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More documentation

This commit is contained in:
Peter Evans 2017-12-06 21:37:14 -06:00
parent ea2b68dc8c
commit dccf80be5d
3 changed files with 30 additions and 6 deletions

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@ -3,6 +3,11 @@
#include <stdlib.h>
/*
* We use the 8bit and 16bit types everywhere within the "vm"
* abstraction; they are also used where applicable within the other
* systems, like the mos6502 cpu, within the apple2 machine, etc.
*/
typedef uint8_t vm_8bit;
typedef uint16_t vm_16bit;

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@ -1,7 +1,18 @@
#ifndef _VM_SCREEN_H_
#define _VM_SCREEN_H_
/*
* If you just want to plot a single pixel, you can use this macro to
* abstract away the need to indicate the x/y dimensions (as those must
* necessarily be 1x1).
*/
#define vm_screen_draw_pixel(context, xpos, ypos) \
vm_screen_draw_rect(context, xpos, ypos, 1, 1)
typedef struct {
/*
* These form the components of an RGBA composite color.
*/
int color_red;
int color_green;
int color_blue;
@ -13,7 +24,4 @@ extern void vm_screen_free_context(vm_screen_context *);
extern vm_screen_context *vm_screen_new_context();
extern void vm_screen_set_color(vm_screen_context *, int, int, int, int);
#define vm_screen_draw_pixel(context, xpos, ypos) \
vm_screen_draw_rect(context, xpos, ypos, 1, 1)
#endif

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@ -3,8 +3,22 @@
#include "vm_bits.h"
/*
* The bounds check is just some inline code to try and cut down on the
* cost of it.
*/
#define vm_segment_bounds_check(segment, index) \
(index == index % segment->size)
typedef struct {
/*
* The size of our memory segment. This is used for bounds checking.
*/
size_t size;
/*
* This is the actual chunk of memory we allocate.
*/
vm_8bit *memory;
} vm_segment;
@ -14,7 +28,4 @@ extern void vm_segment_free(vm_segment *);
extern vm_8bit vm_segment_get(vm_segment *, size_t);
extern void vm_segment_set(vm_segment *, size_t, vm_8bit);
#define vm_segment_bounds_check(segment, index) \
(index == index % segment->size)
#endif