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display: fix SDL display format handling

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Switch SDL buffers from SDL_PIXELFORMAT_ARGB8888 to
SDL_PIXELFORMAT_BGRA32. BGRA32 is platform endianness independent
description, defined as below:

	Byte 0   Byte 1   Byte 2   Byte 3
	7......0 15.....8 23....16 31....24
	Bbbbbbbb Gggggggg Rrrrrrrr Aaaaaaaa

The driver is then updated in order to ensure that all buffers,
given via a PIXEL_FORMAT_ described format are properly converted
into the SDL_PIXELFORMAT_BGRA32. At the same time endianness
conversion code is also added in order to avoid taking assumption
that the running platform is little-endian and ensure that data
are properly read as expected.

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
This commit is contained in:
Alain Volmat
2025-12-21 21:06:17 +01:00
committed by Fabio Baltieri
parent b39b8bc94c
commit 5b5cdecb97
2 changed files with 156 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files

184
drivers/display/display_sdl.c
View File

@@ -212,6 +212,15 @@ static int sdl_display_init(const struct device *dev)
return 0;
}
/*
* Convert from Byte 0 Byte 1 Byte 2 Byte 3
* 7......0 15.....8 23....16 31....24
* PIXEL_FORMAT_ARGB_8888 Bbbbbbbb Gggggggg Rrrrrrrr Aaaaaaaa
* into
* SDL_PIXELFORMAT_BGRA32 Bbbbbbbb Gggggggg Rrrrrrrr Aaaaaaaa
*
* Hence, simple copy is enough
*/
static void sdl_display_write_argb8888(void *disp_buf,
const struct display_buffer_descriptor *desc, const void *buf)
{
@@ -221,6 +230,13 @@ static void sdl_display_write_argb8888(void *disp_buf,
memcpy(disp_buf, buf, desc->pitch * 4U * desc->height);
}
/*
* Convert from Byte 0 Byte 1 Byte 2 Byte 3
* 7......0 15.....8 23....16 31....24
* PIXEL_FORMAT_RGB_888 Bbbbbbbb Gggggggg Rrrrrrrr Bbbbbbbb
* into
* SDL_PIXELFORMAT_BGRA32 Bbbbbbbb Gggggggg Rrrrrrrr Ffffffff
*/
static void sdl_display_write_rgb888(uint8_t *disp_buf,
const struct display_buffer_descriptor *desc, const void *buf)
{
@@ -236,15 +252,24 @@ static void sdl_display_write_rgb888(uint8_t *disp_buf,
for (w_idx = 0U; w_idx < desc->width; ++w_idx) {
byte_ptr = (const uint8_t *)buf +
((h_idx * desc->pitch) + w_idx) * 3U;
pixel = *byte_ptr << 16;
pixel |= *(byte_ptr + 1) << 8;
pixel |= *(byte_ptr + 2);
*((uint32_t *)disp_buf) = pixel | 0xFF000000;
pixel = *(byte_ptr + 2) << 16; /* R */
pixel |= *(byte_ptr + 1) << 8; /* G */
pixel |= *byte_ptr; /* B */
*((uint32_t *)disp_buf) = sys_cpu_to_le32(pixel | 0xFF000000);
disp_buf += 4;
}
}
}
/*
* Convert from Byte 0 Byte 1 Byte 2 Byte 3
* 7......0 15.....8 23....16 31....24
* PIXEL_FORMAT_AL_88 Gggggggg Aaaaaaaa Gggggggg Aaaaaaaa
* into
* SDL_PIXELFORMAT_BGRA32 Bbbbbbbb Gggggggg Rrrrrrrr Aaaaaaaa
*
* G value is applied to all R/G/B value for BGRA32
*/
static void sdl_display_write_al88(uint8_t *disp_buf,
const struct display_buffer_descriptor *desc, const void *buf)
