emu_view_tile.c File Reference

Pure bounded tile rotation plus checked raw-surface row writes. More...

#include "emu_view.h"
#include "emu_view_tile_internal.h"

Include dependency graph for emu_view_tile.c:

Go to the source code of this file.

Data Structures
struct	tile_destination_t
	Rotated tile placement and dimensions. More...

Functions
static RA8_INTERNAL size_t	internal_row_offset (const emu_presentation_workspace_t *presentation, uint16_t x, uint16_t y)
	Return the raw-surface byte offset of one display row.
static RA8_INTERNAL bool	internal_write_rows (emu_presentation_workspace_t *presentation, const uint16_t *pixels, const tile_destination_t *destination)
	Write one contiguous tile into checked raw-surface rows.
static RA8_INTERNAL tile_destination_t	internal_tile_destination (const emu_presentation_workspace_t *presentation, uint16_t source_x, uint16_t source_y, uint16_t width, uint16_t height)
	Resolve one source tile's placement after panel rotation.
static RA8_INTERNAL void	internal_rotate_tile (const emu_presentation_workspace_t *presentation, const uint16_t *source, uint16_t *rotated, uint16_t width, uint16_t height, uint16_t output_width)
	Rotate one bounded RGB565 tile into caller scratch.
bool	priv_emu_view_tile_write (emu_presentation_workspace_t *presentation, const uint16_t *source, uint16_t source_x, uint16_t source_y, uint16_t width, uint16_t height)
	Rotate and write one native-panel tile into its exact display location.

Detailed Description

Pure bounded tile rotation plus checked raw-surface row writes.

Maps native panel coordinates through each supported display rotation and writes exact RGB565 row spans into the descriptor-backed composite while rejecting overflow and out-of-range placements.

Copyright

Copyright (c) 2026 Brighton Sikarskie SPDX-License-Identifier: MIT

Since

0.1.0

Definition in file emu_view_tile.c.

Function Documentation

internal_rotate_tile()

RA8_INTERNAL void internal_rotate_tile ( const emu_presentation_workspace_t * presentation, const uint16_t * source, uint16_t * rotated, uint16_t width, uint16_t height, uint16_t output_width )

static

Rotate one bounded RGB565 tile into caller scratch.

Rotate one bounded rgb565 tile into caller scratch; this step is contained within the emu view tile model and uses bounded caller or module-owned storage.

Parameters

[in]	presentation	Descriptor-backed presentation workspace accessed by the operation.
[in]	source	Source input used by the operation.
[in,out]	rotated	Rotated state or storage updated in place by the operation.
[in]	width	Width of the affected region in pixels.
[in]	height	Height of the affected region in pixels.
[in]	output_width	Output width input used by the operation.

Precondition

Arguments satisfy the ranges documented for rotate tile.

The call executes on the emulator's single owning thread.

Postcondition

State changes remain confined to the emu view tile model and documented output objects.

Ownership of caller-supplied storage is unchanged.

Note

The operation is synchronous and does not transfer heap ownership.

Since

0.1.0

Definition at line 127 of file emu_view_tile.c.

References k_rotate_180, k_rotate_90, RA8_INTERNAL, and emu_presentation_workspace_t::rotate_deg.

Referenced by priv_emu_view_tile_write().

internal_row_offset()

RA8_INTERNAL size_t internal_row_offset ( const emu_presentation_workspace_t * presentation, uint16_t x, uint16_t y )

static

Return the raw-surface byte offset of one display row.

Return the raw-surface byte offset of one display row; this step is contained within the emu view tile model and uses bounded caller or module-owned storage.

Parameters

[in]	presentation	Descriptor-backed presentation workspace accessed by the operation.
[in]	x	Horizontal coordinate in pixels.
[in]	y	Vertical coordinate in pixels.

Returns

The row offset result produced by the emu view tile model.

Return values

value

The operation-specific row offset value.

Precondition

Arguments satisfy the ranges documented for row offset.

The call executes on the emulator's single owning thread.

Postcondition

State changes remain confined to the emu view tile model and documented output objects.

Ownership of caller-supplied storage is unchanged.

Note

The operation is synchronous and does not transfer heap ownership.

Since

0.1.0

Definition at line 30 of file emu_view_tile.c.

References emu_presentation_workspace_t::composite_width.

