66 lines
1.4 KiB
C
66 lines
1.4 KiB
C
#include <stdint.h>
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#include <stddef.h>
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#include <stdarg.h>
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#include <lib/libc.h>
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#include <lib/blib.h>
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#include <lib/print.h>
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#include <lib/trace.h>
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#include <lib/real.h>
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#include <fs/file.h>
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#if defined (uefi)
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EFI_SYSTEM_TABLE *gST;
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EFI_BOOT_SERVICES *gBS;
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EFI_RUNTIME_SERVICES *gRT;
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#endif
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bool parse_resolution(int *width, int *height, int *bpp, const char *buf) {
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int res[3] = {0};
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const char *first = buf;
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for (int i = 0; i < 3; i++) {
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const char *last;
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int x = strtoui(first, &last, 10);
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if (first == last)
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break;
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res[i] = x;
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if (*last == 0)
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break;
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first = last + 1;
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}
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if (res[0] == 0 || res[1] == 0)
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return false;
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if (res[2] == 0)
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res[2] = 32;
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*width = res[0], *height = res[1], *bpp = res[2];
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return true;
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}
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// This integer sqrt implementation has been adapted from:
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// https://stackoverflow.com/questions/1100090/looking-for-an-efficient-integer-square-root-algorithm-for-arm-thumb2
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uint64_t sqrt(uint64_t a_nInput) {
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uint64_t op = a_nInput;
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uint64_t res = 0;
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uint64_t one = (uint64_t)1 << 62;
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// "one" starts at the highest power of four <= than the argument.
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while (one > op) {
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one >>= 2;
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}
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while (one != 0) {
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if (op >= res + one) {
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op = op - (res + one);
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res = res + 2 * one;
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}
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res >>= 1;
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one >>= 2;
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}
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return res;
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}
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