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Move float utility functions into utility.h

This commit is contained in:
Joshua Goins 2022-04-16 16:38:29 -04:00
parent 79c482ac97
commit d0e016e568
2 changed files with 45 additions and 39 deletions

View file

@ -4,6 +4,37 @@
template <class T>
void endianSwap(T *objp) {
auto memp = reinterpret_cast<unsigned char*>(objp);
auto memp = reinterpret_cast<uint8_t*>(objp);
std::reverse(memp, memp + sizeof(T));
}
// ported from lumina.halfextensions
static float half_to_float(const uint16_t value) {
unsigned int num3;
if ((value & -33792) == 0) {
if ((value & 0x3ff) != 0) {
auto num2 = 0xfffffff2;
auto num = (unsigned int) (value & 0x3ff);
while ((num & 0x400) == 0) {
num2--;
num <<= 1;
}
num &= 0xfffffbff;
num3 = ((unsigned int) (value & 0x8000) << 0x10) | ((num2 + 0x7f) << 0x17) | (num << 13);
} else {
num3 = (unsigned int) ((value & 0x8000) << 0x10);
}
} else {
num3 = (unsigned int)
(((value & 0x8000) << 0x10) |
((((value >> 10) & 0x1f) - 15 + 0x7f) << 0x17) |
((value & 0x3ff) << 13));
}
return *(float *)&num3;
}
static float byte_to_float(const uint8_t value) {
return static_cast<float>(value) / 255.0f;
}

View file

@ -1,4 +1,5 @@
#include "mdlparser.h"
#include "utility.h"
#include <cstdio>
#include <stdexcept>
@ -7,37 +8,6 @@
#include <fstream>
#include <algorithm>
using ushort = unsigned short;
using uint = unsigned int;
// from lumina.halfextensions
static float Unpack(ushort value) {
uint num3;
if ((value & -33792) == 0) {
if ((value & 0x3ff) != 0) {
auto num2 = 0xfffffff2;
auto num = (uint) (value & 0x3ff);
while ((num & 0x400) == 0) {
num2--;
num <<= 1;
}
num &= 0xfffffbff;
num3 = ((uint) (value & 0x8000) << 0x10) | ((num2 + 0x7f) << 0x17) | (num << 13);
} else {
num3 = (uint) ((value & 0x8000) << 0x10);
}
} else {
num3 =
(uint)
(((value & 0x8000) << 0x10) |
((((value >> 10) & 0x1f) - 15 + 0x7f) << 0x17) |
((value & 0x3ff) << 13));
}
return *(float *) &num3;
}
Model parseMDL(const std::string_view path) {
FILE* file = fopen(path.data(), "rb");
if(file == nullptr) {
@ -384,22 +354,27 @@ Model parseMDL(const std::string_view path) {
fseek(file, sizeof(uint8_t) * 4, SEEK_CUR);
break;
case VertexType::ByteFloat4:
fseek(file, sizeof(uint8_t) * 4, SEEK_CUR);
uint8_t values[4];
fread(values, sizeof(uint8_t) * 4, 1, file);
floatData[0] = byte_to_float(values[0]);
floatData[1] = byte_to_float(values[1]);
floatData[2] = byte_to_float(values[2]);
floatData[3] = byte_to_float(values[3]);
break;
case VertexType::Half2: {
uint16_t values[2];
fread(values, sizeof(uint16_t) * 2, 1, file);
floatData[0] = Unpack(values[0]);
floatData[1] = Unpack(values[1]);
floatData[0] = half_to_float(values[0]);
floatData[1] = half_to_float(values[1]);
}
break;
case VertexType::Half4: {
uint16_t values[4];
fread(values, sizeof(uint16_t) * 4, 1, file);
floatData[0] = Unpack(values[0]);
floatData[1] = Unpack(values[1]);
floatData[2] = Unpack(values[2]);
floatData[3] = Unpack(values[3]);
floatData[0] = half_to_float(values[0]);
floatData[1] = half_to_float(values[1]);
floatData[2] = half_to_float(values[2]);
floatData[3] = half_to_float(values[3]);
}
break;
}