/// <summary>Construct a canvas with the specified bitmap to draw into.</summary> /// <remarks> /// Construct a canvas with the specified bitmap to draw into. The bitmap /// must be mutable. /// <p>The initial target density of the canvas is the same as the given /// bitmap's density. /// </remarks> /// <param name="bitmap">Specifies a mutable bitmap for the canvas to draw into.</param> public Canvas(android.graphics.Bitmap bitmap) { if (!bitmap.isMutable()) { throw new System.InvalidOperationException("Immutable bitmap passed to Canvas constructor" ); } throwIfRecycled(bitmap); mNativeCanvas = initRaster(bitmap.nativeInstance); mBitmap = bitmap; mDensity = bitmap.mDensity; }
/// <summary> /// Returns an immutable bitmap from subset of the source bitmap, /// transformed by the optional matrix. /// </summary> /// <remarks> /// Returns an immutable bitmap from subset of the source bitmap, /// transformed by the optional matrix. It is /// initialized with the same density as the original bitmap. /// </remarks> /// <param name="source">The bitmap we are subsetting</param> /// <param name="x">The x coordinate of the first pixel in source</param> /// <param name="y">The y coordinate of the first pixel in source</param> /// <param name="width">The number of pixels in each row</param> /// <param name="height">The number of rows</param> /// <param name="m">Optional matrix to be applied to the pixels</param> /// <param name="filter"> /// true if the source should be filtered. /// Only applies if the matrix contains more than just /// translation. /// </param> /// <returns>A bitmap that represents the specified subset of source</returns> /// <exception cref="System.ArgumentException"> /// if the x, y, width, height values are /// outside of the dimensions of the source bitmap. /// </exception> public static android.graphics.Bitmap createBitmap(android.graphics.Bitmap source , int x, int y, int width, int height, android.graphics.Matrix m, bool filter) { checkXYSign(x, y); checkWidthHeight(width, height); if (x + width > source.getWidth()) { throw new System.ArgumentException("x + width must be <= bitmap.width()"); } if (y + height > source.getHeight()) { throw new System.ArgumentException("y + height must be <= bitmap.height()"); } // check if we can just return our argument unchanged if (!source.isMutable() && x == 0 && y == 0 && width == source.getWidth() && height == source.getHeight() && (m == null || m.isIdentity())) { return source; } int neww = width; int newh = height; android.graphics.Canvas canvas = new android.graphics.Canvas(); android.graphics.Bitmap bitmap; android.graphics.Paint paint; android.graphics.Rect srcR = new android.graphics.Rect(x, y, x + width, y + height ); android.graphics.RectF dstR = new android.graphics.RectF(0, 0, width, height); android.graphics.Bitmap.Config newConfig = android.graphics.Bitmap.Config.ARGB_8888; android.graphics.Bitmap.Config config = source.getConfig(); // GIF files generate null configs, assume ARGB_8888 if (config != null) { switch (config) { case android.graphics.Bitmap.Config.RGB_565: { newConfig = android.graphics.Bitmap.Config.RGB_565; break; } case android.graphics.Bitmap.Config.ALPHA_8: { newConfig = android.graphics.Bitmap.Config.ALPHA_8; break; } case android.graphics.Bitmap.Config.ARGB_4444: case android.graphics.Bitmap.Config.ARGB_8888: default: { //noinspection deprecation newConfig = android.graphics.Bitmap.Config.ARGB_8888; break; } } } if (m == null || m.isIdentity()) { bitmap = createBitmap(neww, newh, newConfig, source.hasAlpha()); paint = null; } else { // not needed bool transformed = !m.rectStaysRect(); android.graphics.RectF deviceR = new android.graphics.RectF(); m.mapRect(deviceR, dstR); neww = Sharpen.Util.Round(deviceR.width()); newh = Sharpen.Util.Round(deviceR.height()); bitmap = createBitmap(neww, newh, transformed ? android.graphics.Bitmap.Config.ARGB_8888 : newConfig, transformed || source.hasAlpha()); canvas.translate(-deviceR.left, -deviceR.top); canvas.concat(m); paint = new android.graphics.Paint(); paint.setFilterBitmap(filter); if (transformed) { paint.setAntiAlias(true); } } // The new bitmap was created from a known bitmap source so assume that // they use the same density bitmap.mDensity = source.mDensity; canvas.setBitmap(bitmap); canvas.drawBitmap(source, srcR, dstR, paint); canvas.setBitmap(null); return bitmap; }
/// <summary>Specify a bitmap for the canvas to draw into.</summary> /// <remarks> /// Specify a bitmap for the canvas to draw into. As a side-effect, also /// updates the canvas's target density to match that of the bitmap. /// </remarks> /// <param name="bitmap">Specifies a mutable bitmap for the canvas to draw into.</param> /// <seealso cref="setDensity(int)">setDensity(int)</seealso> /// <seealso cref="getDensity()">getDensity()</seealso> public virtual void setBitmap(android.graphics.Bitmap bitmap) { if (isHardwareAccelerated()) { throw new java.lang.RuntimeException("Can't set a bitmap device on a GL canvas"); } android.graphics.Bitmap.NativeBitmap pointer = null; if (bitmap != null) { if (!bitmap.isMutable()) { throw new System.InvalidOperationException(); } throwIfRecycled(bitmap); mDensity = bitmap.mDensity; pointer = bitmap.nativeInstance; } native_setBitmap(mNativeCanvas, pointer); mBitmap = bitmap; }