From bffc012d16e5ccb6cfc5f00e92796b276a46f7f6 Mon Sep 17 00:00:00 2001
From: Hielke Morsink <hielke.morsink@gmail.com>
Date: Thu, 30 May 2019 14:34:20 +0200
Subject: [PATCH] Implement #1260: --transparent switch for screenshot command

---
 src/openrct2/cmdline/ScreenshotCommands.cpp           | 1 +
 src/openrct2/interface/Screenshot.cpp                 | 7 +++++++
 src/openrct2/interface/Screenshot.h                   | 1 +
 src/openrct2/interface/Viewport.h                     | 1 +
 src/openrct2/paint/tile_element/Paint.TileElement.cpp | 4 ++--
 5 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/openrct2/cmdline/ScreenshotCommands.cpp b/src/openrct2/cmdline/ScreenshotCommands.cpp
index a0ca954873..c0e8725ab7 100644
--- a/src/openrct2/cmdline/ScreenshotCommands.cpp
+++ b/src/openrct2/cmdline/ScreenshotCommands.cpp
@@ -24,6 +24,7 @@ static constexpr const CommandLineOptionDefinition ScreenshotOptionsDef[]
     { CMDLINE_TYPE_SWITCH,  &options.fix_vandalism, NAC, "fix-vandalism", "fix vandalism for the screenshot" },
     { CMDLINE_TYPE_SWITCH,  &options.remove_litter, NAC, "remove-litter", "remove litter for the screenshot" },
     { CMDLINE_TYPE_SWITCH,  &options.tidy_up_park,  NAC, "tidy-up-park",  "clear grass, water plants, fix vandalism and remove litter" },
+    { CMDLINE_TYPE_SWITCH,  &options.transparent,   NAC, "transparent",   "make the background transparent" },
     OptionTableEnd
 };
 
diff --git a/src/openrct2/interface/Screenshot.cpp b/src/openrct2/interface/Screenshot.cpp
index c9e22efee6..0a4bdd176a 100644
--- a/src/openrct2/interface/Screenshot.cpp
+++ b/src/openrct2/interface/Screenshot.cpp
@@ -562,6 +562,8 @@ int32_t cmdline_for_screenshot(const char** argv, int32_t argc, ScreenshotOption
     dpi.bits = (uint8_t*)malloc(dpi.width * dpi.height);
     dpi.DrawingEngine = context->GetDrawingEngine();
 
+    std::memset(dpi.bits, PALETTE_INDEX_0, dpi.width * dpi.height);
+
     if (options->hide_guests)
     {
         viewport.flags |= VIEWPORT_FLAG_INVISIBLE_PEEPS;
@@ -597,6 +599,11 @@ int32_t cmdline_for_screenshot(const char** argv, int32_t argc, ScreenshotOption
         CheatsSet(CheatType::RemoveLitter);
     }
 
+    if (options->transparent)
+    {
+        viewport.flags |= VIEWPORT_FLAG_TRANSPARENT_BACKGROUND;
+    }
+
     viewport_render(&dpi, &viewport, 0, 0, viewport.width, viewport.height);
 
     rct_palette renderedPalette;
diff --git a/src/openrct2/interface/Screenshot.h b/src/openrct2/interface/Screenshot.h
index 8e0b3c60ab..f0e29bf8ba 100644
--- a/src/openrct2/interface/Screenshot.h
+++ b/src/openrct2/interface/Screenshot.h
@@ -28,6 +28,7 @@ struct ScreenshotOptions
     bool fix_vandalism = false;
     bool remove_litter = false;
     bool tidy_up_park = false;
+    bool transparent = false;
 };
 
 void screenshot_check();
diff --git a/src/openrct2/interface/Viewport.h b/src/openrct2/interface/Viewport.h
index 8c0ebac2e4..ec5a567c68 100644
--- a/src/openrct2/interface/Viewport.h
+++ b/src/openrct2/interface/Viewport.h
@@ -46,6 +46,7 @@ enum
     VIEWPORT_FLAG_SEETHROUGH_PATHS = (1 << 16),
     VIEWPORT_FLAG_CLIP_VIEW = (1 << 17),
     VIEWPORT_FLAG_HIGHLIGHT_PATH_ISSUES = (1 << 18),
+    VIEWPORT_FLAG_TRANSPARENT_BACKGROUND = (1 << 19),
 };
 
 enum
diff --git a/src/openrct2/paint/tile_element/Paint.TileElement.cpp b/src/openrct2/paint/tile_element/Paint.TileElement.cpp
index 0632f8f7c0..baab66d438 100644
--- a/src/openrct2/paint/tile_element/Paint.TileElement.cpp
+++ b/src/openrct2/paint/tile_element/Paint.TileElement.cpp
@@ -57,7 +57,7 @@ void tile_element_paint_setup(paint_session* session, int32_t x, int32_t y)
 
         sub_68B3FB(session, x, y);
     }
-    else
+    else if (!(session->ViewFlags & VIEWPORT_FLAG_TRANSPARENT_BACKGROUND))
     {
         blank_tiles_paint(session, x, y);
     }
@@ -78,7 +78,7 @@ void sub_68B2B7(paint_session* session, int32_t x, int32_t y)
 
         sub_68B3FB(session, x, y);
     }
-    else
+    else if (!(session->ViewFlags & VIEWPORT_FLAG_TRANSPARENT_BACKGROUND))
     {
         blank_tiles_paint(session, x, y);
     }