102 lines
3.5 KiB
C
102 lines
3.5 KiB
C
//---
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// gint:image - Image manipulation
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//
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// Note: this module is currently only available on fx-CG.
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//
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// This module supports 3 bit depths: full-color 16-bit (RGB565), indexed 8-bit
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// (P8) and indexed 4-bit (P4). All three have an "alpha" variation where one
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// color is treated as transparent, leading to 6 total formats.
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//---
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#ifndef GINT_IMAGE
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#define GINT_IMAGE
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#include <stdint.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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//---
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// Image structures
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//---
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/* Image formats. Note that transparency really only indicates the default
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rendering method, as a transparent background can always be added or removed
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by a dynamic effect on any image. */
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enum {
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IMAGE_RGB565 = 0, /* RGB565 without alpha */
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IMAGE_RGB565A = 1, /* RGB565 with one transparent color */
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IMAGE_P8_RGB565 = 4, /* 8-bit palette, all opaque colors */
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IMAGE_P8_RGB565A = 5, /* 8-bit with one transparent color */
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IMAGE_P4_RGB565 = 6, /* 4-bit palette, all opaque colors */
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IMAGE_P4_RGB565A = 3, /* 4-bit with one transparent color */
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IMAGE_DEPRECATED_P8 = 2,
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};
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/* Quick macros to compare formats by storage size */
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#define IMAGE_IS_RGB16(format) \
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((format) == IMAGE_RGB565 || (format) == IMAGE_RGB565A)
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#define IMAGE_IS_P8(format) \
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((format) == IMAGE_P8_RGB565 || (format) == IMAGE_P8_RGB565A)
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#define IMAGE_IS_P4(format) \
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((format) == IMAGE_P4_RGB565 || (format) == IMAGE_P4_RGB565A)
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/* Check whether image format has an alpha color */
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#define IMAGE_IS_ALPHA(format) \
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((format) == IMAGE_RGB565A || \
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(format) == IMAGE_P8_RGB565A || \
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(format) == IMAGE_P4_RGB565A)
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/* Check whether image format uses a palette */
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#define IMAGE_IS_INDEXED(format) \
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(IMAGE_IS_P8(format) || IMAGE_IS_P4(format))
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/* Image flags. These are used for memory management, mostly. */
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enum {
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IMAGE_FLAGS_DATA_RO = 0x01, /* Data is read-only */
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IMAGE_FLAGS_PALETTE_RO = 0x02, /* Palette is read-only */
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IMAGE_FLAGS_DATA_ALLOC = 0x04, /* Data is malloc()'d */
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IMAGE_FLAGS_PALETTE_ALLOC = 0x08, /* Palette is malloc()'d */
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};
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/* image_t: gint's native bitmap image format
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Images of this format can be created through this header's API but also by
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using the fxSDK's built-in image converters with fxconv. */
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typedef struct
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{
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/* Color format, one of the IMAGE_* values defined above */
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uint8_t format;
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/* Additional flags, a combination of IMAGE_FLAGS_* values */
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uint8_t flags;
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/* Number of colors in the palette; this includes alpha for transparent
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images, as alpha is always the first entry.
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RGB16: 0
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P8: Ranges between 1 and 256
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P4: 16 */
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int16_t color_count;
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/* Full width and height, in pixels */
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uint16_t width;
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uint16_t height;
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/* Byte stride between lines */
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uint32_t stride;
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/* Pixel data in row-major order, left to right.
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- RGB16: 2 bytes per entry, each row padded to 4 bytes for alignment.
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Each 2-byte value is an RGB565 color.
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- P8: 1 signed byte per entry. Each byte is a palette index shifted by
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128 (to access the color, use palette[<value>+128]).
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- P4: 4 bits per entry, each row padded to a full byte. Each entry is a
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direct palette index between 0 and 15. */
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void *data;
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/* For P8 and P4, color palette. The number of entries allocated in the
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array is equal to the color_count attribute. */
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uint16_t *palette;
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} __attribute__((packed, aligned(4))) bopti_image_t;
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#ifdef __cplusplus
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}
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#endif
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#endif // GINT_IMAGE
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