BGE: Save screenshots in a different thread

This patch allows the game engine to keep running while performing things like PNG compression and disk I/O.

As an example, my crowd simulation rasterizer saves a screenshot for every frame. This now takes up 13 msec per frame, which was 31 msec before this patch. Effectively, it allows the simulation to save every frame and still run at 60 FPS.

Reviewers: lordloki, moguri, panzergame

Reviewed By: moguri, panzergame

Projects: #game_engine

Differential Revision: https://developer.blender.org/D1507

2 files changed, 17 insertions, 38 deletions

diff --git a/source/gameengine/BlenderRoutines/KX_BlenderCanvas.cpp b/source/gameengine/BlenderRoutines/KX_BlenderCanvas.cpp
index e37818678d6..927b26faf8a 100644
--- a/source/gameengine/BlenderRoutines/KX_BlenderCanvas.cpp
+++ b/source/gameengine/BlenderRoutines/KX_BlenderCanvas.cpp
@@ -35,23 +35,16 @@
 
 #include "KX_BlenderCanvas.h"
 
-#include "DNA_image_types.h"
-#include "DNA_scene_types.h"
 #include "DNA_screen_types.h"
+#include "DNA_scene_types.h"
 #include "DNA_windowmanager_types.h"
 
 #include "BKE_image.h"
-#include "BKE_global.h"
-#include "BKE_main.h"
-
-#include "BLI_path_util.h"
-#include "BLI_string.h"
 
 #include <assert.h>
+#include <iostream>
 
 extern "C" {
-#include "IMB_imbuf.h"
-#include "IMB_imbuf_types.h"
 #include "WM_api.h"
 #include "wm_cursors.h"
 #include "wm_window.h"
@@ -341,33 +334,20 @@ void KX_BlenderCanvas::MakeScreenShot(const char *filename)
 	area_dummy.totrct.ymax = m_frame_rect.GetTop();
 
 	dumprect = screenshot(&area_dummy, &dumpsx, &dumpsy);
-
-	if (dumprect) {
-		/* initialize image file format data */
-		Scene *scene = (screen)? screen->scene: NULL;
-		ImageFormatData im_format;
-
-		if (scene)
-			im_format = scene->r.im_format;
-		else
-			BKE_imformat_defaults(&im_format);
-
-		/* create file path */
-		char path[FILE_MAX];
-		BLI_strncpy(path, filename, sizeof(path));
-		BLI_path_abs(path, G.main->name);
-		BLI_path_frame(path, m_frame, 0);
-		m_frame++;
-		BKE_image_path_ensure_ext_from_imtype(path, im_format.imtype);
-
-		/* create and save imbuf */
-		ImBuf *ibuf = IMB_allocImBuf(dumpsx, dumpsy, 24, 0);
-		ibuf->rect = dumprect;
-
-		BKE_imbuf_write_as(ibuf, path, &im_format, false);
-
-		ibuf->rect = NULL;
-		IMB_freeImBuf(ibuf);
-		MEM_freeN(dumprect);
+	if (!dumprect) {
+		std::cerr << "KX_BlenderCanvas: Unable to take screenshot!" << std::endl;
+		return;
 	}
+
+	/* initialize image file format data */
+	Scene *scene = (screen)? screen->scene: NULL;
+	ImageFormatData *im_format = (ImageFormatData *)MEM_mallocN(sizeof(ImageFormatData), "im_format");
+
+	if (scene)
+		*im_format = scene->r.im_format;
+	else
+		BKE_imformat_defaults(im_format);
+
+	/* save_screenshot() frees dumprect and im_format */
+	save_screenshot(filename, dumpsx, dumpsy, dumprect, im_format);
 }
diff --git a/source/gameengine/BlenderRoutines/KX_BlenderCanvas.h b/source/gameengine/BlenderRoutines/KX_BlenderCanvas.h
index 817a667d783..6f408f86551 100644
--- a/source/gameengine/BlenderRoutines/KX_BlenderCanvas.h
+++ b/source/gameengine/BlenderRoutines/KX_BlenderCanvas.h
@@ -212,7 +212,6 @@ private:
 	RAS_Rect 	m_area_rect;
 	int			m_area_left;
 	int			m_area_top;
-	int			m_frame;
 
 
 #ifdef WITH_CXX_GUARDEDALLOC