RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 09:58:11 +00:00
Code Issues Activity Actions

LibGfx: Use gamma-corrected interpolation for color gradients

Browse source 
Switch over to gamma-aware interpolation. This causes color gradients
to not look so dark in the middle. SIMD optimized code is provided for
sse1 enabled builds.

Fixes #1342.
This commit is contained in:
Sahan Fernando 2020-11-17 02:35:41 +11:00 • committed by Andreas Kling
parent 7042490e41
commit 1b9a85e4f1
3 changed files with 165 additions and 21 deletions
Download patch file Download diff file Expand all files Collapse all files

21
Libraries/LibGfx/Painter.cpp
View file

@ -28,6 +28,7 @@
#include "Bitmap.h"
#include "Emoji.h"
#include "Font.h"
#include "Gamma.h"
#include <AK/Assertions.h>
#include <AK/Function.h>
#include <AK/Memory.h>
@ -200,24 +201,13 @@ void Painter::fill_rect_with_gradient(Orientation orientation, const IntRect& a_
RGBA32* dst = m_target->scanline(clipped_rect.top()) + clipped_rect.left();
const size_t dst_skip = m_target->pitch() / sizeof(RGBA32);
float increment = (1.0 / ((rect.primary_size_for_orientation(orientation)) / 255.0));
int r2 = gradient_start.red();
int g2 = gradient_start.green();
int b2 = gradient_start.blue();
int r1 = gradient_end.red();
int g1 = gradient_end.green();
int b1 = gradient_end.blue();
float increment = (1.0 / ((rect.primary_size_for_orientation(orientation))));
if (orientation == Orientation::Horizontal) {
for (int i = clipped_rect.height() - 1; i >= 0; --i) {
float c = offset * increment;
for (int j = 0; j < clipped_rect.width(); ++j) {
dst[j] = Color(
r1 / 255.0 * c + r2 / 255.0 * (255 - c),
g1 / 255.0 * c + g2 / 255.0 * (255 - c),
b1 / 255.0 * c + b2 / 255.0 * (255 - c))
.value();
dst[j] = gamma_accurate_blend(gradient_start, gradient_end, c).value();
c += increment;
}
dst += dst_skip;
@ -225,10 +215,7 @@ void Painter::fill_rect_with_gradient(Orientation orientation, const IntRect& a_
} else {
float c = offset * increment;
for (int i = clipped_rect.height() - 1; i >= 0; --i) {
Color color(
r1 / 255.0 * c + r2 / 255.0 * (255 - c),
g1 / 255.0 * c + g2 / 255.0 * (255 - c),
b1 / 255.0 * c + b2 / 255.0 * (255 - c));
auto color = gamma_accurate_blend(gradient_start, gradient_end, c);
for (int j = 0; j < clipped_rect.width(); ++j) {
dst[j] = color.value();
}