11 #define SC_INDEX 0x3c4
12 #define CRTC_INDEX 0x3d4
13 #define CRTC_DATA 0x3d5
18 /* this comes from Allegro */
19 typedef struct vesa_mode_info
21 unsigned short ModeAttributes;
22 unsigned char WinAAttributes;
23 unsigned char WinBAttributes;
24 unsigned short WinGranularity;
25 unsigned short WinSize;
26 unsigned short WinASegment;
27 unsigned short WinBSegment;
28 unsigned long WinFuncPtr;
29 unsigned short BytesPerScanLine;
30 unsigned short XResolution;
31 unsigned short YResolution;
32 unsigned char XCharSize;
33 unsigned char YCharSize;
34 unsigned char NumberOfPlanes;
35 unsigned char BitsPerPixel;
36 unsigned char NumberOfBanks;
37 unsigned char MemoryModel;
38 unsigned char BankSize;
39 unsigned char NumberOfImagePages;
40 unsigned char Reserved_page;
41 unsigned char RedMaskSize;
42 unsigned char RedMaskPos;
43 unsigned char GreenMaskSize;
44 unsigned char GreenMaskPos;
45 unsigned char BlueMaskSize;
46 unsigned char BlueMaskPos;
47 unsigned char ReservedMaskSize;
48 unsigned char ReservedMaskPos;
49 unsigned char DirectColorModeInfo;
50 unsigned long PhysBasePtr;
51 unsigned long OffScreenMemOffset;
52 unsigned short OffScreenMemSize;
53 unsigned char Reserved[206];
54 } __attribute__ ((packed)) vesa_mode_info;
57 int gr_vesa_checkmode(int mode) {
60 vesa_mode_info *mode_info;
62 if (!(mode_info = dpmi_get_temp_low_buffer( 1024 )))
66 rregs.edi = DPMI_real_offset(mode_info);
67 rregs.es = DPMI_real_segment(mode_info);
68 dpmi_real_int386x( 0x10, &rregs );
69 if (rregs.eax != 0x4f)
70 return 5; /* no vesa */
71 if (!(mode_info->ModeAttributes & 1))
72 return 4; /* unsupported mode */
75 i = mode_info->WinGranularity;
81 return 2; /* incompatible window granularity */
85 int gr_vesa_setmode(int mode) {
88 if ((ret = gr_vesa_checkmode(mode)))
90 asm volatile("int $0x10" : "=a" (ret) : "a" (0x4f02), "b" (mode));
91 return (ret == 0x4f) ? 0 : 4;
94 inline void gr_vesa_setpage(int bank) {
96 asm volatile("int $0x10"
97 : : "a" (0x4f05), "b" (0), "d" ((lastbank = bank) << bankshift));
100 void gr_vesa_incpage() {
101 gr_vesa_setpage(lastbank + 1);
104 void gr_vesa_setstart(int col, int row) {
105 asm volatile("int $0x10"
106 : : "a" (0x4f07), "b" (0), "c" (col), "d" (row));
109 int gr_vesa_setlogical(int line_width) {
111 asm volatile("int $0x10"
112 : "=c" (ret) : "a" (0x4f07), "b" (0), "c" (line_width));
116 void gr_vesa_scanline(int x1, int x2, int y, unsigned char color) {
117 int addr = (y * gr_var_bwidth) + x1;
118 int left = x2 - x1 + 1;
119 gr_vesa_setpage(addr >> 16);
122 if (left > (65536 - addr)) {
123 left -= (65536 - addr);
124 memset(gr_video_memory + addr, color, 65536 - addr);
128 memset(gr_video_memory + addr, color, left);
134 void gr_vesa_pixel(unsigned char color, unsigned int addr) {
135 gr_vesa_setpage(addr >> 16);
136 gr_video_memory[addr & 0xffff] = color;
140 #endif // __ENV_DJGPP__