{
@@ -260,16 +285,23 @@ static void sdl_display_write_al88(uint8_t *disp_buf,
for (w_idx = 0U; w_idx < desc->width; ++w_idx) {
byte_ptr = (const uint8_t *)buf +
((h_idx * desc->pitch) + w_idx) * 2U;
pixel = *(byte_ptr + 1) << 24;
pixel |= *(byte_ptr) << 16;
pixel |= *(byte_ptr) << 8;
pixel |= *(byte_ptr);
*((uint32_t *)disp_buf) = pixel;
pixel = *(byte_ptr + 1) << 24; /* A */
pixel |= *(byte_ptr) << 16; /* R */
pixel |= *(byte_ptr) << 8; /* G */
pixel |= *(byte_ptr); /* B */
*((uint32_t *)disp_buf) = sys_cpu_to_le32(pixel);
disp_buf += 4;
}
}
}
/*
* Convert from Byte 0 Byte 1 Byte 2 Byte 3
* 7......0 15.....8 23....16 31....24
* PIXEL_FORMAT_RGB_565 gggBbbbb RrrrrGgg gggBbbbb RrrrrGgg
* into
* SDL_PIXELFORMAT_BGRA32 Bbbbbbbb Gggggggg Rrrrrrrr Ffffffff
*/
static void sdl_display_write_rgb565(uint8_t *disp_buf,
const struct display_buffer_descriptor *desc, const void *buf)
{
@@ -286,16 +318,23 @@ static void sdl_display_write_rgb565(uint8_t *disp_buf,
for (w_idx = 0U; w_idx < desc->width; ++w_idx) {
pix_ptr = (const uint16_t *)buf +
((h_idx * desc->pitch) + w_idx);
rgb565 = sys_be16_to_cpu(*pix_ptr);
pixel = (((rgb565 >> 11) & 0x1F) * 255 / 31) << 16;
pixel |= (((rgb565 >> 5) & 0x3F) * 255 / 63) << 8;
pixel |= (rgb565 & 0x1F) * 255 / 31;
*((uint32_t *)disp_buf) = pixel | 0xFF000000;
rgb565 = sys_le16_to_cpu(*pix_ptr);
pixel = (((rgb565 >> 11) & 0x1F) * 255 / 31) << 16; /* R */
pixel |= (((rgb565 >> 5) & 0x3F) * 255 / 63) << 8; /* G */
pixel |= (rgb565 & 0x1F) * 255 / 31; /* B */
*((uint32_t *)disp_buf) = sys_cpu_to_le32(pixel | 0xFF000000);
disp_buf += 4;
}
}
}
/*
* Convert from Byte 0 Byte 1 Byte 2 Byte 3
* 7......0 15.....8 23....16 31....24
* PIXEL_FORMAT_RGB_565X RrrrrGgg gggBbbbb RrrrrGgg gggBbbbb
* into
* SDL_PIXELFORMAT_BGRA32 Bbbbbbbb Gggggggg Rrrrrrrr Ffffffff
*/
static void sdl_display_write_rgb565x(uint8_t *disp_buf,
const struct display_buffer_descriptor *desc, const void *buf)
{
@@ -303,6 +342,7 @@ static void sdl_display_write_rgb565x(uint8_t *disp_buf,
uint32_t h_idx;
uint32_t pixel;
const uint16_t *pix_ptr;
uint16_t rgb565;
__ASSERT((desc->pitch * 2U * desc->height) <= desc->buf_size,
"Input buffer too small");
@@ -311,15 +351,27 @@ static void sdl_display_write_rgb565x(uint8_t *disp_buf,
for (w_idx = 0U; w_idx < desc->width; ++w_idx) {
pix_ptr = (const uint16_t *)buf +
((h_idx * desc->pitch) + w_idx);
pixel = (((*pix_ptr >> 11) & 0x1F) * 255 / 31) << 16;
pixel |= (((*pix_ptr >> 5) & 0x3F) * 255 / 63) << 8;
pixel |= (*pix_ptr & 0x1F) * 255 / 31;
*((uint32_t *)disp_buf) = pixel | 0xFF000000;
/*
* Perform be16_to_cpu here in order to swap it so that handling
* is same as for rgb565
*/
rgb565 = sys_be16_to_cpu(*pix_ptr);
pixel = (((rgb565 >> 11) & 0x1F) * 255 / 31) << 16; /* R */
pixel |= (((rgb565 >> 5) & 0x3F) * 255 / 63) << 8; /* G */
pixel |= (rgb565 & 0x1F) * 255 / 31; /* B */
