Skip to content

Commit 6ad860a

Browse files
tannewttannewt
authored
Merge pull request #2101 from matthewnewberg/display_io_dither
Add random dithering to ColorConverter
2 parents bd7b03f + d9e0641 commit 6ad860a

File tree

10 files changed

+193
-49
lines changed

10 files changed

+193
-49
lines changed

‎shared-bindings/displayio/ColorConverter.c

Lines changed: 41 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -43,19 +43,27 @@
4343
//|
4444
//| Converts one color format to another.
4545
//|
46-
//| .. class:: ColorConverter()
46+
//| .. class:: ColorConverter(*, dither=False)
4747
//|
4848
//| Create a ColorConverter object to convert color formats. Only supports RGB888 to RGB565
4949
//| currently.
50-
//|
50+
//| :param bool dither: Adds random noise to dither the output image
51+
5152
// TODO(tannewt): Add support for other color formats.
5253
//|
5354
STATIC mp_obj_t displayio_colorconverter_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
54-
mp_arg_check_num(n_args, kw_args, 0, 0, false);
55+
enum { ARG_dither};
56+
57+
static const mp_arg_t allowed_args[] = {
58+
{ MP_QSTR_dither, MP_ARG_KW_ONLY | MP_ARG_BOOL, {.u_bool = false} },
59+
};
60+
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
61+
mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
5562

5663
displayio_colorconverter_t *self = m_new_obj(displayio_colorconverter_t);
5764
self->base.type = &displayio_colorconverter_type;
58-
common_hal_displayio_colorconverter_construct(self);
65+
66+
common_hal_displayio_colorconverter_construct(self, args[ARG_dither].u_bool);
5967

6068
return MP_OBJ_FROM_PTR(self);
6169
}
@@ -79,8 +87,36 @@ STATIC mp_obj_t displayio_colorconverter_obj_convert(mp_obj_t self_in, mp_obj_t
7987
}
8088
MP_DEFINE_CONST_FUN_OBJ_2(displayio_colorconverter_convert_obj, displayio_colorconverter_obj_convert);
8189

90+
//| .. attribute:: dither
91+
//|
92+
//| When true the color converter dithers the output by adding random noise when
93+
//| truncating to display bitdepth
94+
//|
95+
STATIC mp_obj_t displayio_colorconverter_obj_get_dither(mp_obj_t self_in) {
96+
displayio_colorconverter_t *self = MP_OBJ_TO_PTR(self_in);
97+
return mp_obj_new_bool(common_hal_displayio_colorconverter_get_dither(self));
98+
}
99+
MP_DEFINE_CONST_FUN_OBJ_1(displayio_colorconverter_get_dither_obj, displayio_colorconverter_obj_get_dither);
100+
101+
STATIC mp_obj_t displayio_colorconverter_obj_set_dither(mp_obj_t self_in, mp_obj_t dither) {
102+
displayio_colorconverter_t *self = MP_OBJ_TO_PTR(self_in);
103+
104+
common_hal_displayio_colorconverter_set_dither(self, mp_obj_is_true(dither));
105+
106+
return mp_const_none;
107+
}
108+
MP_DEFINE_CONST_FUN_OBJ_2(displayio_colorconverter_set_dither_obj, displayio_colorconverter_obj_set_dither);
109+
110+
const mp_obj_property_t displayio_colorconverter_dither_obj = {
111+
.base.type = &mp_type_property,
112+
.proxy = {(mp_obj_t)&displayio_colorconverter_get_dither_obj,
113+
(mp_obj_t)&displayio_colorconverter_set_dither_obj,
114+
(mp_obj_t)&mp_const_none_obj},
115+
};
116+
82117
STATIC const mp_rom_map_elem_t displayio_colorconverter_locals_dict_table[] = {
83118
{ MP_ROM_QSTR(MP_QSTR_convert), MP_ROM_PTR(&displayio_colorconverter_convert_obj) },
119+
{ MP_ROM_QSTR(MP_QSTR_dither), MP_ROM_PTR(&displayio_colorconverter_dither_obj) },
84120
};
85121
STATIC MP_DEFINE_CONST_DICT(displayio_colorconverter_locals_dict, displayio_colorconverter_locals_dict_table);
86122

