common/color: Get rid of undefined behavior

Gets rid of type punning via reinterpret_cast within functions. Instead,
we use memcpy to transfer the contents across types.
This commit is contained in:
Lioncash 2018-08-08 16:00:07 -04:00 committed by zhupengfei
parent 0233f3286c
commit b956a2be1c

View File

@ -4,6 +4,8 @@
#pragma once #pragma once
#include <cstring>
#include "common/common_types.h" #include "common/common_types.h"
#include "common/swap.h" #include "common/swap.h"
#include "common/vector_math.h" #include "common/vector_math.h"
@ -83,7 +85,8 @@ inline const Math::Vec4<u8> DecodeRG8(const u8* bytes) {
* @return Result color decoded as Math::Vec4<u8> * @return Result color decoded as Math::Vec4<u8>
*/ */
inline const Math::Vec4<u8> DecodeRGB565(const u8* bytes) { inline const Math::Vec4<u8> DecodeRGB565(const u8* bytes) {
const u16_le pixel = *reinterpret_cast<const u16_le*>(bytes); u16_le pixel;
std::memcpy(&pixel, bytes, sizeof(pixel));
return {Convert5To8((pixel >> 11) & 0x1F), Convert6To8((pixel >> 5) & 0x3F), return {Convert5To8((pixel >> 11) & 0x1F), Convert6To8((pixel >> 5) & 0x3F),
Convert5To8(pixel & 0x1F), 255}; Convert5To8(pixel & 0x1F), 255};
} }
@ -94,7 +97,8 @@ inline const Math::Vec4<u8> DecodeRGB565(const u8* bytes) {
* @return Result color decoded as Math::Vec4<u8> * @return Result color decoded as Math::Vec4<u8>
*/ */
inline const Math::Vec4<u8> DecodeRGB5A1(const u8* bytes) { inline const Math::Vec4<u8> DecodeRGB5A1(const u8* bytes) {
const u16_le pixel = *reinterpret_cast<const u16_le*>(bytes); u16_le pixel;
std::memcpy(&pixel, bytes, sizeof(pixel));
return {Convert5To8((pixel >> 11) & 0x1F), Convert5To8((pixel >> 6) & 0x1F), return {Convert5To8((pixel >> 11) & 0x1F), Convert5To8((pixel >> 6) & 0x1F),
Convert5To8((pixel >> 1) & 0x1F), Convert1To8(pixel & 0x1)}; Convert5To8((pixel >> 1) & 0x1F), Convert1To8(pixel & 0x1)};
} }
@ -105,7 +109,8 @@ inline const Math::Vec4<u8> DecodeRGB5A1(const u8* bytes) {
* @return Result color decoded as Math::Vec4<u8> * @return Result color decoded as Math::Vec4<u8>
*/ */
inline const Math::Vec4<u8> DecodeRGBA4(const u8* bytes) { inline const Math::Vec4<u8> DecodeRGBA4(const u8* bytes) {
const u16_le pixel = *reinterpret_cast<const u16_le*>(bytes); u16_le pixel;
std::memcpy(&pixel, bytes, sizeof(pixel));
return {Convert4To8((pixel >> 12) & 0xF), Convert4To8((pixel >> 8) & 0xF), return {Convert4To8((pixel >> 12) & 0xF), Convert4To8((pixel >> 8) & 0xF),
Convert4To8((pixel >> 4) & 0xF), Convert4To8(pixel & 0xF)}; Convert4To8((pixel >> 4) & 0xF), Convert4To8(pixel & 0xF)};
} }
@ -116,7 +121,9 @@ inline const Math::Vec4<u8> DecodeRGBA4(const u8* bytes) {
* @return Depth value as an u32 * @return Depth value as an u32
*/ */
inline u32 DecodeD16(const u8* bytes) { inline u32 DecodeD16(const u8* bytes) {
return *reinterpret_cast<const u16_le*>(bytes); u16_le data;
std::memcpy(&data, bytes, sizeof(data));
return data;
} }
/** /**
@ -175,8 +182,10 @@ inline void EncodeRG8(const Math::Vec4<u8>& color, u8* bytes) {
* @param bytes Destination pointer to store encoded color * @param bytes Destination pointer to store encoded color
*/ */
inline void EncodeRGB565(const Math::Vec4<u8>& color, u8* bytes) { inline void EncodeRGB565(const Math::Vec4<u8>& color, u8* bytes) {
*reinterpret_cast<u16_le*>(bytes) = const u16_le data =
(Convert8To5(color.r()) << 11) | (Convert8To6(color.g()) << 5) | Convert8To5(color.b()); (Convert8To5(color.r()) << 11) | (Convert8To6(color.g()) << 5) | Convert8To5(color.b());
std::memcpy(bytes, &data, sizeof(data));
} }
/** /**
@ -185,9 +194,10 @@ inline void EncodeRGB565(const Math::Vec4<u8>& color, u8* bytes) {
* @param bytes Destination pointer to store encoded color * @param bytes Destination pointer to store encoded color
*/ */
inline void EncodeRGB5A1(const Math::Vec4<u8>& color, u8* bytes) { inline void EncodeRGB5A1(const Math::Vec4<u8>& color, u8* bytes) {
*reinterpret_cast<u16_le*>(bytes) = (Convert8To5(color.r()) << 11) | const u16_le data = (Convert8To5(color.r()) << 11) | (Convert8To5(color.g()) << 6) |
(Convert8To5(color.g()) << 6) |
(Convert8To5(color.b()) << 1) | Convert8To1(color.a()); (Convert8To5(color.b()) << 1) | Convert8To1(color.a());
std::memcpy(bytes, &data, sizeof(data));
} }
/** /**
@ -196,9 +206,10 @@ inline void EncodeRGB5A1(const Math::Vec4<u8>& color, u8* bytes) {
* @param bytes Destination pointer to store encoded color * @param bytes Destination pointer to store encoded color
*/ */
inline void EncodeRGBA4(const Math::Vec4<u8>& color, u8* bytes) { inline void EncodeRGBA4(const Math::Vec4<u8>& color, u8* bytes) {
*reinterpret_cast<u16_le*>(bytes) = (Convert8To4(color.r()) << 12) | const u16 data = (Convert8To4(color.r()) << 12) | (Convert8To4(color.g()) << 8) |
(Convert8To4(color.g()) << 8) |
(Convert8To4(color.b()) << 4) | Convert8To4(color.a()); (Convert8To4(color.b()) << 4) | Convert8To4(color.a());
std::memcpy(bytes, &data, sizeof(data));
} }
/** /**
@ -207,7 +218,8 @@ inline void EncodeRGBA4(const Math::Vec4<u8>& color, u8* bytes) {
* @param bytes Pointer where to store the encoded value * @param bytes Pointer where to store the encoded value
*/ */
inline void EncodeD16(u32 value, u8* bytes) { inline void EncodeD16(u32 value, u8* bytes) {
*reinterpret_cast<u16_le*>(bytes) = value & 0xFFFF; const u16_le data = static_cast<u16>(value);
std::memcpy(bytes, &data, sizeof(data));
} }
/** /**