added monochrome, 8bpp indexed, and 32bpp ARGB BMPs

2 files changed, 73 insertions, 35 deletions

diff --git a/shared-module/displayio/OnDiskBitmap.c b/shared-module/displayio/OnDiskBitmap.c
index bc3064632..76d8fb2d1 100644
--- a/shared-module/displayio/OnDiskBitmap.c
+++ b/shared-module/displayio/OnDiskBitmap.c
@@ -56,42 +56,65 @@ void common_hal_displayio_ondiskbitmap_construct(displayio_ondiskbitmap_t *self,
     uint16_t bits_per_pixel = bmp_header[14];
     uint32_t compression = read_word(bmp_header, 15);
     uint32_t number_of_colors = read_word(bmp_header, 23);
+
+    bool indexed = ((bits_per_pixel <= 8) && (number_of_colors != 0));
     self->bitfield_compressed  = (compression == 3);
-    
-    self->grayscale = ((bits_per_pixel == 8) && (number_of_colors == 256));
+    self->bits_per_pixel = bits_per_pixel;
+    self->width = read_word(bmp_header, 9);
+    self->height = read_word(bmp_header, 11);
+
     if (bits_per_pixel == 16){
-        if (((header_size == 124) || (header_size == 56)) && (self->bitfield_compressed)) {
+        if (((header_size >= 56)) || (self->bitfield_compressed)) {
             self->r_bitmask = read_word(bmp_header, 27);
             self->g_bitmask = read_word(bmp_header, 29);
             self->b_bitmask = read_word(bmp_header, 31);
             
-            if (!((self->r_bitmask == 0xf800) && (self->g_bitmask == 0x07e0) && (self->b_bitmask == 0x001f))){
-                mp_raise_ValueError_varg(translate("Only 16bpp RGB 565 supported for bitfield compressed BMPs;  R:%x G:%x B:%x"), 
-                self->r_bitmask, self->g_bitmask, self->b_bitmask);
-            }
-        } else if (header_size == 40){ // no bitmasks means 5:5:5
+        } else { // no compression or short header means 5:5:5
             self->r_bitmask = 0x7c00;
             self->g_bitmask = 0x3e0;
             self->b_bitmask = 0x1f;
         }
+    } else if ((indexed) && (self->bits_per_pixel != 1)) {
+        uint16_t palette_size = number_of_colors * sizeof(uint32_t);
+        uint16_t palette_offset = 0xe + header_size;
+
+        self->palette_data = m_malloc(palette_size, false);
+
+        f_rewind(&self->file->fp);
+        f_lseek(&self->file->fp, palette_offset);
+
+        UINT palette_bytes_read;
+        if (f_read(&self->file->fp, self->palette_data, palette_size, &palette_bytes_read) != FR_OK) {
+            mp_raise_OSError(MP_EIO);
+        }
+        if (palette_bytes_read != palette_size) {
+            mp_raise_ValueError(translate("Unable to read color palette data"));
+        }
+
 
-    } else if (!(header_size == 12 || header_size == 40 || header_size == 108 || header_size == 124) ||
-        !(compression == 0)) {
+    } else if (!(header_size == 12 || header_size == 40 || header_size == 108 || header_size == 124)) {
         mp_raise_ValueError_varg(translate("Only Windows format, uncompressed BMP supported %d"), header_size);
     }
 
-    if (bits_per_pixel < 16 && !(self->grayscale)) {
-        mp_raise_ValueError_varg(translate("Only true color (24 bpp or higher), 16bpp 565 and 555, and 8bpp grayscale BMP supported %d"), bits_per_pixel);
+    if ((bits_per_pixel == 4 ) || (( bits_per_pixel == 8) && (number_of_colors == 0))) {
+        mp_raise_ValueError_varg(translate("Only monochrome, indexed 8bpp, and 16bpp or greater BMPs supported: %d"), bits_per_pixel);
     }
-    self->bytes_per_pixel = bits_per_pixel / 8;
-    self->width = read_word(bmp_header, 9);
-    self->height = read_word(bmp_header, 11);
-    uint32_t byte_width = self->width * self->bytes_per_pixel;
-    self->stride = byte_width;
-    // Rows are word aligned.
-    if (self->stride % 4 != 0) {
-        self->stride += 4 - self->stride % 4;
+
+    if (self->bits_per_pixel >=8){
+        self->stride = (self->width * (bits_per_pixel / 8));
+        // Rows are word aligned.
+        if (self->stride % 4 != 0) {
+            self->stride += 4 - self->stride % 4;
+        }
+
+    } else {
+        uint32_t bit_stride = self->width;
+        if (bit_stride % 32 != 0) {
+            bit_stride += 32 - bit_stride % 32;
+        }
+        self->stride = (bit_stride / 8);
     }
+   
 }
 
