4 files changed, 47 insertions, 4 deletions

diff --git a/src/blitter/32bpp_anim.cpp b/src/blitter/32bpp_anim.cpp
index 40bf358db..6af9926e1 100644
--- a/src/blitter/32bpp_anim.cpp
+++ b/src/blitter/32bpp_anim.cpp
@@ -13,7 +13,7 @@ static FBlitter_32bppAnim iFBlitter_32bppAnim;
 
 void Blitter_32bppAnim::Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom)
 {
-	if (bp->dst < _screen.dst_ptr || bp->dst > (uint32 *)_screen.dst_ptr + _screen.width * _screen.height) {
+	if (_screen_disable_anim) {
 		/* This means our output is not to the screen, so we can't be doing any animation stuff, so use our parent Draw() */
 		Blitter_32bppOptimized::Draw(bp, mode, zoom);
 		return;
@@ -98,6 +98,12 @@ void Blitter_32bppAnim::Draw(Blitter::BlitterParams *bp, BlitterMode mode, ZoomL
 
 void Blitter_32bppAnim::DrawColorMappingRect(void *dst, int width, int height, int pal)
 {
+	if (_screen_disable_anim) {
+		/* This means our output is not to the screen, so we can't be doing any animation stuff, so use our parent DrawColorMappingRect() */
+		Blitter_32bppOptimized::DrawColorMappingRect(dst, width, height, pal);
+		return;
+	}
+
 	uint32 *udst = (uint32 *)dst;
 	uint8 *anim;
 
@@ -136,7 +142,9 @@ void Blitter_32bppAnim::DrawColorMappingRect(void *dst, int width, int height, i
 void Blitter_32bppAnim::SetPixel(void *video, int x, int y, uint8 color)
 {
 	*((uint32 *)video + x + y * _screen.pitch) = LookupColourInPalette(color);
-	/* Set the color in the anim-buffer too */
+
+	/* Set the color in the anim-buffer too, if we are rendering to the screen */
+	if (_screen_disable_anim) return;
 	this->anim_buf[((uint32 *)video - (uint32 *)_screen.dst_ptr) + x + y * this->anim_buf_width] = color;
 }
 
@@ -145,13 +153,20 @@ void Blitter_32bppAnim::SetPixelIfEmpty(void *video, int x, int y, uint8 color)
 	uint32 *dst = (uint32 *)video + x + y * _screen.pitch;
 	if (*dst == 0) {
 		*dst = LookupColourInPalette(color);
-		/* Set the color in the anim-buffer too */
+		/* Set the color in the anim-buffer too, if we are rendering to the screen */
+		if (_screen_disable_anim) return;
 		this->anim_buf[((uint32 *)video - (uint32 *)_screen.dst_ptr) + x + y * this->anim_buf_width] = color;
 	}
 }
 
 void Blitter_32bppAnim::DrawRect(void *video, int width, int height, uint8 color)
 {
+	if (_screen_disable_anim) {
+		/* This means our output is not to the screen, so we can't be doing any animation stuff, so use our parent DrawRect() */
+		Blitter_32bppOptimized::DrawRect(video, width, height, color);
+		return;
+	}
+
 	uint32 color32 = LookupColourInPalette(color);
 	uint8 *anim_line;
 
@@ -175,6 +190,7 @@ void Blitter_32bppAnim::DrawRect(void *video, int width, int height, uint8 color
 
 void Blitter_32bppAnim::CopyFromBuffer(void *video, const void *src, int width, int height)
 {
+	assert(!_screen_disable_anim);
 	assert(video >= _screen.dst_ptr && video <= (uint32 *)_screen.dst_ptr + _screen.width + _screen.height * _screen.pitch);
 	uint32 *dst = (uint32 *)video;
 	uint32 *usrc = (uint32 *)src;
@@ -198,6 +214,7 @@ void Blitter_32bppAnim::CopyFromBuffer(void *video, const void *src, int width,
 
 void Blitter_32bppAnim::CopyToBuffer(const void *video, void *dst, int width, int height)
 {
+	assert(!_screen_disable_anim);
 	assert(video >= _screen.dst_ptr && video <= (uint32 *)_screen.dst_ptr + _screen.width + _screen.height * _screen.pitch);
 	uint32 *udst = (uint32 *)dst;
 	uint32 *src = (uint32 *)video;
@@ -220,6 +237,8 @@ void Blitter_32bppAnim::CopyToBuffer(const void *video, void *dst, int width, in
 
 void Blitter_32bppAnim::ScrollBuffer(void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y)
 {
+	assert(!_screen_disable_anim);
+	assert(video >= _screen.dst_ptr && video <= (uint32 *)_screen.dst_ptr + _screen.width + _screen.height * _screen.pitch);
 	uint8 *dst, *src;
 
