Ability to take snapshots while tracing.

Mostly for purposes of validating the trace/retrace process.

1 files changed, 193 insertions, 0 deletions

diff --git a/glsnapshot.cpp b/glsnapshot.cpp
new file mode 100644
index 0000000..98a11fb
--- /dev/null
+++ b/glsnapshot.cpp
@@ -0,0 +1,193 @@
+/**************************************************************************
+ *
+ * Copyright 2011 Jose Fonseca
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ **************************************************************************/
+
+
+#include <assert.h>
+#include <stdint.h>
+
+#include "image.hpp"
+#include "glproc.hpp"
+#include "glsize.hpp"
+
+
+namespace glsnapshot {
+
+
+/**
+ * Get the contents of the current drawable into an image.
+ */
+static Image::Image *
+getDrawableImage(void) {
+#if defined(_WIN32)
+
+    HDC hDC = __wglGetCurrentDC();
+    if (!hDC) {
+        return false;
+    }
+
+    HWND hWnd = WindowFromDC(hDC);
+    RECT rect;
+
+    if (!GetClientRect(hWnd, &rect)) {
+       return false;
+    }
+
+    int width  = rect.right  - rect.left;
+    int height = rect.bottom - rect.top;
+
+    // TODO: http://msdn.microsoft.com/en-us/library/dd183402
+
+    return NULL;
+
+#elif defined(__APPLE__)
+
+    // TODO
+    return NULL;
+
+#else
+
+    Display *display;
+    Drawable drawable;
+    Window root;
+    int x, y;
+    unsigned int w, h, bw, depth;
+
+    __glFinish();
+    __glXWaitGL();
+
+    display = __glXGetCurrentDisplay();
+    if (!display) {
+        return false;
+    }
+
+    drawable = __glXGetCurrentDrawable();
+    if (drawable == None) {
+        return false;
+    }
+
+    /*
+     * XXX: This does not work for drawables created with glXCreateWindow
+     */
+
+    if (!XGetGeometry(display, drawable, &root, &x, &y, &w, &h, &bw, &depth)) {
+        return false;
+    }
+
+    XImage *ximage;
+
+    ximage = XGetImage(display, drawable, 0, 0, w, h, AllPlanes, ZPixmap);
+    if (!ximage) {
+        return NULL;
+    }
+
+    Image::Image *image = NULL;
+
+    if (ximage->depth          == 24 &&
+        ximage->bits_per_pixel == 32 &&
+        ximage->red_mask       == 0x00ff0000 &&
+        ximage->green_mask     == 0x0000ff00 &&
+        ximage->blue_mask      == 0x000000ff) {
+
+        image = new Image::Image(w, h, 4);
+
+        if (image) {
+            const uint32_t *src = (const uint32_t *)ximage->data;
+            uint32_t *dst = (uint32_t*) image->start();
+            for (int y = 0; y < h; ++y) {
+                for (int x = 0; x < w; ++x) {
+                    uint32_t bgra = src[x];
+                    uint32_t rgba = (bgra & 0xff00ff00)
+                                  | ((bgra >> 16) & 0xff)
+                                  | ((bgra & 0xff) << 16);
+                    dst[x] = rgba;
+                }
+
+                src += ximage->bytes_per_line / sizeof *src;
+                dst += image->stride() / sizeof *src;
+            }
+        }
+    } else {
+        OS::DebugMessage("apitrace: unexpected XImage: "
+                         "bits_per_pixel = %i, "
+                         "depth = %i, "
+                         "red_mask = 0x%08lx, "
+                         "green_mask = 0x%08lx, "
+                         "blue_mask = 0x%08lx\n",
+                         ximage->bits_per_pixel,
+                         ximage->depth,
+                         ximage->red_mask,
+                         ximage->green_mask,
+                         ximage->blue_mask);
+    }
+
+    XDestroyImage(ximage);
+
+    return image;
+#endif
+}
+
+
+// Prefix of the snapshot images to take, if not NULL.
+static const char *snapshot_prefix = NULL;
+
+// Maximum number of frames to trace.
+static unsigned max_frames = ~0;
+
+// Current frame number.
+static unsigned frame_no = 0;
+
+
+void snapshot(unsigned call_no) {
+
+    if (frame_no == 0) {
+        const char *max_frames_str = getenv("TRACE_FRAMES");
+        if (max_frames_str) {
+            max_frames = atoi(max_frames_str);
+        }
+        snapshot_prefix = getenv("TRACE_SNAPSHOT");
+    }
+
+    ++frame_no;
+
+    if (snapshot_prefix) {
+        Image::Image *src = getDrawableImage();
+        if (src) {
+            char filename[PATH_MAX];
+            snprintf(filename, sizeof filename, "%s%010u.png", snapshot_prefix, call_no);
+            if (src->writePNG(filename)) {
+                OS::DebugMessage("apitrace: wrote %s\n", filename);
+            }
+
+            delete src;
+        }
+    }
+
+    if (frame_no >= max_frames) {
+        exit(0);
+    }
+}
+
+
+} /* namespace glsnapshot */