Package eu.svjatoslav.sixth.e3d.gui

Class RenderingContext

java.lang.Object
eu.svjatoslav.sixth.e3d.gui.RenderingContext
Direct Known Subclasses:
SegmentRenderingContext
public class RenderingContext extends Object
Contains all state needed to render a single frame: the pixel buffer, graphics context, screen dimensions, and mouse event tracking.

A new RenderingContext is created whenever the view panel is resized. During rendering, shapes use this context to:

The context also manages mouse interaction detection: as shapes are painted back-to-front, each shape can report itself as the object under the mouse cursor. After painting completes, the topmost shape receives the mouse event.

See Also:

  • Field Details

    • bufferedImageType

      public static final int bufferedImageType
      The BufferedImage pixel format used for the rendering buffer. TYPE_INT_RGB provides optimal performance for Java2D blitting.
      See Also:

    • NUM_RENDER_SEGMENTS

      public static final int NUM_RENDER_SEGMENTS
      Number of horizontal segments for parallel rendering. Each segment is rendered by a separate thread.
      See Also:

    • graphics

      public final Graphics2D graphics
      Java2D graphics context for drawing text, anti-aliased shapes, and other high-level graphics operations onto the render buffer.

    • pixels

      public final int[] pixels
      Pixels of the rendering area. Each pixel is a single int in RGB format: (r << 16) | (g << 8) | b.

    • width

      public final int width
      Width of the rendering area in pixels.

    • height

      public final int height
      Height of the rendering area in pixels.

    • centerCoordinate

      public final Point2D centerCoordinate
      Center of the screen in screen space (pixels). This is the point where (0,0) coordinate of the world space is rendered.

    • projectionScale

      public final double projectionScale
      Scale factor for perspective projection, derived from screen width. Used to convert normalized device coordinates to screen pixels.

    • renderMinY

      public final int renderMinY
      Minimum Y coordinate (inclusive) to render. Used for multi-threaded rendering where each thread renders a horizontal segment.

    • renderMaxY

      public final int renderMaxY
      Maximum Y coordinate (exclusive) to render. Used for multi-threaded rendering where each thread renders a horizontal segment.

    • frameNumber

      public int frameNumber
      Number of frame that is currently being rendered. Every frame has its own number.

    • developerTools

      public DeveloperTools developerTools
      Developer tools for this rendering context. Controls diagnostic features like logging and visualization.

    • debugLogBuffer

      public DebugLogBuffer debugLogBuffer
      Debug log buffer for capturing diagnostic output. Shapes can log messages here that appear in the Developer Tools panel.

    • lightingManager

      public LightingManager lightingManager
      Global lighting manager for the scene. All shaded polygons use this to calculate lighting. Contains all light sources and ambient light settings for the world.

    • frustum

      public Frustum frustum
      View frustum for frustum culling. Updated each frame from camera state and screen dimensions. Shapes can test their bounding boxes against this frustum to determine if they are potentially visible before expensive vertex transformations.

    • cullingStatistics

      public CullingStatistics cullingStatistics
      Statistics for frustum culling performance tracking. Updated each frame: total shapes counted at start, visible shapes incremented during rendering, culled composites tracked during transform.

  • Constructor Details

    • RenderingContext

      public RenderingContext(int width, int height)
      Creates a new rendering context for full-screen rendering.

      Equivalent to RenderingContext(width, height, 0, height).

      Parameters:
      width - the rendering area width in pixels
      height - the rendering area height in pixels

    • RenderingContext

      public RenderingContext(int width, int height, int renderMinY, int renderMaxY)
      Creates a new rendering context with Y-bounds for segment rendering.

      Initializes the offscreen image buffer, extracts the raw pixel byte array, and configures anti-aliasing on the Graphics2D context.

      Parameters:
      width - the rendering area width in pixels
      height - the rendering area height in pixels
      renderMinY - minimum Y coordinate (inclusive) to render
      renderMaxY - maximum Y coordinate (exclusive) to render

    • RenderingContext

      protected RenderingContext(RenderingContext parent, int renderMinY, int renderMaxY)
      Protected constructor for creating segment views. Shares the pixel buffer and graphics context with the parent.
      Parameters:
      parent - the parent rendering context
      renderMinY - minimum Y coordinate (inclusive) for this segment
      renderMaxY - maximum Y coordinate (exclusive) for this segment

  • Method Details

    • prepareForNewFrameRendering

      public void prepareForNewFrameRendering()
      Resets per-frame state in preparation for rendering a new frame. Increments the frame number and clears the mouse event state.

    • getSegmentGraphics

      public Graphics2D getSegmentGraphics(int segmentIndex)
      Returns the Graphics2D context for a specific render segment. Each segment's Graphics2D is pre-clipped to its Y bounds.
      Parameters:
      segmentIndex - the segment index (0 to NUM_RENDER_SEGMENTS-1)
      Returns:
      the Graphics2D for that segment
      Throws:
      NullPointerException - if called on a segment view (not the main context)

    • dispose

      public void dispose()
      Disposes all Graphics2D resources associated with this context. Should be called when the context is no longer needed (e.g., on resize).

    • executeWithGraphics

      public void executeWithGraphics(Consumer<Graphics2D> operation)
      Executes a graphics operation in a thread-safe manner. This must be used for all Graphics2D operations (text, lines, etc.) during multi-threaded rendering.
      Parameters:
      operation - the graphics operation to execute

    • getMouseEvent

      public MouseEvent getMouseEvent()
      Returns the pending mouse event for this frame, or null if none.
      Returns:
      the mouse event to process, or null

    • setMouseEvent

      public void setMouseEvent(MouseEvent mouseEvent)
      Sets the mouse event to be processed during this frame's rendering.
      Parameters:
      mouseEvent - the mouse event with position and button information

    • setCurrentObjectUnderMouseCursor

      public void setCurrentObjectUnderMouseCursor(MouseInteractionController currentObjectUnderMouseCursor)
      Called when given object was detected under mouse cursor, while processing mouseEvent. Because objects are rendered back to front. The last method caller will set the top-most object, if there are multiple objects under mouse cursor.
      Parameters:
      currentObjectUnderMouseCursor - the object that is currently under the mouse cursor

    • getCurrentObjectUnderMouseCursor

      public MouseInteractionController getCurrentObjectUnderMouseCursor()
      Returns the current object under the mouse cursor. Used by segment rendering to collect mouse results.
      Returns:
      the current object under mouse cursor, or null

    • handlePossibleComponentMouseEvent

      public boolean handlePossibleComponentMouseEvent()
      Handles mouse events for components and returns whether a view repaint is needed.
      Returns:
      true if view update is needed as a consequence of this mouse event