@@ -90,3 +126,4 @@ const mp_obj_type_t displayio_colorconverter_type = {
90126
.make_new = displayio_colorconverter_make_new,
91127
.locals_dict = (mp_obj_dict_t*)&displayio_colorconverter_locals_dict,
92128
};
129+

‎shared-bindings/displayio/ColorConverter.h

Lines changed: 4 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -33,7 +33,10 @@
3333

3434
extern const mp_obj_type_t displayio_colorconverter_type;
3535

36-
void common_hal_displayio_colorconverter_construct(displayio_colorconverter_t* self);
36+
void common_hal_displayio_colorconverter_construct(displayio_colorconverter_t* self, bool dither);
3737
void common_hal_displayio_colorconverter_convert(displayio_colorconverter_t *colorconverter, const _displayio_colorspace_t* colorspace, uint32_t input_color, uint32_t* output_color);
3838

39+
void common_hal_displayio_colorconverter_set_dither(displayio_colorconverter_t* self, bool dither);
40+
bool common_hal_displayio_colorconverter_get_dither(displayio_colorconverter_t* self);
41+
3942
#endif // MICROPY_INCLUDED_SHARED_BINDINGS_DISPLAYIO_COLORCONVERTER_H

‎shared-bindings/displayio/Display.c

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -346,6 +346,9 @@ const mp_obj_property_t displayio_display_auto_brightness_obj = {
346346
(mp_obj_t)&mp_const_none_obj},
347347
};
348348

349+
350+
351+
349352
//| .. attribute:: width
350353
//|
351354
//| Gets the width of the board

‎shared-bindings/displayio/Display.h

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -62,6 +62,9 @@ uint16_t common_hal_displayio_display_get_rotation(displayio_display_obj_t* self
6262
bool common_hal_displayio_display_get_auto_brightness(displayio_display_obj_t* self);
6363
void common_hal_displayio_display_set_auto_brightness(displayio_display_obj_t* self, bool auto_brightness);
6464

65+
bool common_hal_displayio_display_get_dither(displayio_display_obj_t* self);
66+
void common_hal_displayio_display_set_dither(displayio_display_obj_t* self, bool dither);
67+
6568
mp_float_t common_hal_displayio_display_get_brightness(displayio_display_obj_t* self);
6669
bool common_hal_displayio_display_set_brightness(displayio_display_obj_t* self, mp_float_t brightness);
6770

‎shared-module/displayio/ColorConverter.c

Lines changed: 80 additions & 20 deletions
Original file line numberDiff line numberDiff line change
@@ -28,7 +28,19 @@
2828

2929
#include "py/misc.h"
3030

31-
void common_hal_displayio_colorconverter_construct(displayio_colorconverter_t* self) {
31+
uint32_t displayio_colorconverter_dither_noise_1 (uint32_t n)
32+
{
33+
n = (n >> 13) ^ n;
34+
int nn = (n * (n * n * 60493 + 19990303) + 1376312589) & 0x7fffffff;
35+
return (uint32_t) (((float)nn / (1073741824.0f*2)) * 255);
36+
}
37+
38+
uint32_t displayio_colorconverter_dither_noise_2(uint32_t x, uint32_t y) {
39+
return displayio_colorconverter_dither_noise_1(x + y * 0xFFFF);
40+
}
41+
42+
void common_hal_displayio_colorconverter_construct(displayio_colorconverter_t* self, bool dither) {
43+
self->dither = dither;
3244
}
3345

3446
uint16_t displayio_colorconverter_compute_rgb565(uint32_t color_rgb888) {
@@ -96,33 +108,80 @@ void displayio_colorconverter_compute_tricolor(const _displayio_colorspace_t* co
96108
}
97109
}
98110