*((uint32_t *)disp_buf) = sys_cpu_to_le32(pixel | 0xFF000000);
disp_buf += 4;
}
}
}
/*
* Convert from Byte 0 Byte 1 Byte 2 Byte 3
* 7......0 15.....8 23....16 31....24
* PIXEL_FORMAT_MONO(01/10) MMMMMMMM MMMMMMMM MMMMMMMM MMMMMMMM
* into
* SDL_PIXELFORMAT_BGRA32 Bbbbbbbb Gggggggg Rrrrrrrr Ffffffff
*/
static void sdl_display_write_mono(uint8_t *disp_buf, const struct display_buffer_descriptor *desc,
const void *buf, const bool one_is_black)
{
@@ -343,12 +395,22 @@ static void sdl_display_write_mono(uint8_t *disp_buf, const struct display_buffe
pixel = !!(*byte_ptr & mono_pixel_order(w_idx % 8U));
}
*((uint32_t *)disp_buf) = (pixel ? pixel_on : ~pixel_on) | 0xFF000000;
*((uint32_t *)disp_buf) =
sys_cpu_to_le32((pixel ? pixel_on : ~pixel_on) | 0xFF000000);
disp_buf += 4;
}
}
}
/*
* Convert from Byte 0 Byte 1 Byte 2 Byte 3
* 7......0 15.....8 23....16 31....24
* PIXEL_FORMAT_L_8 Gggggggg Gggggggg Gggggggg Gggggggg
* into
* SDL_PIXELFORMAT_BGRA32 Bbbbbbbb Gggggggg Rrrrrrrr Ffffffff
*
* G value is applied to all R/G/B value for BGRA32
*/
static void sdl_display_write_l8(uint8_t *disp_buf, const struct display_buffer_descriptor *desc,
const void *buf)
{
@@ -362,8 +424,10 @@ static void sdl_display_write_l8(uint8_t *disp_buf, const struct display_buffer_
for (h_idx = 0U; h_idx < desc->height; ++h_idx) {
for (w_idx = 0U; w_idx < desc->width; ++w_idx) {
byte_ptr = (const uint8_t *)buf + ((h_idx * desc->pitch) + w_idx);
pixel = *byte_ptr;
*((uint32_t *)disp_buf) = pixel | (pixel << 8) | (pixel << 16) | 0xFF000000;
pixel = *byte_ptr << 16; /* R */
pixel |= *byte_ptr << 8; /* G */
pixel |= *byte_ptr; /* B */
*((uint32_t *)disp_buf) = sys_cpu_to_le32(pixel | 0xFF000000);
disp_buf += 4;
}
}
@@ -435,6 +499,15 @@ static int sdl_display_write(const struct device *dev, const uint16_t x,
return 0;
}
/*
* Convert from Byte 0 Byte 1 Byte 2 Byte 3
* 7......0 15.....8 23....16 31....24
* SDL_PIXELFORMAT_BGRA32 Bbbbbbbb Gggggggg Rrrrrrrr Aaaaaaaa
* into
* PIXEL_FORMAT_ARGB_8888 Bbbbbbbb Gggggggg Rrrrrrrr Aaaaaaaa
*
* Hence, simple copy is enough
*/
static void sdl_display_read_argb8888(const uint8_t *read_buf,
const struct display_buffer_descriptor *desc, void *buf)
{
@@ -443,6 +516,13 @@ static void sdl_display_read_argb8888(const uint8_t *read_buf,
memcpy(buf, read_buf, desc->pitch * 4U * desc->height);
}
/*
* Convert from Byte 0 Byte 1 Byte 2 Byte 3
* 7......0 15.....8 23....16 31....24
* SDL_PIXELFORMAT_BGRA32 Bbbbbbbb Gggggggg Rrrrrrrr Ffffffff
* into
* PIXEL_FORMAT_RGB_888 Bbbbbbbb Gggggggg Rrrrrrrr Bbbbbbbb
*/
static void sdl_display_read_rgb888(const uint8_t *read_buf,
const struct display_buffer_descriptor *desc, void *buf)
{
@@ -458,16 +538,24 @@ static void sdl_display_read_rgb888(const uint8_t *read_buf,
for (w_idx = 0U; w_idx < desc->width; ++w_idx) {
pix_ptr = (const uint32_t *)read_buf + ((h_idx * desc->pitch) + w_idx);
*buf8 = (*pix_ptr & 0xFF0000) >> 16;
