/* Copyright (c) 2012 The Chromium Authors. All rights reserved. * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ /** * This file defines the <code>PPB_ImageData</code> struct for determining how * a browser handles image data. */ [generate_thunk] label Chrome { M14 = 1.0 }; /** * <code>PP_ImageDataFormat</code> is an enumeration of the different types of * image data formats. * * The third part of each enumeration value describes the memory layout from * the lowest address to the highest. For example, BGRA means the B component * is stored in the lowest address, no matter what endianness the platform is * using. * * The PREMUL suffix implies pre-multiplied alpha is used. In this mode, the * red, green and blue color components of the pixel data supplied to an image * data should be pre-multiplied by their alpha value. For example: starting * with floating point color components, here is how to convert them to 8-bit * premultiplied components for image data: * * ...components of a pixel, floats ranging from 0 to 1... * <code>float red = 1.0f;</code> * <code>float green = 0.50f;</code> * <code>float blue = 0.0f;</code> * <code>float alpha = 0.75f;</code> * ...components for image data are 8-bit values ranging from 0 to 255... * <code>uint8_t image_data_red_premul = (uint8_t)(red * alpha * 255.0f); * </code> * <code>uint8_t image_data_green_premul = (uint8_t)(green * alpha * 255.0f); * </code> * <code>uint8_t image_data_blue_premul = (uint8_t)(blue * alpha * 255.0f); * </code> * <code>uint8_t image_data_alpha_premul = (uint8_t)(alpha * 255.0f);</code> * * <strong>Note:</strong> The resulting pre-multiplied red, green and blue * components should not be greater than the alpha value. */ [assert_size(4)] enum PP_ImageDataFormat { PP_IMAGEDATAFORMAT_BGRA_PREMUL, PP_IMAGEDATAFORMAT_RGBA_PREMUL }; /** * The <code>PP_ImageDataDesc</code> structure represents a description of * image data. */ [assert_size(16)] struct PP_ImageDataDesc { /** * This value represents one of the image data types in the * <code>PP_ImageDataFormat</code> enum. */ PP_ImageDataFormat format; /** This value represents the size of the bitmap in pixels. */ PP_Size size; /** * This value represents the row width in bytes. This may be different than * width * 4 since there may be padding at the end of the lines. */ int32_t stride; }; /** * The <code>PPB_ImageData</code> interface contains pointers to several * functions for determining the browser's treatment of image data. */ interface PPB_ImageData { /** * GetNativeImageDataFormat() returns the browser's preferred format for * image data. The browser uses this format internally for painting. Other * formats may require internal conversions to paint or may have additional * restrictions depending on the function. * * @return A <code>PP_ImageDataFormat</code> containing the preferred format. */ PP_ImageDataFormat GetNativeImageDataFormat(); /** * IsImageDataFormatSupported() determines if the given image data format is * supported by the browser. Note: <code>PP_IMAGEDATAFORMAT_BGRA_PREMUL</code> * and <code>PP_IMAGEDATAFORMAT_RGBA_PREMUL</code> formats are always * supported. Other image formats do not make this guarantee, and should be * checked first with IsImageDataFormatSupported() before using. * * @param[in] format The image data format. * * @return A <code>PP_Bool</code> with <code>PP_TRUE</code> if the given * image data format is supported by the browser. */ PP_Bool IsImageDataFormatSupported( [in] PP_ImageDataFormat format); /** * Create() allocates an image data resource with the given format and size. * * For security reasons, if uninitialized, the bitmap will not contain random * memory, but may contain data from a previous image produced by the same * module if the bitmap was cached and re-used. * * @param[in] instance A <code>PP_Instance</code> identifying one instance * of a module. * @param[in] format The desired image data format. * @param[in] size A pointer to a <code>PP_Size</code> containing the image * size. * @param[in] init_to_zero A <code>PP_Bool</code> to determine transparency * at creation. * Set the <code>init_to_zero</code> flag if you want the bitmap initialized * to transparent during the creation process. If this flag is not set, the * current contents of the bitmap will be undefined, and the module should * be sure to set all the pixels. * * @return A <code>PP_Resource</code> with a nonzero ID on success or zero on * failure. Failure means the instance, image size, or format was invalid. */ PP_Resource Create( [in] PP_Instance instance, [in] PP_ImageDataFormat format, [in] PP_Size size, [in] PP_Bool init_to_zero); /** * IsImageData() determines if a given resource is image data. * * @param[in] image_data A <code>PP_Resource</code> corresponding to image * data. * * @return A <code>PP_Bool</code> with <code>PP_TRUE</code> if the given * resource is an image data or <code>PP_FALSE</code> if the resource is * invalid or some type other than image data. */ PP_Bool IsImageData( [in] PP_Resource image_data); /** * Describe() computes the description of the * image data. * * @param[in] image_data A <code>PP_Resource</code> corresponding to image * data. * @param[in,out] desc A pointer to a <code>PP_ImageDataDesc</code> * containing the description. * * @return A <code>PP_Bool</code> with <code>PP_TRUE</code> on success or * <code>PP_FALSE</code> if the resource is not an image data. On * <code>PP_FALSE</code>, the <code>desc</code> structure will be filled * with 0. */ [always_set_output_parameters] PP_Bool Describe( [in] PP_Resource image_data, [out] PP_ImageDataDesc desc); /** * Map() maps an image data into the module address space. * * @param[in] image_data A <code>PP_Resource</code> corresponding to image * data. * * @return A pointer to the beginning of the data. */ mem_t Map( [in] PP_Resource image_data); /** * Unmap is a pointer to a function that unmaps an image data from the module * address space. * * @param[in] image_data A <code>PP_Resource</code> corresponding to image * data. */ void Unmap( [in] PP_Resource image_data); };