123 lines
3.6 KiB
C
123 lines
3.6 KiB
C
/*
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* This file is part of Luma3DS
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* Copyright (C) 2016-2020 Aurora Wright, TuxSH
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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* Additional Terms 7.b and 7.c of GPLv3 apply to this file:
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* * Requiring preservation of specified reasonable legal notices or
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* author attributions in that material or in the Appropriate Legal
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* Notices displayed by works containing it.
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* * Prohibiting misrepresentation of the origin of that material,
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* or requiring that modified versions of such material be marked in
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* reasonable ways as different from the original version.
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*/
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#include <3ds.h>
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#include <math.h>
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#include "luminance.h"
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#include "utils.h"
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extern bool isN3DS;
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typedef struct BlPwmData
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{
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float coeffs[3][3];
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u8 numLevels;
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u8 unk;
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u16 luminanceLevels[7];
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u16 brightnessMax;
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u16 brightnessMin;
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} BlPwmData;
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// Calibration, with (dubious) default values as fallback
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static BlPwmData s_blPwmData = {
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.coeffs = {
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{ 0.00111639f, 1.41412f, 0.07178809f },
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{ 0.000418169f, 0.66567f, 0.06098654f },
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{ 0.00208543f, 1.55639f, 0.0385939f }
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},
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.numLevels = 5,
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.unk = 0,
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.luminanceLevels = { 20, 43, 73, 95, 117, 172, 172 },
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.brightnessMax = 512,
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.brightnessMin = 13,
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};
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static inline float getPwmRatio(u32 brightnessMax, u32 pwmCnt)
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{
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u32 val = (pwmCnt & 0x10000) ? pwmCnt & 0x3FF : 511; // check pwm enabled flag
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return (float)brightnessMax / (val + 1);
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}
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// nn's asm has rounding errors (originally at 10^-3)
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static inline u32 luminanceToBrightness(u32 luminance, const float coeffs[3], u32 minLuminance, float pwmRatio)
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{
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float x = (float)luminance;
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float y = coeffs[0]*x*x + coeffs[1]*x + coeffs[2];
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y = (y <= minLuminance ? (float)minLuminance : y) / pwmRatio;
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return (u32)(y + 0.5f);
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}
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static inline u32 brightnessToLuminance(u32 brightness, const float coeffs[3], float pwmRatio)
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{
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// Find polynomial root of ax^2 + bx + c = y
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float y = (float)brightness * pwmRatio;
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float a = coeffs[0];
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float b = coeffs[1];
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float c = coeffs[2] - y;
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float x0 = (-b + sqrtf(b*b - 4.0f*a*c)) / (a + a);
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return (u32)(x0 + 0.5f);
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}
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static void readCalibration(void)
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{
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static bool calibRead = false;
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if (!calibRead) {
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cfguInit();
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calibRead = R_SUCCEEDED(CFG_GetConfigInfoBlk8(sizeof(BlPwmData), 0x50002, &s_blPwmData));
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cfguExit();
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}
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}
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u32 getMinLuminancePreset(void)
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{
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readCalibration();
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return s_blPwmData.luminanceLevels[0];
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}
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u32 getMaxLuminancePreset(void)
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{
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readCalibration();
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return s_blPwmData.luminanceLevels[s_blPwmData.numLevels - 1];
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}
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u32 getCurrentLuminance(bool top)
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{
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u32 regbase = top ? 0x10202200 : 0x10202A00;
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readCalibration();
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const float *coeffs = s_blPwmData.coeffs[top ? (isN3DS ? 2 : 1) : 0];
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u32 brightness = REG32(regbase + 0x40);
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float ratio = getPwmRatio(s_blPwmData.brightnessMax, REG32(regbase + 0x44));
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return brightnessToLuminance(brightness, coeffs, ratio);
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}
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