Kanzi编程基础3 - 图片读取与显示

时间：2021-01-16 20:55:24

Kanzi开发的时候会遇到需要从外部读取图片的情况。Kanzi2.8版本和3.3版本读取方法稍有不同，我们先看看2.8版本的api。

【2.8版本】

1）首先要从文件中读取一张图片

struct KzcImage* img;

kzcImageLoadFile(kzaApplicationGetSystemMemoryManager(application),"1.png",& img);

2）把文件中读取到的图片转成Texture

KzuImageTexture* texture;

kzuImageTextureCreateFromImage(resMgr, "FileTexture",

                   img, KZU_TEXTURE_FILTER_BILINEAR, KZU_TEXTURE_WRAP_CLAMP, 0.0f, &texture);

或者从内存数据中创建一个Texture：

kzuImageTextureCreateFromMemory(resourceManger,name,

                                        KZU_TEXTURE_CHANNELS_RGB,

                                        img.width(), img.height(), img.bits(),

                                        KZU_TEXTURE_FILTER_BILINEAR, KZU_TEXTURE_WRAP_CLAMP, &imageTexture);

其中resourceManger是一个ResourceManger对象，name为Texture的名称，KZU_TEXTURE_CHANNELS_RGB为创建的图像模式，bits（）为图片数据，最终创建到imageTexture中。

3）创建之后转成resource并赋给plane节点

struct KzuResource* out_resource;

out_resource = kzuImageTextureToResource(texture);

kzuObjectNodeSetResourceIDResourceProperty(planeNode,KZU_PROPERTY_TYPE_TEXTURE,out_resource);

kzuObjectNodeSetIntProperty(m_planeNode, KZU_PROPERTY_TYPE_BLEND_MODE, );

kzuResourceRelease(out_resource);

【3.3版本】

3.3可以参考kanzi安装目录下的 virtual listbox的例子。

下面是例子中的关键代码：

 if (m_itemInfo->m_objectNode && m_image)

 {

 Domain* domain = m_itemGenerator->m_listBox->getDomain();

 // Create texture from image. If the image data format is correct, this shouldn't use any memory manager.

 // Image texture will own the image so no need to delete it manually.

 TextureSharedPtr texture = Texture::create(domain, m_image, Texture::CreateFlagClampAddress);

 m_itemInfo->m_objectNode->setProperty(StandardMaterial::TextureProperty, texture);

 // Adjust size of plane for displaying the image.

 Node3DSharedPtr imagePlaneNode = m_itemInfo->m_objectNode->lookupNode<Node3D>("Stack Layout/Plane");

 kzUint height = kzcImageGetHeight(m_image);

 kzUint width = kzcImageGetWidth(m_image);

 float aspect = width * 1.0f / height;

 kzFloat widthFactor = aspect;

 kzFloat heightFactor = 1.0f;

 if(aspect > 1.0f)

 {

 widthFactor = 1.0f;

 heightFactor = 1.0f / aspect;

 }

 imagePlaneNode->setLayoutTransformation(Matrix4x4::createScale(Vector3(widthFactor, heightFactor, 1.0f)));

 // Ownership of image was transferred to the texture.

 m_image = ;

 }

 // Remove task.

 m_itemGenerator->m_tasksByItems.erase(m_itemInfo);

3.3版本的代码暂时还没有分析，待补充……

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