99-
bool displayio_colorconverter_convert(displayio_colorconverter_t *self, const _displayio_colorspace_t* colorspace, uint32_t input_color, uint32_t* output_color) {
111+
void common_hal_displayio_colorconverter_convert(displayio_colorconverter_t *self, const _displayio_colorspace_t* colorspace, uint32_t input_color, uint32_t* output_color) {
112+
displayio_input_pixel_t input_pixel;
113+
input_pixel.pixel = input_color;
114+
input_pixel.x = input_pixel.y = input_pixel.tile = input_pixel.tile_x = input_pixel.tile_y = 0;
115+
116+
displayio_output_pixel_t output_pixel;
117+
output_pixel.pixel = 0;
118+
output_pixel.opaque = false;
119+
120+
displayio_colorconverter_convert(self, colorspace, &input_pixel, &output_pixel);
121+
122+
(*output_color) = output_pixel.pixel;
123+
}
124+
125+
void common_hal_displayio_colorconverter_set_dither(displayio_colorconverter_t* self, bool dither) {
126+
self->dither = dither;
127+
}
128+
129+
bool common_hal_displayio_colorconverter_get_dither(displayio_colorconverter_t* self) {
130+
return self->dither;
131+
}
132+
133+
void displayio_colorconverter_convert(displayio_colorconverter_t *self, const _displayio_colorspace_t* colorspace, const displayio_input_pixel_t *input_pixel, displayio_output_pixel_t *output_color) {
134+
uint32_t pixel = input_pixel->pixel;
135+
136+
if (self->dither){
137+
uint8_t randr = (displayio_colorconverter_dither_noise_2(input_pixel->tile_x,input_pixel->tile_y));
138+
uint8_t randg = (displayio_colorconverter_dither_noise_2(input_pixel->tile_x+33,input_pixel->tile_y));
139+
uint8_t randb = (displayio_colorconverter_dither_noise_2(input_pixel->tile_x,input_pixel->tile_y+33));
140+
141+
uint32_t r8 = (pixel >> 16);
142+
uint32_t g8 = (pixel >> 8) & 0xff;
143+
uint32_t b8 = pixel & 0xff;
144+
145+
if (colorspace->depth == 16) {
146+
b8 = MIN(255,b8 + (randb&0x07));
147+
r8 = MIN(255,r8 + (randr&0x07));
148+
g8 = MIN(255,g8 + (randg&0x03));
149+
} else {
150+
int bitmask = 0xFF >> colorspace->depth;
151+
b8 = MIN(255,b8 + (randb&bitmask));
152+
r8 = MIN(255,r8 + (randr&bitmask));
153+
g8 = MIN(255,g8 + (randg&bitmask));
154+
}
155+
pixel = r8 << 16 | g8 << 8 | b8;
156+
}
157+
100158
if (colorspace->depth == 16) {
101-
*output_color = displayio_colorconverter_compute_rgb565(input_color);
102-
return true;
159+
output_color->pixel = displayio_colorconverter_compute_rgb565(pixel);
160+
output_color->opaque = true;
161+
return;
103162
} else if (colorspace->tricolor) {
104-
uint8_t luma = displayio_colorconverter_compute_luma(input_color);
105-
*output_color = luma >> (8 - colorspace->depth);
106-
if (displayio_colorconverter_compute_chroma(input_color) <= 16) {
163+
uint8_t luma = displayio_colorconverter_compute_luma(pixel);
164+
output_color->pixel = luma >> (8 - colorspace->depth);
165+
if (displayio_colorconverter_compute_chroma(pixel) <= 16) {
107166
if (!colorspace->grayscale) {
108-
*output_color = 0;
167+
output_color->pixel = 0;
109168
}
110-
return true;
169+
output_color->opaque = true;
170+
return;
111171
}
112-
uint8_t pixel_hue = displayio_colorconverter_compute_hue(input_color);
113-
displayio_colorconverter_compute_tricolor(colorspace, pixel_hue, luma, output_color);
114-
return true;
115-
} else if (colorspace->grayscale && colorspace->depth <= 8) {
116-
uint8_t luma = displayio_colorconverter_compute_luma(input_color);
117-
*output_color = luma >> (8 - colorspace->depth);
118-
return true;
172+
uint8_t pixel_hue = displayio_colorconverter_compute_hue(pixel);
173+
displayio_colorconverter_compute_tricolor(colorspace, pixel_hue, luma, &output_color->pixel);
174+
return;
175+
} else if (colorspace->grayscale && colorspace->depth <= 8) {
176+
uint8_t luma = displayio_colorconverter_compute_luma(pixel);
177+
output_color->pixel = luma >> (8 - colorspace->depth);
178+
output_color->opaque = true;
179+
return;
119180
}
120-
return false;
181+
output_color->opaque = false;
121182
}
122183

