first sketch

1 files changed, 271 insertions, 0 deletions

diff --git a/drw.c b/drw.c
new file mode 100644
index 0000000..f65f330
--- /dev/null
+++ b/drw.c
@@ -0,0 +1,271 @@
+#include <sys/mman.h>
+#include <unistd.h>
+#include <math.h>
+#include <grapheme.h>
+
+#include "drw.h"
+#include "util.h"
+
+/* static function declarations */
+static Color to_color(uint32_t color);
+static uint32_t to_uint32_t(Color color);
+static void draw_bitmap(Canvas *canvas, FT_Bitmap *bitmap, unsigned x, unsigned y, uint32_t color);
+
+
+Color
+to_color(uint32_t color)
+{
+	return *(Color*)(&color);
+}
+
+
+uint32_t
+to_uint32_t(Color color)
+{
+	return *(uint32_t*)(&color);
+}
+
+
+Canvas*
+create_drw(struct wl_shm *shm, unsigned width, unsigned height)
+{
+	struct wl_shm_pool *pool;
+	Canvas *canvas;
+	int stride;
+	int fd;
+
+	canvas = malloc(sizeof(Canvas));
+	canvas->width = width;
+	canvas->height = height;
+
+	stride = width * sizeof(uint32_t);
+	canvas->size = stride * height;
+
+	fd = allocate_shm_file(canvas->size);
+	if (fd == -1) {
+		return NULL;
+	}
+
+	canvas->data = mmap(
+			NULL,
+			canvas->size,
+			PROT_READ | PROT_WRITE,
+			MAP_SHARED,
+			fd,
+			0
+		);
+
+	if (canvas->data == MAP_FAILED) {
+		close(fd);
+		return NULL;
+	}
+
+	pool = wl_shm_create_pool(
+			shm,
+			fd,
+			canvas->size
+	);
+
+	canvas->buffer = wl_shm_pool_create_buffer(
+			pool,
+			0,
+			width,
+			height,
+			stride,
+			WL_SHM_FORMAT_XRGB8888
+		);
+
+	wl_shm_pool_destroy(pool);
+	close(fd);
+
+	return canvas;
+}
+
+
+void
+free_drw(Canvas *canvas)
+{
+	munmap(canvas->data, canvas->size);
+	free(canvas);
+}
+
+
+void
+draw_point(Canvas *canvas, unsigned x, unsigned y, uint32_t color)
+{
+	if (!(x < canvas->width && y < canvas->height))
+		return;
+
+	canvas->data[x + canvas->width * y] = color;
+}
+
+
+void
+draw_rect(Canvas *canvas, unsigned x, unsigned y, unsigned width, unsigned height, uint32_t color) {
+	int py;
+	int px;
+
+	for (py = y; py < y + height; ++py) {
+		for (px = x; px < x + width; ++px) {
+			draw_point(canvas, px, py, color);
+		}
+	}
+}
+
+Font *
+create_font(const char *fontpath, unsigned size)
+{
+	FT_Error error;
+	Font * font;
+
+	font = malloc(sizeof(Font));
+
+	error = FT_Init_FreeType(&font->library);
+
+	if (error)
+		die("cannot init library");
+
+	error = FT_New_Face(font->library, fontpath, 0, &font->face);
+	if (error)
+		die("cannot open face");
+
+	error = FT_Set_Pixel_Sizes(font->face, 0, size);
+	if (error)
+		die("cannot set char size");
+
+	error = FT_Select_Charmap(font->face, ft_encoding_unicode);
+	if (error)
+		die("cannot set unicode");
+
+	return font;
+}
+
+void
+free_font(Font *font)
+{
+	FT_Done_Face(font->face);
+	FT_Done_FreeType(font->library);
+	free(font);
+}
+
+
+void
+draw_bitmap(Canvas *canvas, FT_Bitmap *bitmap, unsigned x, unsigned y, uint32_t color)
+{
+	FT_Int  i, j, p, q;
+	double strength;
+	uint32_t pixel;
+
+	Color fg = to_color(color);
+	Color bg;
+	Color c;
+
+	c.a = fg.a;
+
+	i = x;
+	p = 0;
+
+	while (p < bitmap->width) {
+		j = y;
+		q = 0;
+
+		while (q < bitmap->rows) {
+			if (i < 0 || j < 0 || i >= canvas->width || j >= canvas->height) {
+				j++;
+				q++;
+				continue;
+			}
+
+			bg = to_color(canvas->data[i + j * canvas->width]);
+			strength = bitmap->buffer[p + q * bitmap->width];
+			strength /= 255;
+
+			c.r = (strength * fg.r) + ((1 - strength) * bg.r);
+			c.g = (strength * fg.g) + ((1 - strength) * bg.g);
+			c.b = (strength * fg.b) + ((1 - strength) * bg.b);
+
+			pixel = to_uint32_t(c);
+			draw_point(canvas, i, j, pixel);
+
+			j++;
+			q++;
+		}
+
+		i++;
+		p++;
+	}
+}
+
+
+unsigned
+draw_font(Canvas *canvas, Font *font, const char *text, unsigned x, unsigned y, uint32_t color)
+{
+	FT_GlyphSlot slot;
+	FT_Error error;
+	FT_UInt glyph_index;
+	FT_UInt previous = 0;
+	uint_least32_t charcode;
+	FT_Bool has_kerning = FT_HAS_KERNING(font->face);
+	FT_Vector delta;
+
+	slot = font->face->glyph;
+
+	for (; *text;) {
+		text += grapheme_decode_utf8(text, sizeof(uint_least32_t), &charcode);
+
+		glyph_index = FT_Get_Char_Index(font->face, charcode);
+
+		if (has_kerning && previous && glyph_index) {
+			FT_Get_Kerning(font->face, previous, glyph_index, FT_KERNING_DEFAULT, &delta);
+			x += delta.x >> 6;
+		}
+
+		error = FT_Load_Glyph(font->face, glyph_index, FT_LOAD_RENDER);
+		if (error) {
+			fprintf(stderr, "warning: char not loaded, skipping...\n");
+			continue;
+		}
+
+		draw_bitmap(canvas, &slot->bitmap, x + slot->bitmap_left, y - slot->bitmap_top, color);
+
+		x += slot->advance.x >> 6;
+	}
+
+	return x;
+}
+
+unsigned
+font_width(Font *font, const char *text)
+{
+	FT_GlyphSlot slot;
+	FT_Error error;
+	FT_UInt glyph_index;
+	FT_UInt previous = 0;
+	uint_least32_t charcode;
+	FT_Bool has_kerning = FT_HAS_KERNING(font->face);
+	FT_Vector delta;
+	unsigned x = 0;
+
+	slot = font->face->glyph;
+
+	for (; *text;) {
+		text += grapheme_decode_utf8(text, sizeof(uint_least32_t), &charcode);
+
+		glyph_index = FT_Get_Char_Index(font->face, charcode);
+
+		if (has_kerning && previous && glyph_index) {
+			FT_Get_Kerning(font->face, previous, glyph_index, FT_KERNING_DEFAULT, &delta);
+			x += delta.x >> 6;
+		}
+
+		error = FT_Load_Glyph(font->face, glyph_index, FT_LOAD_RENDER);
+		if (error) {
+			fprintf(stderr, "warning: char not loaded, skipping...\n");
+			continue;
+		}
+
+		x += slot->advance.x >> 6;
+	}
+
+	return x;
+}