1 files changed, 136 insertions, 0 deletions
diff --git a/src/visualizer/grid.c b/src/visualizer/grid.c
new file mode 100644
index 0000000..5f95efc
--- /dev/null
+++ b/src/visualizer/grid.c
@@ -0,0 +1,136 @@
+#include "visualizer/grid.h"
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+static size_t glyph_bytes(unsigned char lead)
+{
+	if (lead < 0x80)
+		return 1;
+	if ((lead >> 5) == 0x6)
+		return 2;
+	if ((lead >> 4) == 0xE)
+		return 3;
+	if ((lead >> 3) == 0x1E)
+		return 4;
+
+	return 1;
+}
+
+size_t psi_utf8_count(const char *s)
+{
+	size_t count = 0;
+	while (*s)
+	{
+		s += glyph_bytes((unsigned char)*s);
+		count++;
+	}
+
+	return count;
+}
+
+struct PsiStringBuilder psi_new_string_builder(void)
+{
+	return (struct PsiStringBuilder)
+	{
+		NULL,
+		0,
+		0,
+	};
+}
+
+void psi_string_builder_append(struct PsiStringBuilder *sb, const char *s)
+{
+	size_t n = strlen(s);
+	if (sb->len + n + 1 > sb->cap)
+	{
+		size_t new_cap = sb->cap == 0 ? 256 : sb->cap * 2;
+		while (new_cap < sb->len + n + 1)
+			new_cap *= 2;
+
+		sb->data = realloc(sb->data, new_cap);
+		assert(sb->data != NULL);
+		sb->cap = new_cap;
+	}
+
+	memcpy(sb->data + sb->len, s, n + 1);
+	sb->len += n;
+}
+
+char *psi_string_builder_finish(struct PsiStringBuilder *sb)
+{
+	if (sb->data == NULL)
+		psi_string_builder_append(sb, "");
+
+	return sb->data;
+}
+
+struct PsiGlyphRow psi_new_glyph_row(size_t width)
+{
+	char (*cells)[5] = malloc(width * sizeof(*cells));
+	assert(cells != NULL || width == 0);
+
+	for (size_t i = 0; i < width; i++)
+		memcpy(cells[i], " ", 2);
+
+	return (struct PsiGlyphRow)
+	{
+		cells,
+		width,
+	};
+}
+
+void psi_free_glyph_row(struct PsiGlyphRow *row)
+{
+	free(row->cells);
+	row->cells = NULL;
+	row->width = 0;
+}
+
+void psi_glyph_row_set(struct PsiGlyphRow *row, size_t index, const char *glyph)
+{
+	if (index >= row->width)
+		return;
+
+	size_t n = glyph_bytes((unsigned char)glyph[0]);
+	memcpy(row->cells[index], glyph, n);
+	row->cells[index][n] = '\0';
+}
+
+size_t psi_glyph_row_place(struct PsiGlyphRow *row, size_t start, const char *utf8)
+{
+	size_t count = 0;
+	const char *p = utf8;
+
+	while (*p)
+	{
+		size_t n = glyph_bytes((unsigned char)*p);
+		size_t index = start + count;
+		if (index < row->width)
+		{
+			memcpy(row->cells[index], p, n);
+			row->cells[index][n] = '\0';
+		}
+
+		p += n;
+		count++;
+	}
+
+	return count;
+}
+
+void psi_glyph_row_fill_space(struct PsiGlyphRow *row, size_t from, size_t to, const char *glyph)
+{
+	for (size_t i = from; i < to && i < row->width; i++)
+		if (strcmp(row->cells[i], " ") == 0)
+			psi_glyph_row_set(row, i, glyph);
+}
+
+void psi_glyph_row_render(struct PsiGlyphRow row, struct PsiStringBuilder *sb)
+{
+	for (size_t i = 0; i < row.width; i++)
+		psi_string_builder_append(sb, row.cells[i]);
+
+	psi_string_builder_append(sb, "\n");
+}