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Userland: static vs non-static constexpr variables

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Problem:
- `static` variables consume memory and sometimes are less
  optimizable.
- `static const` variables can be `constexpr`, usually.
- `static` function-local variables require an initialization check
  every time the function is run.

Solution:
- If a global `static` variable is only used in a single function then
  move it into the function and make it non-`static` and `constexpr`.
- Make all global `static` variables `constexpr` instead of `const`.
- Change function-local `static const[expr]` variables to be just
  `constexpr`.
This commit is contained in:
Lenny Maiorani 2021-05-19 09:32:07 -06:00 • committed by Linus Groh
parent 17ff895e1c
commit 800ea8ea96
38 changed files with 192 additions and 184 deletions
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35
Userland/Demos/Fire/Fire.cpp
View file

@ -22,6 +22,7 @@
* [ ] handle fire bitmap edges better
*/
#include <AK/Array.h>
#include <LibCore/ElapsedTimer.h>
#include <LibGUI/Action.h>
#include <LibGUI/Application.h>
@ -38,22 +39,9 @@
#include <time.h>
#include <unistd.h>
#define FIRE_WIDTH 320
#define FIRE_HEIGHT 168
#define FIRE_MAX 29
static const Color s_palette[] = {
Color(0x07, 0x07, 0x07), Color(0x1F, 0x07, 0x07), Color(0x2F, 0x0F, 0x07),
Color(0x47, 0x0F, 0x07), Color(0x57, 0x17, 0x07), Color(0x67, 0x1F, 0x07),
Color(0x77, 0x1F, 0x07), Color(0x9F, 0x2F, 0x07), Color(0xAF, 0x3F, 0x07),
Color(0xBF, 0x47, 0x07), Color(0xC7, 0x47, 0x07), Color(0xDF, 0x4F, 0x07),
Color(0xDF, 0x57, 0x07), Color(0xD7, 0x5F, 0x07), Color(0xD7, 0x5F, 0x07),
Color(0xD7, 0x67, 0x0F), Color(0xCF, 0x6F, 0x0F), Color(0xCF, 0x7F, 0x0F),
Color(0xCF, 0x87, 0x17), Color(0xC7, 0x87, 0x17), Color(0xC7, 0x8F, 0x17),
Color(0xC7, 0x97, 0x1F), Color(0xBF, 0x9F, 0x1F), Color(0xBF, 0xA7, 0x27),
Color(0xBF, 0xAF, 0x2F), Color(0xB7, 0xAF, 0x2F), Color(0xB7, 0xB7, 0x37),
Color(0xCF, 0xCF, 0x6F), Color(0xEF, 0xEF, 0xC7), Color(0xFF, 0xFF, 0xFF)
};
static constexpr auto FIRE_WIDTH = 320;
static constexpr auto FIRE_HEIGHT = 168;
static constexpr auto FIRE_MAX = 29;
class Fire : public GUI::Widget {
C_OBJECT(Fire)
@ -80,11 +68,24 @@ private:
Fire::Fire()
{
constexpr Array palette = {
Color(0x07, 0x07, 0x07), Color(0x1F, 0x07, 0x07), Color(0x2F, 0x0F, 0x07),
Color(0x47, 0x0F, 0x07), Color(0x57, 0x17, 0x07), Color(0x67, 0x1F, 0x07),
Color(0x77, 0x1F, 0x07), Color(0x9F, 0x2F, 0x07), Color(0xAF, 0x3F, 0x07),
Color(0xBF, 0x47, 0x07), Color(0xC7, 0x47, 0x07), Color(0xDF, 0x4F, 0x07),
Color(0xDF, 0x57, 0x07), Color(0xD7, 0x5F, 0x07), Color(0xD7, 0x5F, 0x07),
Color(0xD7, 0x67, 0x0F), Color(0xCF, 0x6F, 0x0F), Color(0xCF, 0x7F, 0x0F),
Color(0xCF, 0x87, 0x17), Color(0xC7, 0x87, 0x17), Color(0xC7, 0x8F, 0x17),
Color(0xC7, 0x97, 0x1F), Color(0xBF, 0x9F, 0x1F), Color(0xBF, 0xA7, 0x27),
Color(0xBF, 0xAF, 0x2F), Color(0xB7, 0xAF, 0x2F), Color(0xB7, 0xB7, 0x37),
Color(0xCF, 0xCF, 0x6F), Color(0xEF, 0xEF, 0xC7), Color(0xFF, 0xFF, 0xFF)
};
bitmap = Gfx::Bitmap::create(Gfx::BitmapFormat::Indexed8, { 320, 200 });
/* Initialize fire palette */
for (int i = 0; i < 30; i++)
bitmap->set_palette_color(i, s_palette[i]);
bitmap->set_palette_color(i, palette[i]);
/* Set remaining entries to white */
for (int i = 30; i < 256; i++)