123-
void common_hal_displayio_colorconverter_convert(displayio_colorconverter_t *self, const _displayio_colorspace_t* colorspace, uint32_t input_color, uint32_t* output_color) {
124-
displayio_colorconverter_convert(self, colorspace, input_color, output_color);
125-
}
184+
126185

127186
// Currently no refresh logic is needed for a ColorConverter.
128187
bool displayio_colorconverter_needs_refresh(displayio_colorconverter_t *self) {
@@ -131,3 +190,4 @@ bool displayio_colorconverter_needs_refresh(displayio_colorconverter_t *self) {
131190

132191
void displayio_colorconverter_finish_refresh(displayio_colorconverter_t *self) {
133192
}
193+

‎shared-module/displayio/ColorConverter.h

Lines changed: 6 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -35,11 +35,16 @@
3535

3636
typedef struct {
3737
mp_obj_base_t base;
38+
bool dither;
3839
} displayio_colorconverter_t;
3940

4041
bool displayio_colorconverter_needs_refresh(displayio_colorconverter_t *self);
4142
void displayio_colorconverter_finish_refresh(displayio_colorconverter_t *self);
42-
bool displayio_colorconverter_convert(displayio_colorconverter_t *self, const _displayio_colorspace_t* colorspace, uint32_t input_color, uint32_t* output_color);
43+
void displayio_colorconverter_convert(displayio_colorconverter_t *self, const _displayio_colorspace_t* colorspace, const displayio_input_pixel_t *input_pixel, displayio_output_pixel_t *output_color);
44+
45+
uint32_t displayio_colorconverter_dither_noise_1 (uint32_t n);
46+
uint32_t displayio_colorconverter_dither_noise_2(uint32_t x, uint32_t y);
47+
4348
uint16_t displayio_colorconverter_compute_rgb565(uint32_t color_rgb888);
4449
uint8_t displayio_colorconverter_compute_luma(uint32_t color_rgb888);
4550
uint8_t displayio_colorconverter_compute_chroma(uint32_t color_rgb888);

‎shared-module/displayio/Palette.h

Lines changed: 15 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -41,6 +41,7 @@ typedef struct {
4141
bool tricolor;
4242
bool pixels_in_byte_share_row;
4343
bool reverse_pixels_in_byte;
44+
bool dither;
4445
} _displayio_colorspace_t;
4546

4647
typedef struct {
@@ -52,6 +53,20 @@ typedef struct {
5253
bool transparent; // This may have additional bits added later for blending.
5354
} _displayio_color_t;
5455

56+
typedef struct {
57+
uint32_t pixel;
58+
uint16_t x;
59+
uint16_t y;
60+
uint8_t tile;
61+
uint16_t tile_x;
62+
uint16_t tile_y;
63+
} displayio_input_pixel_t;
64+
65+
typedef struct {
66+
uint32_t pixel;
67+
bool opaque;
68+
} displayio_output_pixel_t;
69+
5570
typedef struct {
5671
mp_obj_base_t base;
5772
_displayio_color_t* colors;

