Graphics.cpp
+++ b/desktop_version/src/Graphics.cpp
@@ -12,6 +12,7 @@
 #include "FileSystemUtils.h"
 #include "Font.h"
 #include "GraphicsUtil.h"
+#include "IMERender.h"
 #include "Localization.h"
 #include "Map.h"
 #include "Maths.h"
@@ -3529,6 +3530,7 @@ void Graphics::get_stretch_info(SDL_Rect* rect)
 
 void Graphics::render(void)
 {
+    ime_render();
     draw_screenshot_border();
 
     if (gameScreen.badSignalEffect)
@@ -3541,10 +3543,12 @@ void Graphics::render(void)
 
     draw_window_background();
 
-    SDL_Rect rect;
-    get_stretch_info(&rect);
+    SDL_Rect stretch_info;
+    get_stretch_info(&stretch_info);
 
-    copy_texture(gameTexture, NULL, &rect, 0, NULL, flipmode ? SDL_FLIP_VERTICAL : SDL_FLIP_NONE);
+    ime_set_rect(&stretch_info);
+
+    copy_texture(gameTexture, NULL, &stretch_info, 0, NULL, flipmode ? SDL_FLIP_VERTICAL : SDL_FLIP_NONE);
 }
 
 void Graphics::renderwithscreeneffects(void)
diff --git a/desktop_version/src/IMERender.cpp b/desktop_version/src/IMERender.cpp
new file mode 100644
index 00000000..dde7e37d
--- /dev/null
+++ b/desktop_version/src/IMERender.cpp
@@ -0,0 +1,57 @@
+#include <SDL.h>
+
+#include "Constants.h"
+#include "Font.h"
+#include "Graphics.h"
+#include "KeyPoll.h"
+
+static bool render_done = false;
+static SDL_Rect imebox;
+
+void ime_render(void)
+{
+    render_done = false;
+
+    if (!SDL_IsTextInputActive() || key.imebuffer == "")
+    {
+        return;
+    }
+
+    int fontheight = font::height(PR_FONT_LEVEL);
+    imebox.x = 8;
+    imebox.y = SCREEN_HEIGHT_PIXELS - 32 - fontheight;
+    imebox.w = font::len(PR_FONT_LEVEL, key.imebuffer.c_str()) + 1;
+    imebox.h = fontheight + 1;
+
+    SDL_Rect imebox_border = imebox;
+    imebox_border.x -= 1;
+    imebox_border.y -= 1;
+    imebox_border.w += 2;
+    imebox_border.h += 2;
+
+    graphics.fill_rect(&imebox_border, 128, 128, 128);
+    graphics.fill_rect(&imebox, 0, 0, 0);
+    font::print(PR_FONT_LEVEL | PR_CJK_LOW, imebox.x + 1, imebox.y + 1, key.imebuffer, 255, 255, 255);
+
+    render_done = true;
+}
+
+void ime_set_rect(SDL_Rect* stretch_info)
+{
+    if (!render_done)
+    {
+        return;
+    }
+
+    SDL_Rect imebox_scaled = imebox;
+    float x_scale = (float) stretch_info->w / SCREEN_WIDTH_PIXELS;
+    float y_scale = (float) stretch_info->h / SCREEN_HEIGHT_PIXELS;
+    imebox_scaled.x *= x_scale;
+    imebox_scaled.y *= y_scale;
+    imebox_scaled.w *= x_scale;
+    imebox_scaled.h *= y_scale;
+    imebox_scaled.x += stretch_info->x;
+    imebox_scaled.y += stretch_info->y;
+
+    SDL_SetTextInputRect(&imebox_scaled);
+}
diff --git a/desktop_version/src/IMERender.h b/desktop_version/src/IMERender.h
new file mode 100644
index 00000000..9e48ebd1
--- /dev/null
+++ b/desktop_version/src/IMERender.h
@@ -0,0 +1,7 @@
+#ifndef IMERENDER_H
+#define IMERENDER_H
+
+void ime_render(void);
+void ime_set_rect(SDL_Rect* stretch_info);
+
+#endif /* IMERENDER_H */