NPAPI:DrawImage: Difference between revisions

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NPAPI:DrawImage (view source)

Revision as of 14:48, 12 May 2010

937 bytes added , 12 May 2010

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Romaxa

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@@ Line 5: / Line 5: @@
 = Contributors =
-* Last modified: April 27, 2010
+* Last modified: May 12, 2010
 * Authors: Oleg Romashin (Nokia), Josh Aas (Mozilla)
-* Contributors:
+* Contributors: Robert O'Callahan (Mozilla)
 = Overview =
@@ Line 38: / Line 38: @@
    typedef enum {
-     NPImageFormatARGB32     = 0,  /* a8r8g8b8 */
+     /* each pixel is a 32-bit quantity, with
-     NPImageFormatRGB24      = 2,  /* x8r8g8b8 */
+     * alpha in the upper 8 bits, then red, then green, then blue.
-     NPImageFormatRGB16_565  = 3   /* r5g6b5   */
+     * The 32-bit quantities are stored native-endian. Pre-multiplied
-     ...
+     * alpha is used. (That is, 50% transparent red is 0x80800000,
+     * not 0x80ff0000.) */
+     NPImageFormatARGB32_pre = 0x1,
+    /* each pixel is a 32-bit quantity, with
+     * the upper 8 bits unused. Red, Green, and Blue are stored
+     * in the remaining 24 bits in that order. */
+     NPImageFormatRGB24      = 0x2,  /* x8r8g8b8 */
+     NPImageFormatRGB16_565  = 0x4   /* r5g6b5   */
+     /* non-premultiplied version of RGBA32 format */
+    NPImageFormatARGB32     = 0x8,
+    /* can be extended */
    } NPImageFormat;
@@ Line 50: / Line 60: @@
      int32_t       stride;     /* Stride of data image pointer */
      NPImageFormat format;     /* Format of image pointer */
-     NPSize        dataSize;   /* Data buffer size */
+     /* size of plugin window in current buffer, used for scale information */
-    /* Clip rectangle, must be used for trusted plugins */
+     NPSize        pluginSize;
-     int32_t       x;      /* Expose x relative to 0,0 of plugin window area*/
+    /* "data" points to exposeX/Y point, which is also offset in plugin window area */
-     int32_t       y;      /* Expose y relative to 0,0 of plugin window area */
+     int32_t       exposeX;
-     uint32_t      width;  /* Expose width */
+     int32_t       exposeY;
-     uint32_t      height; /* Expose height */
+     /* size of data buffer, size of area where plugin should paint */
-    /* Position and scale values for plugin area */
+     /* exposeX/Y + exposeSize <= pluginSize */
-     float         translateX; /* translate X matrix value, (x offset) */
+     NPSize        exposeSize;
-    float         translateY; /* translate Y matrix value, (y offset) */
-    /* Defines plugin window size on scaled context, if 1 then size = window size */
-     float         scaleX;     /* scale X matrix value */
-    float         scaleY;     /* scale Y matrix value */
    } NPImageData;
+How to initialize cairo destination surface with this info:
+<pre>
+cairo_surface_t *src = plugin_window_image (probably cached)
+cairo_surface_t *dest =
+  cairo_image_surface_create_for_data((unsigned char*)event->data,
+                                      CAIRO_FORMAT_XXX(event->format),
+                                      event->exposeSize.width,
+                                      event->exposeSize.height,
+                                      event->stride);
+cairo_t *cr = cairo_create(dest);
+cairo_set_source_surface (cr, src, -event->exposeRect.left, -event->exposeRect.top);
+</pre>
 = NPImageFormat Type Negotiation =
-* NPNVSupportedImageFormats (NPNVariable = ?)
+* NPNVsupportedImageFormats (NPNVariable = 19)
-* NPPVImageFormat (NPPVariable = ?)
+* NPPVImageFormats (NPPVariable = 22)
-Negotiating the image format will work similarly to [[NPAPI:Models|drawing and event model negotiation]], but the value of NPNVsupportsImageFormat will be a bitmap of supported types. Based on the browser's supported formats, the plugin should select a format.
+Negotiating the image format will work similarly to [[NPAPI:Models|drawing and event model negotiation]], but the value of NPNVsupportedImageFormats will be a bitmap of supported types. Based on the browser's supported formats, the plugin should select a subset which it can handle. The format for any given event will be specified in the event, and will be from the plugin's supported subset.
    NPImageFormat supportedFormats;
-   browserFuncs->getvalue(instance, NPNVsupportsImageFormat, &supportedFormats);
+   browserFuncs->getvalue(instance, NPNVsupportedImageFormats, &supportedFormats);
    ...
-   browserFuncs->setvalue(instance, NPPVImageFormat, (void*)selectedFormat);
+   browserFuncs->setvalue(instance, NPPVImageFormats, (void*)supportedSubset);