‎shared-module/displayio/TileGrid.c

Lines changed: 29 additions & 23 deletions
Original file line numberDiff line numberDiff line change
@@ -396,12 +396,16 @@ bool displayio_tilegrid_fill_area(displayio_tilegrid_t *self, const _displayio_c
396396
}
397397

398398
uint8_t pixels_per_byte = 8 / colorspace->depth;
399-
for (int16_t y = start_y; y < end_y; y++) {
400-
int16_t row_start = start + (y - start_y + y_shift) * y_stride; // in pixels
401-
int16_t local_y = y / self->absolute_transform->scale;
402-
for (int16_t x = start_x; x < end_x; x++) {
399+
400+
displayio_input_pixel_t input_pixel;
401+
displayio_output_pixel_t output_pixel;
402+
403+
for (input_pixel.y = start_y; input_pixel.y < end_y; ++input_pixel.y) {
404+
int16_t row_start = start + (input_pixel.y - start_y + y_shift) * y_stride; // in pixels
405+
int16_t local_y = input_pixel.y / self->absolute_transform->scale;
406+
for (input_pixel.x = start_x; input_pixel.x < end_x; ++input_pixel.x) {
403407
// Compute the destination pixel in the buffer and mask based on the transformations.
404-
int16_t offset = row_start + (x - start_x + x_shift) * x_stride; // in pixels
408+
int16_t offset = row_start + (input_pixel.x - start_x + x_shift) * x_stride; // in pixels
405409

406410
// This is super useful for debugging out of range accesses. Uncomment to use.
407411
// if (offset < 0 || offset >= (int32_t) displayio_area_size(area)) {
@@ -412,41 +416,43 @@ bool displayio_tilegrid_fill_area(displayio_tilegrid_t *self, const _displayio_c
412416
if ((mask[offset / 32] & (1 << (offset % 32))) != 0) {
413417
continue;
414418
}
415-
int16_t local_x = x / self->absolute_transform->scale;
419+
int16_t local_x = input_pixel.x / self->absolute_transform->scale;
416420
uint16_t tile_location = ((local_y / self->tile_height + self->top_left_y) % self->height_in_tiles) * self->width_in_tiles + (local_x / self->tile_width + self->top_left_x) % self->width_in_tiles;
417-
uint8_t tile = tiles[tile_location];
418-
uint16_t tile_x = (tile % self->bitmap_width_in_tiles) * self->tile_width + local_x % self->tile_width;
419-
uint16_t tile_y = (tile / self->bitmap_width_in_tiles) * self->tile_height + local_y % self->tile_height;
421+
input_pixel.tile = tiles[tile_location];
422+
input_pixel.tile_x = (input_pixel.tile % self->bitmap_width_in_tiles) * self->tile_width + local_x % self->tile_width;
423+
input_pixel.tile_y = (input_pixel.tile / self->bitmap_width_in_tiles) * self->tile_height + local_y % self->tile_height;
424+
425+
//uint32_t value = 0;
426+
output_pixel.pixel = 0;
427+
input_pixel.pixel = 0;
420428

