Ticket #7996: screenshot4.diff

scummvm/Makefile

@@ -31 +31 @@
 DEFINES += -DCOMPRESSED_SOUND_FILE
 LIBS    += -lmad
 
+# Uncomment this to activate the PNG lib for screenshots
+# DEFINES += -DHAVE_LIBPNG
+# LIBS    += -lpng
+
 # Uncomment this to activate the ALSA lib for midi
 # DEFINES += -DUSE_ALSA
 # LIBS    += -lasound

scummvm/README

@@ -264 +264 @@
         Ctrl-g                   - runs in really REALLY fast mode.
         Ctrl-d                   - starts the debugger.
         Ctrl-s                   - shows memory consumption.
+        Alt-s                    - save a screenshot
         [ and ]                  - master volume, down/up
         - and +                  - text speed, slower / faster
         F5                       - displays a save/load box.

scummvm/backends/sdl/sdl-common.cpp

@@ -23 +23 @@
 #include "sound/mididrv.h"
 #include "common/scaler.h"
 #include "common/engine.h"      // Only #included for error() and warning()
+#include "common/util.h"
 
 #include "scummvm.xpm"
 
@@ -449 +450 @@
                                         b |= KBD_ALT;
                                 event->kbd.flags = b;
 
+                                // Alt-S makes a screenshot
+                                if (b == KBD_ALT && ev.key.keysym.sym=='s')
+                                        saveScreenshot(this);
+
                                 // Alt-Return toggles full screen mode                          
                                 if (b == KBD_ALT && ev.key.keysym.sym==SDLK_RETURN) {
                                         property(PROP_TOGGLE_FULLSCREEN, NULL);

scummvm/backends/sdl/sdl.cpp

@@ -39 +39 @@
         uint32 property(int param, Property *value);
 
         // Overlay
+        virtual bool is_overlay_visible();
         virtual void show_overlay();
         virtual void hide_overlay();
         virtual void clear_overlay();
@@ -441 +442 @@
         return OSystem_SDL_Common::property(param, value);
 }
 
+bool OSystem_SDL_Normal::is_overlay_visible()
+{
+        return _overlay_visible;
+}
 
 void OSystem_SDL_Normal::show_overlay()
 {

scummvm/common/system.h

@@ -160 +160 @@
         virtual void quit() = 0;
         
         // Overlay
+        virtual bool is_overlay_visible() = 0;
         virtual void show_overlay() = 0;
         virtual void hide_overlay() = 0;
         virtual void clear_overlay() = 0;

scummvm/common/util.cpp

@@ -20 +20 @@
 
 #include "stdafx.h"
 #include "util.h"
+#include "engine.h"     // For debug/warning/error
+
+#ifdef HAVE_LIBPNG
+#include <png.h>
+
+#ifndef png_jmpbuf
+#define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
+#endif
+#endif
 
 //
 // 8-bit alpha blending routines
@@ -157 +166 @@
         }
         return num;
 }
+
+// Global to avoid scary GCC warning
+static FILE *_fp;
+
+void saveScreenshot(OSystem *syst)
+{
+#ifdef HAVE_LIBPNG
+        png_structp png_ptr;
+        png_infop info_ptr;
+        char filename[255];
+        int16 *buf;
+        png_byte *image;
+        int i, j;
+
+        // FIXME: Is there a better way of making a temporary filename? Should
+        // it be made into a separate function?
+
+        for (i = 0; i < 1000; i++) {
+                sprintf(filename, "scr%03d.png", i);
+                _fp = fopen(filename, "rb");
+                if (!_fp)
+                        break;
+        }
+
+        if (_fp) {
+                warning("Could not create temporary filename for screenshot");
+                fclose(_fp);
+                return;
+        }
+
+        _fp = fopen(filename, "wb");
+        if (!_fp) {
+                warning("Could not create temporary file for screenshot");
+                return;
+        }
+
+        // FIXME: We need a way to get the correct screen size. For now, use
+        // the same dirty hack assumptions as newgui.cpp
+
+        int screen_height = 240;
+        int screen_width = 320;
+        int screen_pitch = 320;
+
+        // Apparently it's possible to slim down libpng quite a bit, but I'm
+        // going to assume that all the basic features are still there.
+
+        png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
+                (png_voidp) NULL, (png_error_ptr) NULL, (png_error_ptr) NULL);
+
+        if (!png_ptr) {
+                warning("Could not create PNG write struct");
+                fclose(_fp);
+                return;
+        }
+
+        info_ptr = png_create_info_struct(png_ptr);
+        if (!info_ptr) {
+                warning("Could not create PNG info struct");
+                fclose(_fp);
+                png_destroy_write_struct(&png_ptr, (png_infopp) NULL);
+                return;
+        }
+
+#ifndef PNG_SETJMP_NOT_SUPPORTED
+        if (setjmp(png_jmpbuf(png_ptr))) {
+                warning("Internal libpng error");
+                fclose(_fp);
+                png_destroy_write_struct(&png_ptr, &info_ptr);
+                return;
+        }
+#endif
+
+        png_init_io(png_ptr, _fp);
+
+        buf = (int16 *) malloc(screen_width * screen_height * sizeof(int16));
+        if (!buf) {
+                warning("Could not allocate memory for screen buffer");
+                fclose(_fp);
+                png_destroy_write_struct(&png_ptr, &info_ptr);
+                return;
+        }
+
+        image = (png_byte *) calloc(screen_width, 3 * sizeof(png_byte));
+        if (!image) {
+                warning("Could not allocate memory for PNG image");
+                free(buf);
+                fclose(_fp);
+                png_destroy_write_struct(&png_ptr, &info_ptr);
+                return;
+        }
+
+        // Grab a screenshot
+
+        // FIXME: I'd really like some way of getting the image that is
+        // actually being displayed instead.
+
+        if (!syst->is_overlay_visible()) {
+                syst->show_overlay();
+                syst->grab_overlay(buf, screen_pitch);
+                syst->hide_overlay();
+        } else
+                syst->grab_overlay(buf, screen_pitch);
+
+        png_set_IHDR(png_ptr, info_ptr, screen_width, screen_height, 8,
+                PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
+                PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+
+        png_write_info(png_ptr, info_ptr);
+
+        for (i = 0; i < screen_height; i++) {
+                for (j = 0; j < screen_width; j++) {
+                        image[j * 3 + 0] = RED_FROM_16(buf[i * screen_width + j]);
+                        image[j * 3 + 1] = GREEN_FROM_16(buf[i * screen_width + j]);
+                        image[j * 3 + 2] = BLUE_FROM_16(buf[i * screen_width + j]);
+                }
+
+                png_write_rows(png_ptr, &image, 1);
+        }
+
+        png_write_end(png_ptr, info_ptr);
+        png_destroy_write_struct(&png_ptr, &info_ptr);
+
+        free(buf);
+        free(image);
+        fclose(_fp);
+
+        debug(1, "Saved screenshot as %s", filename);
+#else
+        // FIXME: Should we have a BMP writer as a fallback here?
+        warning("No PNG support! Screenshot feature disabled");
+#endif
+}
+

scummvm/common/util.h

@@ -21 +21 @@
 #ifndef COMMON_UTIL_H
 #define COMMON_UTIL_H
 
+#include "system.h"
 #include "scummsys.h"
 
 #ifndef ABS
@@ -65 +66 @@
 // Resource string length
 int resStrLen(const char *src);
 
+void saveScreenshot(OSystem *system);
+
 #endif