Unpremultiply cairo surface data.

Kristian Høgsberg 16 years ago
parent d3fa34ca29
commit 1b2f4390f5
  1. 43
      flower.c
  2. 37
      pointer.c

@ -18,16 +18,48 @@
static const char gem_device[] = "/dev/dri/card0";
static const char socket_name[] = "\0wayland";
static void
unpremultiply_data(uint8_t *data, int width, int height, int stride)
{
unsigned int i, j;
uint8_t *row;
for (j = 0; j < height; j++) {
row = data + j * stride;
for (i = 0; i < width; i++) {
uint8_t *b = &row[i * 4];
uint32_t pixel;
uint8_t alpha;
memcpy (&pixel, b, sizeof (uint32_t));
alpha = (pixel & 0xff000000) >> 24;
if (alpha == 0) {
b[0] = b[1] = b[2] = b[3] = 0;
} else {
b[0] = (((pixel & 0xff0000) >> 16) * 255 + alpha / 2) / alpha;
b[1] = (((pixel & 0x00ff00) >> 8) * 255 + alpha / 2) / alpha;
b[2] = (((pixel & 0x0000ff) >> 0) * 255 + alpha / 2) / alpha;
b[3] = alpha;
}
}
}
}
static uint32_t name_cairo_surface(int fd, cairo_surface_t *surface)
{
struct drm_i915_gem_create create;
struct drm_gem_flink flink;
struct drm_i915_gem_pwrite pwrite;
int32_t width, height, stride;
void *data;
width = cairo_image_surface_get_width(surface);
height = cairo_image_surface_get_height(surface);
stride = cairo_image_surface_get_stride(surface);
data = cairo_image_surface_get_data(surface);
unpremultiply_data(data, width, height, stride);
memset(&create, 0, sizeof(create));
create.size = height * stride;
@ -40,8 +72,7 @@ static uint32_t name_cairo_surface(int fd, cairo_surface_t *surface)
pwrite.handle = create.handle;
pwrite.offset = 0;
pwrite.size = height * stride;
pwrite.data_ptr = (uint64_t) (uintptr_t)
cairo_image_surface_get_data(surface);
pwrite.data_ptr = (uint64_t) (uintptr_t) data;
if (ioctl(fd, DRM_IOCTL_I915_GEM_PWRITE, &pwrite) < 0) {
fprintf(stderr, "gem pwrite failed: %m\n");
return 0;
@ -149,7 +180,7 @@ int main(int argc, char *argv[])
{
struct wl_display *display;
struct wl_surface *surface;
const int x = 200, y = 200, width = 200, height = 200;
const int x = 512, y = 384, width = 200, height = 200;
int fd, i, ret;
uint32_t name, mask;
cairo_surface_t *s;
@ -198,13 +229,13 @@ int main(int argc, char *argv[])
wl_surface_attach(surface, name, width, height,
cairo_image_surface_get_stride(s));
i = 0;
i = ts.tv_nsec;
while (ret = poll(p, 2, -1), ret >= 0) {
if (p[1].revents & POLLIN) {
read(p[1].fd, &expires, sizeof expires);
wl_surface_map(surface,
x + cos(i / 30.0) * 200,
y + sin(i / 31.0) * 200,
x + cos(i / 31.0) * 400 - width / 2,
y + sin(i / 27.0) * 300 - height / 2,
width, height);
i++;
continue;

@ -15,16 +15,48 @@
static const char gem_device[] = "/dev/dri/card0";
static const char socket_name[] = "\0wayland";
static void
unpremultiply_data(uint8_t *data, int width, int height, int stride)
{
unsigned int i, j;
uint8_t *row;
for (j = 0; j < height; j++) {
row = data + j * stride;
for (i = 0; i < width; i++) {
uint8_t *b = &row[i * 4];
uint32_t pixel;
uint8_t alpha;
memcpy (&pixel, b, sizeof (uint32_t));
alpha = (pixel & 0xff000000) >> 24;
if (alpha == 0) {
b[0] = b[1] = b[2] = b[3] = 0;
} else {
b[0] = (((pixel & 0xff0000) >> 16) * 255 + alpha / 2) / alpha;
b[1] = (((pixel & 0x00ff00) >> 8) * 255 + alpha / 2) / alpha;
b[2] = (((pixel & 0x0000ff) >> 0) * 255 + alpha / 2) / alpha;
b[3] = alpha;
}
}
}
}
static uint32_t name_cairo_surface(int fd, cairo_surface_t *surface)
{
struct drm_i915_gem_create create;
struct drm_gem_flink flink;
struct drm_i915_gem_pwrite pwrite;
int32_t width, height, stride;
void *data;
width = cairo_image_surface_get_width(surface);
height = cairo_image_surface_get_height(surface);
stride = cairo_image_surface_get_stride(surface);
data = cairo_image_surface_get_data(surface);
unpremultiply_data(data, width, height, stride);
memset(&create, 0, sizeof(create));
create.size = height * stride;
@ -37,8 +69,7 @@ static uint32_t name_cairo_surface(int fd, cairo_surface_t *surface)
pwrite.handle = create.handle;
pwrite.offset = 0;
pwrite.size = height * stride;
pwrite.data_ptr = (uint64_t) (uintptr_t)
cairo_image_surface_get_data(surface);
pwrite.data_ptr = (uint64_t) (uintptr_t) data;
if (ioctl(fd, DRM_IOCTL_I915_GEM_PWRITE, &pwrite) < 0) {
fprintf(stderr, "gem pwrite failed: %m\n");
return 0;
@ -68,7 +99,7 @@ static uint32_t name_cairo_surface(int fd, cairo_surface_t *surface)
static void *
draw_pointer(int width, int height)
{
const int d = 2, end = 4, tx = 2, ty = 6, dx = 5, dy = 4;
const int d = 2, end = 4, tx = 2, ty = 6, dx = 4, dy = 4;
cairo_surface_t *surface;
cairo_t *cr;

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