421-
uint32_t value = 0;
422429
// We always want to read bitmap pixels by row first and then transpose into the destination
423430
// buffer because most bitmaps are row associated.
424431
if (MP_OBJ_IS_TYPE(self->bitmap, &displayio_bitmap_type)) {
425-
value = common_hal_displayio_bitmap_get_pixel(self->bitmap, tile_x, tile_y);
432+
input_pixel.pixel = common_hal_displayio_bitmap_get_pixel(self->bitmap, input_pixel.tile_x, input_pixel.tile_y);
426433
} else if (MP_OBJ_IS_TYPE(self->bitmap, &displayio_shape_type)) {
427-
value = common_hal_displayio_shape_get_pixel(self->bitmap, tile_x, tile_y);
434+
input_pixel.pixel = common_hal_displayio_shape_get_pixel(self->bitmap, input_pixel.tile_x, input_pixel.tile_y);
428435
} else if (MP_OBJ_IS_TYPE(self->bitmap, &displayio_ondiskbitmap_type)) {
429-
value = common_hal_displayio_ondiskbitmap_get_pixel(self->bitmap, tile_x, tile_y);
436+
input_pixel.pixel = common_hal_displayio_ondiskbitmap_get_pixel(self->bitmap, input_pixel.tile_x, input_pixel.tile_y);
430437
}
431-
432-
uint32_t pixel;
433-
bool opaque = true;
438+
439+
output_pixel.opaque = true;
434440
if (self->pixel_shader == mp_const_none) {
435-
pixel = value;
441+
output_pixel.pixel = input_pixel.pixel;
436442
} else if (MP_OBJ_IS_TYPE(self->pixel_shader, &displayio_palette_type)) {
437-
opaque = displayio_palette_get_color(self->pixel_shader, colorspace, value, &pixel);
443+
output_pixel.opaque = displayio_palette_get_color(self->pixel_shader, colorspace, input_pixel.pixel, &output_pixel.pixel);
438444
} else if (MP_OBJ_IS_TYPE(self->pixel_shader, &displayio_colorconverter_type)) {
439-
opaque = displayio_colorconverter_convert(self->pixel_shader, colorspace, value, &pixel);
445+
displayio_colorconverter_convert(self->pixel_shader, colorspace, &input_pixel, &output_pixel);
440446
}
441-
if (!opaque) {
447+
if (!output_pixel.opaque) {
442448
// A pixel is transparent so we haven't fully covered the area ourselves.
443449
full_coverage = false;
444450
} else {
445451
mask[offset / 32] |= 1 << (offset % 32);
446452
if (colorspace->depth == 16) {
447-
*(((uint16_t*) buffer) + offset) = pixel;
453+
*(((uint16_t*) buffer) + offset) = output_pixel.pixel;
448454
} else if (colorspace->depth == 8) {
449-
*(((uint8_t*) buffer) + offset) = pixel;
455+
*(((uint8_t*) buffer) + offset) = output_pixel.pixel;
450456
} else if (colorspace->depth < 8) {
451457
// Reorder the offsets to pack multiple rows into a byte (meaning they share a column).
452458
if (!colorspace->pixels_in_byte_share_row) {
@@ -465,7 +471,7 @@ bool displayio_tilegrid_fill_area(displayio_tilegrid_t *self, const _displayio_c
465471
// Reverse the shift by subtracting it from the leftmost shift.
466472
shift = (pixels_per_byte - 1) * colorspace->depth - shift;
467473
}
468-
((uint8_t*)buffer)[offset / pixels_per_byte] |= pixel << shift;
474+
((uint8_t*)buffer)[offset / pixels_per_byte] |= output_pixel.pixel << shift;
469475
}
470476
}
471477
}

‎shared-module/displayio/display_core.c

Lines changed: 9 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -49,6 +49,7 @@ void displayio_display_core_construct(displayio_display_core_t* self,
4949
self->colorspace.pixels_in_byte_share_row = pixels_in_byte_share_row;
5050
self->colorspace.bytes_per_cell = bytes_per_cell;
5151
self->colorspace.reverse_pixels_in_byte = reverse_pixels_in_byte;
52+
self->colorspace.dither = false;
5253
self->current_group = NULL;
5354
self->colstart = colstart;
5455
self->rowstart = rowstart;
@@ -172,6 +173,14 @@ uint16_t displayio_display_core_get_height(displayio_display_core_t* self){
172173
return self->height;
173174
}
174175

176+
void displayio_display_core_set_dither(displayio_display_core_t* self, bool dither){
177+
self->colorspace.dither = dither;
178+
}
179+
180+
bool displayio_display_core_get_dither(displayio_display_core_t* self){
181+
return self->colorspace.dither;
182+
}
183+
175184
bool displayio_display_core_bus_free(displayio_display_core_t *self) {
176185
return self->bus_free(self->bus);
177186
}

0 commit comments

Comments
 (0)