pix_ptr = sys_le32_to_cpu(pix_ptr);
*buf8 = (*pix_ptr & 0xFF); /* B */
buf8 += 1;
*buf8 = (*pix_ptr & 0xFF00) >> 8;
*buf8 = (*pix_ptr & 0xFF00) >> 8; /* G */
buf8 += 1;
*buf8 = (*pix_ptr & 0xFF);
*buf8 = (*pix_ptr & 0xFF0000) >> 16; /* R */
buf8 += 1;
}
}
}
/*
* Convert from Byte 0 Byte 1 Byte 2 Byte 3
* 7......0 15.....8 23....16 31....24
* SDL_PIXELFORMAT_BGRA32 Bbbbbbbb Gggggggg Rrrrrrrr Ffffffff
* into
* PIXEL_FORMAT_RGB_565 gggBbbbb RrrrrGgg gggBbbbb RrrrrGgg
*/
static void sdl_display_read_rgb565(const uint8_t *read_buf,
const struct display_buffer_descriptor *desc, void *buf)
{
@@ -484,15 +572,23 @@ static void sdl_display_read_rgb565(const uint8_t *read_buf,
for (w_idx = 0U; w_idx < desc->width; ++w_idx) {
pix_ptr = (const uint32_t *)read_buf + ((h_idx * desc->pitch) + w_idx);
pixel = (*pix_ptr & 0xF80000) >> 8;
pixel |= (*pix_ptr & 0x00FC00) >> 5;
pixel |= (*pix_ptr & 0x0000F8) >> 3;
*buf16 = sys_be16_to_cpu(pixel);
pix_ptr = sys_le32_to_cpu(pix_ptr);
pixel = (*pix_ptr & 0xF80000) >> 8; /* R */
pixel |= (*pix_ptr & 0x00FC00) >> 5; /* G */
pixel |= (*pix_ptr & 0x0000F8) >> 3; /* B */
*buf16 = sys_le16_to_cpu(pixel);
buf16 += 1;
}
}
}
/*
* Convert from Byte 0 Byte 1 Byte 2 Byte 3
* 7......0 15.....8 23....16 31....24
* SDL_PIXELFORMAT_BGRA32 Bbbbbbbb Gggggggg Rrrrrrrr Ffffffff
* into
* PIXEL_FORMAT_RGB_565X RrrrrGgg gggBbbbb RrrrrGgg gggBbbbb
*/
static void sdl_display_read_rgb565x(const uint8_t *read_buf,
const struct display_buffer_descriptor *desc, void *buf)
{
@@ -509,15 +605,27 @@ static void sdl_display_read_rgb565x(const uint8_t *read_buf,
for (w_idx = 0U; w_idx < desc->width; ++w_idx) {
pix_ptr = (const uint32_t *)read_buf + ((h_idx * desc->pitch) + w_idx);
pixel = (*pix_ptr & 0xF80000) >> 8;
pixel |= (*pix_ptr & 0x00FC00) >> 5;
pixel |= (*pix_ptr & 0x0000F8) >> 3;
*buf16 = pixel;
pix_ptr = sys_le32_to_cpu(pix_ptr);
pixel = (*pix_ptr & 0xF80000) >> 8; /* R */
pixel |= (*pix_ptr & 0x00FC00) >> 5; /* G */
pixel |= (*pix_ptr & 0x0000F8) >> 3; /* B */
/*
* Perform cpu_to_be16 here in order to swap it so that handling
* is same as for rgb565
*/
*buf16 = sys_cpu_to_be16(pixel);
buf16 += 1;
}
}
}
/*
* Convert from Byte 0 Byte 1 Byte 2 Byte 3
* 7......0 15.....8 23....16 31....24
* SDL_PIXELFORMAT_BGRA32 Bbbbbbbb Gggggggg Rrrrrrrr Ffffffff
* into
* PIXEL_FORMAT_MONO(01/10) MMMMMMMM MMMMMMMM MMMMMMMM MMMMMMMM
*/
static void sdl_display_read_mono(const uint8_t *read_buf,
const struct display_buffer_descriptor *desc, void *buf,
const bool one_is_black)
@@ -534,6 +642,7 @@ static void sdl_display_read_mono(const uint8_t *read_buf,
for (h_idx = 0U; h_idx < desc->height; ++h_idx) {
for (w_idx = 0U; w_idx < desc->width; ++w_idx) {
pix_ptr = (const uint32_t *)read_buf + h_idx * desc->pitch + w_idx;
pix_ptr = sys_cpu_to_le32(pix_ptr);
buf8 = buf;
if (IS_ENABLED(CONFIG_SDL_DISPLAY_MONO_VTILED)) {