 	/* We need to scroll the anim-buffer too */
@@ -268,6 +287,7 @@ int Blitter_32bppAnim::BufferSize(int width, int height)
 
 void Blitter_32bppAnim::PaletteAnimate(uint start, uint count)
 {
+	assert(!_screen_disable_anim);
 	uint8 *anim = this->anim_buf;
 
 	/* Never repaint the transparency pixel */
diff --git a/src/gfx.cpp b/src/gfx.cpp
index 322c450dd..8f2717e1f 100644
--- a/src/gfx.cpp
+++ b/src/gfx.cpp
@@ -31,6 +31,7 @@ bool _left_button_clicked;
 bool _right_button_down;
 bool _right_button_clicked;
 DrawPixelInfo _screen;
+bool _screen_disable_anim = false;   ///< Disable palette animation (important for 32bpp-anim blitter during giant screenshot)
 bool _exit_game;
 bool _networking;         ///< are we in networking mode?
 byte _game_mode;
diff --git a/src/gfx_func.h b/src/gfx_func.h
index 0103e7044..a4033caed 100644
--- a/src/gfx_func.h
+++ b/src/gfx_func.h
@@ -55,6 +55,7 @@ extern bool _right_button_down;
 extern bool _right_button_clicked;
 
 extern DrawPixelInfo _screen;
+extern bool _screen_disable_anim;   ///< Disable palette animation (important for 32bpp-anim blitter during giant screenshot)
 
 extern int _pal_first_dirty;
 extern int _pal_count_dirty;
diff --git a/src/screenshot.cpp b/src/screenshot.cpp
index c20512d6c..822a3e0cf 100644
--- a/src/screenshot.cpp
+++ b/src/screenshot.cpp
@@ -488,13 +488,29 @@ static void CurrentScreenCallback(void *userdata, void *buf, uint y, uint pitch,
 	blitter->CopyImageToBuffer(src, buf, _screen.width, n, pitch);
 }
 
-/* generate a large piece of the world */
+/** generate a large piece of the world
+ * @param userdata Viewport area to draw
+ * @param buf Videobuffer with same bitdepth as current blitter
+ * @param y First line to render
+ * @param pitch Pitch of the videobuffer
+ * @param n Number of lines to render
+ */
 static void LargeWorldCallback(void *userdata, void *buf, uint y, uint pitch, uint n)
 {
 	ViewPort *vp = (ViewPort *)userdata;
 	DrawPixelInfo dpi, *old_dpi;
 	int wx, left;
 
+	/* We are no longer rendering to the screen */
+	DrawPixelInfo old_screen = _screen;
+	bool old_disable_anim = _screen_disable_anim;
+
+	_screen.dst_ptr = buf;
+	_screen.width = pitch;
+	_screen.height = n;
+	_screen.pitch = pitch;
+	_screen_disable_anim = true;
+
 	old_dpi = _cur_dpi;
 	_cur_dpi = &dpi;
 
@@ -506,6 +522,7 @@ static void LargeWorldCallback(void *userdata, void *buf, uint y, uint pitch, ui
 	dpi.left = 0;
 	dpi.top = y;
 
+	/* Render viewport in blocks of 1600 pixels width */
 	left = 0;
 	while (vp->width - left != 0) {
 		wx = min(vp->width - left, 1600);
@@ -520,6 +537,10 @@ static void LargeWorldCallback(void *userdata, void *buf, uint y, uint pitch, ui
 	}
 
 	_cur_dpi = old_dpi;
+
+	/* Switch back to rendering to the screen */
+	_screen = old_screen;
+	_screen_disable_anim = old_disable_anim;
 }
 
 static char *MakeScreenshotName(const char *ext)