 
@@ -100,39 +123,54 @@ uint32_t common_hal_displayio_ondiskbitmap_get_pixel(displayio_ondiskbitmap_t *s
     if (x < 0 || x >= self->width || y < 0 || y >= self->height) {
         return 0;
     }
-    uint32_t location = self->data_offset + (self->height - y) * self->stride + x * self->bytes_per_pixel;
+    uint32_t location;
+    uint8_t bytes_per_pixel = (self->bits_per_pixel / 8)  ? (self->bits_per_pixel /8) : 1;
+    if (self->bits_per_pixel >= 8){
+        location = self->data_offset + (self->height - y) * self->stride + x * bytes_per_pixel;
+    } else {
+        location = self->data_offset + (self->height - y) * self->stride + x / 8;
+    }
     // We don't cache here because the underlying FS caches sectors.
     f_lseek(&self->file->fp, location);
     UINT bytes_read;
-    uint32_t pixel = 0;
-    uint32_t result = f_read(&self->file->fp, &pixel, self->bytes_per_pixel, &bytes_read);
+    uint32_t pixel = 0; // this name is stale
+    uint32_t result = f_read(&self->file->fp, &pixel, bytes_per_pixel, &bytes_read);
     if (result == FR_OK) {
         uint32_t tmp = 0;
         uint8_t red;
         uint8_t green;
         uint8_t blue;
-        if (self->grayscale){
-            red = pixel;
-            green = pixel;
-            blue = pixel;
-            tmp = (red << 16 | green << 8 | blue);
+        if (self->bits_per_pixel == 1){
+            uint8_t bit_offset = x%8;
+            tmp = ( pixel & (0x80 >> (bit_offset))) >> (7 - bit_offset);
+            if (tmp == 1) {
+                return 0x00FFFFFF;
+            } else {
+                return 0x00000000;
+            }
+        } else if (bytes_per_pixel == 1){ 
+            blue = ((self->palette_data[pixel] & 0xFF) >> 0);
+            red = ((self->palette_data[pixel] & 0xFF0000) >> 16);
+            green = ((self->palette_data[pixel] & 0xFF00) >> 8);
+            tmp = (red << 16 | green << 8 | blue );
             return tmp;
-        } else if (self->bytes_per_pixel == 2) {
-            if (self->bitfield_compressed){
+        } else if (bytes_per_pixel == 2) {
+            if (self->g_bitmask == 0x07e0){ // 565
                 red =((pixel & self->r_bitmask) >>11);
                 green = ((pixel & self->g_bitmask) >>5);
                 blue = ((pixel & self->b_bitmask) >> 0);
-            } else {
+            } else { // 555
                 red =((pixel & self->r_bitmask) >>10);
                 green = ((pixel & self->g_bitmask) >>4);
                 blue = ((pixel & self->b_bitmask) >> 0);
             }
             tmp = (red << 19 | green << 10 | blue << 3);
             return tmp;
-        }else {
+        }else if ((bytes_per_pixel == 4) && (self->bitfield_compressed)){
+            return pixel & 0x00FFFFFF;
+        } else {
             return pixel;
         }
-
     }
     return 0;
 }
diff --git a/shared-module/displayio/OnDiskBitmap.h b/shared-module/displayio/OnDiskBitmap.h
index 2102863d6..28426f11b 100644
--- a/shared-module/displayio/OnDiskBitmap.h
+++ b/shared-module/displayio/OnDiskBitmap.h
@@ -44,9 +44,9 @@ typedef struct {
     uint32_t g_bitmask;
     uint32_t b_bitmask;
     bool bitfield_compressed;
-    bool grayscale;
     pyb_file_obj_t* file;
-    uint8_t bytes_per_pixel;
+    uint8_t bits_per_pixel;
+    uint32_t* palette_data;
 } displayio_ondiskbitmap_t;
 
 #endif // MICROPY_INCLUDED_SHARED_MODULE_DISPLAYIO_ONDISKBITMAP_H