@@ -553,6 +662,15 @@ static void sdl_display_read_mono(const uint8_t *read_buf,
}
}
/*
* Convert from Byte 0 Byte 1 Byte 2 Byte 3
* 7......0 15.....8 23....16 31....24
* SDL_PIXELFORMAT_BGRA32 Bbbbbbbb Gggggggg Rrrrrrrr Ffffffff
* into
* PIXEL_FORMAT_L_8 Gggggggg Gggggggg Gggggggg Gggggggg
*
* G value is taken from the B component of SDL_PIXELFORMAT_BGRA32
*/
static void sdl_display_read_l8(const uint8_t *read_buf,
const struct display_buffer_descriptor *desc, void *buf)
{
@@ -568,6 +686,7 @@ static void sdl_display_read_l8(const uint8_t *read_buf,
for (w_idx = 0U; w_idx < desc->width; ++w_idx) {
pix_ptr = (const uint32_t *)read_buf + ((h_idx * desc->pitch) + w_idx);
pix_ptr = sys_le32_to_cpu(pix_ptr);
*buf8 = *pix_ptr & 0xFF;
buf8 += 1;
}
@@ -589,6 +708,7 @@ static void sdl_display_read_al88(const uint8_t *read_buf,
for (w_idx = 0U; w_idx < desc->width; ++w_idx) {
pix_ptr = (const uint32_t *)read_buf + ((h_idx * desc->pitch) + w_idx);
pix_ptr = sys_le32_to_cpu(pix_ptr);
*buf8 = (*pix_ptr & 0xFF);
buf8 += 1;
*buf8 = (*pix_ptr & 0xFF000000) >> 24;

8
drivers/display/display_sdl_bottom.c
View File

@@ -103,7 +103,7 @@ int sdl_display_init_bottom(struct sdl_display_init_params *params)
SDL_RenderSetLogicalSize(*params->renderer, params->width, params->height);
*params->texture =
SDL_CreateTexture(*params->renderer, SDL_PIXELFORMAT_ARGB8888,
SDL_CreateTexture(*params->renderer, SDL_PIXELFORMAT_BGRA32,
SDL_TEXTUREACCESS_STATIC, params->width, params->height);
if (*params->texture == NULL) {
nsi_print_warning("Failed to create SDL texture: %s", SDL_GetError());
@@ -112,7 +112,7 @@ int sdl_display_init_bottom(struct sdl_display_init_params *params)
SDL_SetTextureBlendMode(*params->texture, SDL_BLENDMODE_BLEND);
*params->read_texture =
SDL_CreateTexture(*params->renderer, SDL_PIXELFORMAT_ARGB8888,
SDL_CreateTexture(*params->renderer, SDL_PIXELFORMAT_BGRA32,
SDL_TEXTUREACCESS_TARGET, params->width, params->height);
if (*params->read_texture == NULL) {
nsi_print_warning("Failed to create SDL texture for read: %s", SDL_GetError());
@@ -120,7 +120,7 @@ int sdl_display_init_bottom(struct sdl_display_init_params *params)
}
*params->background_texture =
SDL_CreateTexture(*params->renderer, SDL_PIXELFORMAT_ARGB8888,
SDL_CreateTexture(*params->renderer, SDL_PIXELFORMAT_BGRA32,
SDL_TEXTUREACCESS_STREAMING, params->width, params->height);
if (*params->background_texture == NULL) {
nsi_print_warning("Failed to create SDL texture: %s", SDL_GetError());
@@ -234,7 +234,7 @@ int sdl_display_read_bottom(const struct sdl_display_read_params *params)
SDL_RenderClear(params->renderer);
SDL_RenderCopy(params->renderer, params->texture, NULL, NULL);
SDL_RenderReadPixels(params->renderer, &rect, SDL_PIXELFORMAT_ARGB8888, params->buf,
SDL_RenderReadPixels(params->renderer, &rect, SDL_PIXELFORMAT_BGRA32, params->buf,
params->width * 4);
SDL_SetTextureBlendMode(params->texture, SDL_BLENDMODE_BLEND);