From 5a852cb00d56342f7e013d0ca6e14b10a9c4b84c Mon Sep 17 00:00:00 2001 From: Rayyan Ansari Date: Tue, 16 Apr 2024 23:06:44 +0100 Subject: [PATCH] ROMManager: optimise ROMIcon function Precompute all 16 5-bit RGB palette colours into 8-bit RGBA to avoid repeated and superfluous calculation within the nested loop at the point of index lookup. A speedup was observed, from ~7ms, to a consistent 1ms (i.e. now practically instantaneous) through timing with std::chrono::high_resolution_clock. Also improve comprehensibility, by using meaningful names, where appropriate, for loop counter variables. --- src/frontend/qt_sdl/ROMManager.cpp | 31 +++++++++++++++++------------- 1 file changed, 18 insertions(+), 13 deletions(-) diff --git a/src/frontend/qt_sdl/ROMManager.cpp b/src/frontend/qt_sdl/ROMManager.cpp index bff9e4ca..a2b1ab75 100644 --- a/src/frontend/qt_sdl/ROMManager.cpp +++ b/src/frontend/qt_sdl/ROMManager.cpp @@ -1572,23 +1572,28 @@ QString GBACartLabel() void ROMIcon(const u8 (&data)[512], const u16 (&palette)[16], u32 (&iconRef)[32*32]) { - int index = 0; - for (int i = 0; i < 4; i++) + u32 paletteRGBA[16]; + for (int i = 0; i < 16; i++) { - for (int j = 0; j < 4; j++) + u8 r = ((palette[i] >> 0) & 0x1F) * 255 / 31; + u8 g = ((palette[i] >> 5) & 0x1F) * 255 / 31; + u8 b = ((palette[i] >> 10) & 0x1F) * 255 / 31; + u8 a = i ? 255 : 0; + paletteRGBA[i] = r | (g << 8) | (b << 16) | (a << 24); + } + + int count = 0; + for (int ytile = 0; ytile < 4; ytile++) + { + for (int xtile = 0; xtile < 4; xtile++) { - for (int k = 0; k < 8; k++) + for (int ypixel = 0; ypixel < 8; ypixel++) { - for (int l = 0; l < 8; l++) + for (int xpixel = 0; xpixel < 8; xpixel++) { - u8 pal_index = index % 2 ? data[index/2] >> 4 : data[index/2] & 0x0F; - u8 r = ((palette[pal_index] >> 0) & 0x1F) * 255 / 31; - u8 g = ((palette[pal_index] >> 5) & 0x1F) * 255 / 31; - u8 b = ((palette[pal_index] >> 10) & 0x1F) * 255 / 31; - u8 a = pal_index ? 255: 0; - u32* row = &iconRef[256 * i + 32 * k + 8 * j]; - row[l] = r | (g << 8) | (b << 16) | (a << 24); - index++; + u8 pal_index = count % 2 ? data[count/2] >> 4 : data[count/2] & 0x0F; + iconRef[ytile*256 + ypixel*32 + xtile*8 + xpixel] = paletteRGBA[pal_index]; + count++; } } }