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Improve colour performance if compile-time PIXEL_COLOR_DEPTH_BITS is less than 8

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Refer to the code.
This commit is contained in:
mrfaptastic 2021-02-14 14:12:45 +00:00
parent 77e0abff90
commit 889ed51fe1
2 changed files with 28 additions and 14 deletions
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27
ESP32-HUB75-MatrixPanel-I2S-DMA.cpp
View file

@ -55,20 +55,26 @@
*/
// For development testing only
//#define IGNORE_REFRESH_RATE 1
#define val2PWM(val) { lumConvTab[(uint8_t)val]; }
// macro's to calculate sizes of a single buffer (double buffer takes twice as this)
#define rowBitStructBuffSize sizeof(ESP32_I2S_DMA_STORAGE_TYPE) * (PIXELS_PER_ROW + CLKS_DURING_LATCH) * PIXEL_COLOR_DEPTH_BITS
#define frameStructBuffSize ROWS_PER_FRAME * rowBitStructBuffSize
/* this replicates same function in rowBitStruct, but due to induced inlining it might be MUCH faster when used in tight loops
* while method from struct could be flushed out of instruction cache between loop cycles
* do NOT forget about buff_id param if using this
*/
#define getRowDataPtr(row, _dpth, buff_id) &(dma_buff.rowBits[row]->data[_dpth * dma_buff.rowBits[row]->width + buff_id*(dma_buff.rowBits[row]->width * dma_buff.rowBits[row]->color_depth)])
/* This library is designed to take an 8 bit / 1 byt value (0-255) for each R G B colour sub-pixel.
* The PIXEL_COLOR_DEPTH_BITS should always be '8' as a result.
* However, if the library is to be used with lower colour depth (i.e. 6 bit colour), then we need to ensure the 8-bit value passed to the colour masking
* is adjusted accordingly to ensure the LSB's are shifted left to MSB, by the difference. Otherwise the colours will be all screwed up.
*/
#if PIXEL_COLOR_DEPTH_BITS < 8
#define COLOR_DEPTH_LESS_THAN_8BIT_ADJUST +(8-PIXEL_COLOR_DEPTH_BITS)
#else
#define COLOR_DEPTH_LESS_THAN_8BIT_ADJUST // Nothing to adjust.
#endif
bool MatrixPanel_I2S_DMA::allocateDMAmemory()
{
@ -472,6 +478,7 @@ void IRAM_ATTR MatrixPanel_I2S_DMA::updateMatrixDMABuffer(int16_t x_coord, int16
* i.e. It's almost impossible for color_depth_idx of 0 to be sent out to the MATRIX unless the 'value' of a color is exactly '1'
* https://ledshield.wordpress.com/2012/11/13/led-brightness-to-your-eye-gamma-correction-no/
*/
red = lumConvTab[red];
green = lumConvTab[green];
blue = lumConvTab[blue];
@ -500,11 +507,11 @@ void IRAM_ATTR MatrixPanel_I2S_DMA::updateMatrixDMABuffer(int16_t x_coord, int16
y_coord -= ROWS_PER_FRAME;
}
// Iterating through color depth bits
// Iterating through colour depth bits, which we assume are 8 bits per RGB subpixel (24bpp)
uint8_t color_depth_idx = PIXEL_COLOR_DEPTH_BITS;
do {
--color_depth_idx;
uint8_t mask = (1 << color_depth_idx); // 24 bit color
uint8_t mask = (1 << (color_depth_idx COLOR_DEPTH_LESS_THAN_8BIT_ADJUST)); // expect 24 bit color (8 bits per RGB subpixel)
uint16_t RGB_output_bits = 0;
/* Per the .h file, the order of the output RGB bits is:
@ -544,7 +551,7 @@ void MatrixPanel_I2S_DMA::updateMatrixDMABuffer(uint8_t red, uint8_t green, uint
{
// let's precalculate RGB1 and RGB2 bits than flood it over the entire DMA buffer
uint16_t RGB_output_bits = 0;
uint8_t mask = (1 << color_depth_idx); // 24 bit color
uint8_t mask = (1 << color_depth_idx COLOR_DEPTH_LESS_THAN_8BIT_ADJUST); // 24 bit color
/* Per the .h file, the order of the output RGB bits is:
* BIT_B2, BIT_G2, BIT_R2, BIT_B1, BIT_G1, BIT_R1 */
@ -874,7 +881,7 @@ void MatrixPanel_I2S_DMA::hlineDMA(int16_t x_coord, int16_t y_coord, int16_t l,
// let's precalculate RGB1 and RGB2 bits than flood it over the entire DMA buffer
uint16_t RGB_output_bits = 0;
uint8_t mask = (1 << color_depth_idx);
uint8_t mask = (1 << color_depth_idx COLOR_DEPTH_LESS_THAN_8BIT_ADJUST);
/* Per the .h file, the order of the output RGB bits is:
* BIT_B2, BIT_G2, BIT_R2, BIT_B1, BIT_G1, BIT_R1 */
@ -934,7 +941,7 @@ void MatrixPanel_I2S_DMA::vlineDMA(int16_t x_coord, int16_t y_coord, int16_t l,
--color_depth_idx;
// let's precalculate RGB1 and RGB2 bits than flood it over the entire DMA buffer
uint8_t mask = (1 << color_depth_idx);
uint8_t mask = (1 << color_depth_idx COLOR_DEPTH_LESS_THAN_8BIT_ADJUST);
uint16_t RGB_output_bits = 0;
/* Per the .h file, the order of the output RGB bits is:

13
ESP32-HUB75-MatrixPanel-I2S-DMA.h
View file

@ -77,7 +77,7 @@
#endif
// 8bit per RGB color = 24 bit/per pixel,
// might be reduced to save RAM but it corrupts colors badly (curently broken)
// might be reduced to save RAM but it corrupts colours badly (currently broken)
#ifndef PIXEL_COLOR_DEPTH_BITS
#define PIXEL_COLOR_DEPTH_BITS 8
#endif
@ -85,9 +85,9 @@
#define COLOR_CHANNELS_PER_PIXEL 3
/***************************************************************************************/
/* Definitions below shold NOT be ever changed without rewriting libraly logic */
/* Definitions below should NOT be ever changed without rewriting library logic */
#define ESP32_I2S_DMA_MODE I2S_PARALLEL_BITS_16 // Pump 16 bits out in parallel
#define ESP32_I2S_DMA_STORAGE_TYPE uint16_t // one uint16_t at a time.
#define ESP32_I2S_DMA_STORAGE_TYPE uint16_t // DMA output of one uint16_t at a time.
#define CLKS_DURING_LATCH 0 // Not (yet) used.
// Panel Upper half RGB (numbering according to order in DMA gpio_bus configuration)
@ -126,6 +126,13 @@
// Max clock cycles to blank OE before/after LAT signal change
#define MAX_LAT_BLANKING 4
/***************************************************************************************/
// Check compile-time only options
#if PIXEL_COLOR_DEPTH_BITS > 8
#error "Pixel color depth bits cannot be greater than 8."
#elif PIXEL_COLOR_DEPTH_BITS < 1
#error "Pixel color depth bits cannot be less than 1."
#endif
/***************************************************************************************/
// Lib includes