Atlas - VGA.C
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[FILE BEGIN]
1#include <dos.h>
2#include <conio.h>
3#include "VGA.H"
4
5unsigned char far *vga = (unsigned char far *)MK_FP(VGA_SEG, 0);
6static uint8_t g_cls_color = 0;
7extern char font8x8_basic[128][8];
8
9static int in_gfx_bounds(int x, int y)
10{
11    if (x < 0 || x >= 320)
12        return 0;
13    if (y < 0 || y >= 200)
14        return 0;
15    return 1;
16}
17
18static void swap_u16(uint16_t *a, uint16_t *b)
19{
20    uint16_t temp = *a;
21    *a = *b;
22    *b = temp;
23}
24
25void vga_set_mode(uint8_t mode)
26{
27    union REGS regs;
28    regs.h.ah = 0x00;
29    regs.h.al = mode;
30    int86(0x10, &regs, &regs);
31}
32
33
34void vga_text_setcolor(uint8_t fg, uint8_t bg)
35{
36    textcolor(fg & 0x0F);
37    textbackground(bg & 0x0F);
38}
39
40void vga_text_gotoxy(uint8_t x, uint8_t y)
41{
42    gotoxy((int)x + 1, (int)y + 1);
43}
44
45void vga_text_putch(char c)
46{
47    putch(c);
48}
49
50void vga_text_puts(const char *str)
51{
52    cputs(str);
53}
54
55void vga_text_cls(void)
56{
57    clrscr();
58}
59
60void vga_set_palette(uint8_t index, uint8_t r, uint8_t g, uint8_t b)
61{
62    outp(0x3C8, index);
63    outp(0x3C9, r);
64    outp(0x3C9, g);
65    outp(0x3C9, b);
66}
67
68void vga_gfx_setclscolor(uint8_t color)
69{
70    g_cls_color = color;
71}
72
73void vga_gfx_cls(void)
74{
75    int i;
76    for (i = 0; i < 320 * 200; i++)
77        vga[i] = g_cls_color;
78}
79
80void vga_gfx_putpixel(uint16_t x, uint16_t y, uint8_t color)
81{
82    if (!in_gfx_bounds((int)x, (int)y))
83        return;
84
85    vga[(unsigned int)y * 320u + (unsigned int)x] = color;
86}
87
88void vga_gfx_line(uint16_t x1, uint16_t y1, uint16_t x2, uint16_t y2, uint8_t color)
89{
90    int dx, dy, sx, sy, err, e2;
91    int cx = (int)x1;
92    int cy = (int)y1;
93    int tx = (int)x2;
94    int ty = (int)y2;
95
96    dx = (tx > cx) ? (tx - cx) : (cx - tx);
97    dy = (ty > cy) ? (ty - cy) : (cy - ty);
98    sx = (cx < tx) ? 1 : -1;
99    sy = (cy < ty) ? 1 : -1;
100    err = dx - dy;
101
102    for (;;)
103    {
104        if (in_gfx_bounds(cx, cy))
105            vga[cy * 320 + cx] = color;
106
107        if (cx == tx && cy == ty)
108            break;
109
110        e2 = err << 1;
111        if (e2 > -dy)
112        {
113            err -= dy;
114            cx += sx;
115        }
116        if (e2 < dx)
117        {
118            err += dx;
119            cy += sy;
120        }
121    }
122}
123
124void vga_gfx_rect(uint16_t x1, uint16_t y1, uint16_t x2, uint16_t y2, uint8_t color)
125{
126    if (x2 < x1)
127        swap_u16(&x1, &x2);
128    if (y2 < y1)
129        swap_u16(&y1, &y2);
130
131    vga_gfx_line(x1, y1, x2, y1, color);
132    vga_gfx_line(x2, y1, x2, y2, color);
133    vga_gfx_line(x2, y2, x1, y2, color);
134    vga_gfx_line(x1, y2, x1, y1, color);
135}
136
137void vga_gfx_circle(uint16_t x, uint16_t y, uint16_t radius, uint8_t color)
138{
139    int cx = (int)x;
140    int cy = (int)y;
141    int r = (int)radius;
142    int px = r;
143    int py = 0;
144    int err = 0;
145
146    while (px >= py)
147    {
148        vga_gfx_putpixel((uint16_t)(cx + px), (uint16_t)(cy + py), color);
149        vga_gfx_putpixel((uint16_t)(cx + py), (uint16_t)(cy + px), color);
150        vga_gfx_putpixel((uint16_t)(cx - py), (uint16_t)(cy + px), color);
151        vga_gfx_putpixel((uint16_t)(cx - px), (uint16_t)(cy + py), color);
152        vga_gfx_putpixel((uint16_t)(cx - px), (uint16_t)(cy - py), color);
153        vga_gfx_putpixel((uint16_t)(cx - py), (uint16_t)(cy - px), color);
154        vga_gfx_putpixel((uint16_t)(cx + py), (uint16_t)(cy - px), color);
155        vga_gfx_putpixel((uint16_t)(cx + px), (uint16_t)(cy - py), color);
156
157        if (err <= 0)
158        {
159            py++;
160            err += (py << 1) + 1;
161        }
162        if (err > 0)
163        {
164            px--;
165            err -= (px << 1) + 1;
166        }
167    }
168}
169
170void vga_gfx_putch(char c, int x, int y, uint8_t color)
171{
172    int row;
173    int col;
174    uint8_t bits;
175    uint8_t glyph = (uint8_t)c;
176
177    if (glyph >= 128)
178        glyph = (uint8_t)'?';
179
180    for (row = 0; row < 8; row++)
181    {
182        bits = (uint8_t)font8x8_basic[glyph][row];
183        for (col = 0; col < 8; col++)
184        {
185            if (bits & (1u << col))
186                vga_gfx_putpixel((uint16_t)(x + col), (uint16_t)(y + row), color);
187        }
188    }
189}
190
191void vga_gfx_puts(const char *str, int x, int y, uint8_t color)
192{
193    int cx = x;
194
195    while (*str)
196    {
197        if (*str == '\n')
198        {
199            cx = x;
200            y += 8;
201        }
202        else
203        {
204            vga_gfx_putch(*str, cx, y, color);
205            cx += 8;
206        }
207        str++;
208    }
209}
210
211void set_mode(unsigned char mode)
212{
213    vga_set_mode((uint8_t)mode);
214}
215
216void set_palette(unsigned char index, unsigned char r, unsigned char g, unsigned char b)
217{
218    vga_set_palette((uint8_t)index, (uint8_t)r, (uint8_t)g, (uint8_t)b);
219}
220
221void clear_screen(unsigned char color)
222{
223    vga_gfx_setclscolor((uint8_t)color);
224    vga_gfx_cls();
225}
226
227void put_pixel(int x, int y, unsigned char color)
228{
229    if (x < 0 || y < 0)
230        return;
231
232    vga_gfx_putpixel((uint16_t)x, (uint16_t)y, (uint8_t)color);
233}
234
235void vga_reset(void)
236{
237    vga_set_mode(VGA_MODE_TEXT_80x25);
238    clrscr();
239    textcolor(15);
240    textbackground(0);
241}
[FILE END]
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