static void lm70_chipselect(struct spi_device *spi, int value)
{
struct spi_lm70llp *pp = spidev_to_pp(spi);
if (value)
assertCS(pp);
else
deassertCS(pp);
}
template<typename SourceType> BMP_Status OLED::_displayBMP(SourceType &source, const int from_x, const int from_y, const int to_x, const int to_y)
{
SourceType &f = source;
f.seek(0);
// File header, check magic number 'BM'
if(f.read() != 'B' || f.read() != 'M')
return BMP_INVALID_FORMAT;
// Read DIB header with image properties
f.seek(OFFS_DIB_HEADER);
uint16_t dib_headersize = readLong(f);
uint16_t width, height, bpp, compression;
bool v2header = (dib_headersize == 12); // BMPv2 header, no compression, no additional options
if(v2header) {
width = readShort(f);
height = readShort(f);
if(readShort(f) != 1)
return BMP_UNSUPPORTED_HEADER;
bpp = readShort(f);
compression = BMP_NoCompression;
}
else {
width = readLong(f);
height = readLong(f);
if(readShort(f) != 1)
return BMP_UNSUPPORTED_HEADER;
bpp = readShort(f);
compression = readLong(f);
}
// Verify image properties from header
if(bpp > 24)
return BMP_TOO_MANY_COLOURS;
if(bpp != 1 && bpp != 4 && bpp != 8 && bpp != 16 && bpp != 24)
return BMP_UNSUPPORTED_COLOURS;
if(!(compression == BMP_NoCompression
|| (compression == BMP_BITFIELDS && bpp == 16))) {
return BMP_COMPRESSION_NOT_SUPPORTED;
}
// In case of the bitfields option, determine the pixel format. We support RGB565 & RGB555 only
bool rgb565 = true;
if(compression == BMP_BITFIELDS) {
f.seek(0x36);
uint16_t b = readLong(f);
uint16_t g = readLong(f);
uint16_t r = readLong(f);
if(r == 0x001f && g == 0x07e0 && b == 0xf800)
rgb565 = true;
else if(r != 0x001f && g != 0x03e0 && b != 0x7c00)
return BMP_UNSUPPORTED_COLOURS; // Not RGB555 either
}
if (width < from_x || height < from_y)
return BMP_ORIGIN_OUTSIDE_IMAGE; // source in BMP is offscreen
// Find the starting offset for the data in the first row
f.seek(0x0a);
uint32_t data_offs = readLong(f);
assertCS();
// Trim height to 128, anything bigger gets cut off, then set up row span in memory
height = height - from_y;
if(to_y + height > 128)
height = 128-to_y;
// Calculate outputtable width and set up column span in memory
uint16_t out_width = width - from_x;
if(to_x + out_width > 128)
out_width = 128-to_x;
// Calculate the width in bits of each row (rounded up to nearest byte)
uint16_t row_bits = (width*bpp + 7) & ~7;
// Calculate width in bytes (4-byte boundary aligned)
uint16_t row_bytes = (row_bits/8 + 3) & ~3;
startWrite(to_x,to_y,to_x+out_width-1,to_y+height-1,false);
releaseCS();
// Read colour palette to RAM. It's quite hefty to hold in RAM (512 bytes for a full 8-bit palette)
// but don't have much choice as seeking back and forth on SD is painfully slow
OLED_Colour *palette;
if(bpp < 16) {
uint16_t palette_size = 1<<bpp;
palette = (OLED_Colour *)malloc(sizeof(OLED_Colour)*palette_size);
f.seek(OFFS_DIB_HEADER + dib_headersize);
for(uint16_t i = 0; i < palette_size; i++) {
uint8_t pal[4];
f.read(pal, v2header ? 3 : 4);
palette[i].blue = pal[0] >> 3;
palette[i].green = pal[1] >> 2;
palette[i].red = pal[2] >> 3;
}
}
int OLED::drawChar(const int x, const int y, const char letter, const OLED_Colour colour, const OLED_Colour background)
{
if (x <0 || y < 0 || x >= COLUMNS || y >= ROWS) return -1;
struct FontHeader header;
memcpy_P(&header, (void*)this->font, sizeof(FontHeader));
uint8_t c = letter;
if (c == ' ') {
int charWide = charWidth(' ');
this->drawFilledBox(x, y-1, x + charWide, y + header.height, background);
return charWide;
}
uint8_t width = 0;
uint8_t bytes = (header.height + 7) / 8; // Number of bytes in a single column
uint16_t index = 0;
if (c < header.firstChar || c >= (header.firstChar + header.charCount)) return 0;
c -= header.firstChar;
if (header.size == 0) {
// zero length is flag indicating fixed width font (array does not contain width data entries)
width = header.fixedWidth;
index = sizeof(FontHeader) + c * bytes * width;
} else {
// variable width font, read width data, to get the index
for (uint8_t i = 0; i < c; i++) {
index += pgm_read_byte(this->font + sizeof(FontHeader) + i);
}
index = index * bytes + sizeof(FontHeader) + header.charCount;
width = pgm_read_byte(this->font + sizeof(FontHeader) + c);
}
if (x < -width || y < -header.height)
return width;
assertCS();
startWrite(x > 0 ? x : 0, y > 0 ? y : 0,
x+width > 127 ? 127 : x+width-1, y+header.height > 127 ? 127 : y+header.height-1,
true);
/* Characters are stored as follows:
*
* Each byte is up to 8 vertical pixels (LSB @ top)
* Each row of bytes is adjacent
* For fonts >8 pixels high, the bytes are strided by width
*
* ie for a font 16 pixels high and 8 pixels wide:
*
* P(0,0) P(0,1) P(1,0) P(1,1) P(2,0) P(2,1) P(3,0) P(3,1) ... etc
*
*
* Things are made more annoying for OLED because we need to write to the display
* bottom-to-top for each column, so striding backwards instead of forwards...
*/
for(int16_t ox = 0; ox < width; ox++) {
if(ox+x >= COLUMNS)
break;
int16_t oy = 0;
for(int8_t byte_y = bytes-1; byte_y >= 0; byte_y--) {
uint8_t data = pgm_read_byte(this->font + index + ox + byte_y * width);
int8_t start_bit;
int8_t end_bit;
if(bytes == 1) {
start_bit = header.height-1;
end_bit = 0;
}
else {
start_bit = 7;
end_bit = (byte_y < bytes-1) ? 0: 7-((header.height-1)%8);
}
for(int8_t bit_y = start_bit; bit_y >= end_bit; bit_y--) {
if(oy+y < ROWS && ox+x >= 0 && oy+y >= 0) {
writeData( (data & 1<<bit_y) ? colour : background);
}
oy++;
if(oy == header.height)
break;
}
}
}
releaseCS();
return width;
}
