1 TinyLine 2D Overview

1.1 Introduction

TinyLine 2D implements a mobile 2D graphics engine for J2ME platform (CLDC and CDC). TinyLine 2D handles basic shapes, paths, texts, outlined fonts and images in a uniform way. The TinyLine 2D provides access to powerful features such as transparency, path-based drawing, offscreen rendering, advanced color management, antialiased rendering.

Being pure CLDC 1.0 based, TinyLine 2D provides the unified 2D graphics engine for a vast variety of Java platforms and profiles. As a result, developers are easily able to incorporate high quality, scalable and platform-independent graphics into their Java applications across Java profiles from CLDC /MIDP2.0, CDC/Personal Java to J2SE.

1.2 Key features

• Small footprint
• Fast fixed-point numbers mathematics
• Paths, basic shapes and texts drawings
• Hit tests for paths and texts
• Solid color, bitmap, pattern, gradient (radial and linear) paints
• Fill, stroke and dash
• Affine transformations
• Outline fonts
• Left-to-right, right-to-left and vertical text layouts
• Antialiasing
• Opacity

1.3 The TinyLine 2D API

These classes define basic 2D graphics concepts like color, transformation, point, path, etc.

Package com.tinyline.tiny2d

These convenience classes define basic data types, data structures and utilities.

Package com.tinyline.util

1.4 Drawing pipeline

The TinyLine 2D drawing pipeline has four components: Tiny2D, TinyState , TinyBuffer and TinyProducer.

The TinyLine 2D rendering process is controlled through the Tiny2D object and its state attributes. The Tiny2D state attributes, such as line styles and transformations are applied to graphic objects when they are rendered. The collection of state attributes associated with a Tiny2D is referred to as the graphics state TinyState .

The basic drawing process is the same for any graphics element:

1. Specify the target surface TinyBuffer.

2. Specify the appropriate attributes for the graphics by setting the graphics state attributes in the TinyState object.

3. Define the shape or text you want to draw.

3. Use the Tiny2D object to render the shape, paths or text, by calling one of the Tiny2D rendering methods.

During the rasterization, the Tiny2D object reads the graphics state attributes TinyState and applies them to the drawing process of the graphics primitives. The rasterization target is the TinyBuffer object (also named as "canvas") where all is drawn. When the drawing process has completed the TinyProducer is notified that new pixels on the TinyBuffer "canvas" are ready to be send onto a device screen.

1.5 The painters model

TinyLine 2D uses the painter's model for its imaging. In the painter's model, each successive drawing operation applies a layer of "paint" to an output "canvas" - TinyBuffer object. The paint on the pixels buffer (TinyBuffer object) can be modified by overlaying more paint through additional drawing operations. This model allows you to construct sophisticated images from a small number of primitives.

When the paint is not completely opaque the result on the pixels buffer is defined by the (mathematical) rules of the simple alpha blending.

1.6 Coordinate spaces

TinyLine 2D supports three coordinate spaces: character space, user space and device space. Transformations between coordinate spaces are defined by transformation matrices, which can specify any linear mapping of two-dimensional coordinates.

1.7 Graphics elements

TinyLine 2D supports two basic types of graphics elements that can be rendered onto the TinyBuffer object:

• Shapes, which represent some combination of straight line and curves
• Text, which represents some combination of character glyphs

As about raster images, a raster image is presented via the TinyColor class as array of values that specify the paint color and opacity (alpha).

Shapes and text can be filled and stroked. Each fill and stroke operation has its own opacity settings; thus, you can fill and/or stroke a shape with a semi-transparently drawn solid color, with different opacity values for the fill and stroke operations.

1.8 Text and fonts

In TinyLine 2D texts are rendered just like shapes. Therefore, coordinate system transformations, painting - all TinyState graphics state attributes apply to text in the same way as they apply to shapes or paths.

Additional text attributes include such things like the writing direction (text layout), font specification (TinyFont) and painting attributes which describe how exactly to render the characters.

The TinyFont class includes the information necessary to map characters to glyphs, to determine the size of glyph areas and to position the glyph area.

1.9 Colors

TinyLine 2D supports the following built-in types of paint that can be used in fill and stroke operations using the ARGB color space:

• Single color
• Gradients (linear and radial)
• Patterns (raster images)

1.10 TinyLine 2D Examples

TinyLine 2D comes with the following examples: