lordtet
d6465ade55
Instead of passing function pointers, we're passing structs with context now. The idea is the same, I/O functions require some struct with a function pointer and some generic memory that only the output device cares about. I/O just calls it. VGA has been reworked to accomodate this change, as well as default outputs being created for low-overhead use (such as interrupt handlers).
43 lines
829 B
C
43 lines
829 B
C
/* vga.h
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* VGA
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*
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* Responsible for VGA buffer control.
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*/
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#ifndef VGA_H
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#define VGA_H
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#define VGA_GRID_COLS 80
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#define VGA_GRID_ROWS 25
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#define DEFAULT_ATTRIBUTES 0x0F00
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#include <stdint.h>
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#include <stdarg.h>
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#include "io.h"
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/*
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* CONSTANTS AND VARIABLES
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*/
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//Information on the VGA buffer
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extern volatile uint16_t* const vga_buffer;
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typedef struct vga_ctx_s {
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int cursor_col;
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int cursor_row;
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uint16_t attributes;
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} vga_ctx_t;
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//grid is top left origin. This is our cursor!
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extern uint16_t vga_attributes; // Black background, White foreground
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extern char_writer_t* default_vga;
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/*
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* Functions
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*/
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//Clear the VGA buffer, context optional
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void vga_clear_ctx(vga_ctx_t* ctx);
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void vga_clear();
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//Write character c to cursor
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//Implements IO generic ASCII output
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int vga_out(void* ctx, char c);
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#endif
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