Referenced by internal_write_rows().

internal_tile_destination()

RA8_INTERNAL tile_destination_t internal_tile_destination ( const emu_presentation_workspace_t * presentation, uint16_t source_x, uint16_t source_y, uint16_t width, uint16_t height )

static

Resolve one source tile's placement after panel rotation.

Resolve one source tile's placement after panel rotation; this step is contained within the emu view tile model and uses bounded caller or module-owned storage.

Parameters

[in]	presentation	Descriptor-backed presentation workspace accessed by the operation.
[in]	source_x	Source x input used by the operation.
[in]	source_y	Source y input used by the operation.
[in]	width	Width of the affected region in pixels.
[in]	height	Height of the affected region in pixels.

Returns

The tile destination result produced by the emu view tile model.

Return values

value

The operation-specific tile destination value.

Precondition

Arguments satisfy the ranges documented for tile destination.

The call executes on the emulator's single owning thread.

Postcondition

State changes remain confined to the emu view tile model and documented output objects.

Ownership of caller-supplied storage is unchanged.

Note

The operation is synchronous and does not transfer heap ownership.

Since

0.1.0

Definition at line 88 of file emu_view_tile.c.

References tile_destination_t::height, k_rotate_180, k_rotate_270, k_rotate_90, emu_presentation_workspace_t::panel_height, emu_presentation_workspace_t::panel_width, emu_presentation_workspace_t::rotate_deg, tile_destination_t::width, tile_destination_t::x, and tile_destination_t::y.

Referenced by priv_emu_view_tile_write().

internal_write_rows()

RA8_INTERNAL bool internal_write_rows ( emu_presentation_workspace_t * presentation, const uint16_t * pixels, const tile_destination_t * destination )

static

Write one contiguous tile into checked raw-surface rows.

Write one contiguous tile into checked raw-surface rows; this step is contained within the emu view tile model and uses bounded caller or module-owned storage.

Parameters

[in,out]	presentation	Descriptor-backed presentation workspace accessed by the operation.
[in]	pixels	Pixels input used by the operation.
[in]	destination	Destination input used by the operation.

Returns

The write rows result produced by the emu view tile model.

Return values

true	The write rows condition holds or completed successfully; false otherwise.

Precondition

Arguments satisfy the ranges documented for write rows.

The call executes on the emulator's single owning thread.

Postcondition

State changes remain confined to the emu view tile model and documented output objects.

Ownership of caller-supplied storage is unchanged.

Note

The operation is synchronous and does not transfer heap ownership.

Since

0.1.0

Definition at line 56 of file emu_view_tile.c.

References emu_presentation_write(), tile_destination_t::height, internal_row_offset(), RA8_INTERNAL, tile_destination_t::width, tile_destination_t::x, and tile_destination_t::y.

Referenced by priv_emu_view_tile_write().

priv_emu_view_tile_write()

bool priv_emu_view_tile_write	(	emu_presentation_workspace_t *	presentation,
		const uint16_t *	source,
		uint16_t	source_x,
		uint16_t	source_y,
		uint16_t	width,
		uint16_t	height )

Rotate and write one native-panel tile into its exact display location.

Rotate and write one native-panel tile into its exact display location; this step is contained within the emu view tile model and uses bounded caller or module-owned storage.

Parameters

[in,out]	presentation	Descriptor-backed presentation workspace accessed by the operation.
[in]	source	Source input used by the operation.
[in]	source_x	Source x input used by the operation.
[in]	source_y	Source y input used by the operation.
[in]	width	Width of the affected region in pixels.
[in]	height	Height of the affected region in pixels.

Returns

The emu view tile write result produced by the emu view tile model.

Return values

true	The emu view tile write condition holds or completed successfully; false otherwise.

Precondition

Arguments satisfy the ranges documented for emu view tile write.

The call executes on the emulator's single owning thread.

Postcondition

State changes remain confined to the emu view tile model and documented output objects.

Ownership of caller-supplied storage is unchanged.

Note

The operation is synchronous and does not transfer heap ownership.

Since

0.1.0

Definition at line 154 of file emu_view_tile.c.

References internal_rotate_tile(), internal_tile_destination(), internal_write_rows(), k_emu_presentation_tile_px, emu_presentation_workspace_t::panel_height, emu_presentation_workspace_t::panel_width, emu_presentation_workspace_t::rotate_deg, emu_presentation_workspace_t::scratch, and tile_destination_t::width.

Referenced by internal_write_layer().