1 files changed, 137 insertions, 0 deletions
diff --git a/quantum/painter/qff.c b/quantum/painter/qff.c
new file mode 100644
index 0000000000..cd6af788f9
--- /dev/null
+++ b/quantum/painter/qff.c
@@ -0,0 +1,137 @@
+// Copyright 2021 Nick Brassel (@tzarc)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+// Quantum Font File "QFF" File Format.
+// See https://docs.qmk.fm/#/quantum_painter_qff for more information.
+
+#include "qff.h"
+#include "qp_draw.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// QFF API
+
+bool qff_read_font_descriptor(qp_stream_t *stream, uint8_t *line_height, bool *has_ascii_table, uint16_t *num_unicode_glyphs, uint8_t *bpp, bool *has_palette, painter_compression_t *compression_scheme, uint32_t *total_bytes) {
+    // Seek to the start
+    qp_stream_setpos(stream, 0);
+
+    // Read and validate the font descriptor
+    qff_font_descriptor_v1_t font_descriptor;
+    if (qp_stream_read(&font_descriptor, sizeof(qff_font_descriptor_v1_t), 1, stream) != 1) {
+        qp_dprintf("Failed to read font_descriptor, expected length was not %d\n", (int)sizeof(qff_font_descriptor_v1_t));
+        return false;
+    }
+
+    // Make sure this block is valid
+    if (!qgf_validate_block_header(&font_descriptor.header, QFF_FONT_DESCRIPTOR_TYPEID, (sizeof(qff_font_descriptor_v1_t) - sizeof(qgf_block_header_v1_t)))) {
+        return false;
+    }
+
+    // Make sure the magic and version are correct
+    if (font_descriptor.magic != QFF_MAGIC || font_descriptor.qff_version != 0x01) {
+        qp_dprintf("Failed to validate font_descriptor, expected magic 0x%06X was 0x%06X, expected version = 0x%02X was 0x%02X\n", (int)QFF_MAGIC, (int)font_descriptor.magic, (int)0x01, (int)font_descriptor.qff_version);
+        return false;
+    }
+
+    // Make sure the file length is valid
+    if (font_descriptor.neg_total_file_size != ~font_descriptor.total_file_size) {
+        qp_dprintf("Failed to validate font_descriptor, expected negated length 0x%08X was 0x%08X\n", (int)(~font_descriptor.total_file_size), (int)font_descriptor.neg_total_file_size);
+        return false;
+    }
+
+    // Copy out the required info
+    if (line_height) {
+        *line_height = font_descriptor.line_height;
+    }
+    if (has_ascii_table) {
+        *has_ascii_table = font_descriptor.has_ascii_table;
+    }
+    if (num_unicode_glyphs) {
+        *num_unicode_glyphs = font_descriptor.num_unicode_glyphs;
+    }
+    if (bpp || has_palette) {
+        if (!qgf_parse_format(font_descriptor.format, bpp, has_palette)) {
+            return false;
+        }
+    }
+    if (compression_scheme) {
+        *compression_scheme = font_descriptor.compression_scheme;
+    }
+    if (total_bytes) {
+        *total_bytes = font_descriptor.total_file_size;
+    }
+
+    return true;
+}
+
+static bool qff_validate_ascii_descriptor(qp_stream_t *stream) {
+    // Read the raw descriptor
+    qff_ascii_glyph_table_v1_t ascii_descriptor;
+    if (qp_stream_read(&ascii_descriptor, sizeof(qff_ascii_glyph_table_v1_t), 1, stream) != 1) {
+        qp_dprintf("Failed to read ascii_descriptor, expected length was not %d\n", (int)sizeof(qff_ascii_glyph_table_v1_t));
+        return false;
+    }
+
+    // Make sure this block is valid
+    if (!qgf_validate_block_header(&ascii_descriptor.header, QFF_ASCII_GLYPH_DESCRIPTOR_TYPEID, (sizeof(qff_ascii_glyph_table_v1_t) - sizeof(qgf_block_header_v1_t)))) {
+        return false;
+    }
+
+    return true;
+}
+
+static bool qff_validate_unicode_descriptor(qp_stream_t *stream, uint16_t num_unicode_glyphs) {
+    // Read the raw descriptor
+    qff_unicode_glyph_table_v1_t unicode_descriptor;
+    if (qp_stream_read(&unicode_descriptor, sizeof(qff_unicode_glyph_table_v1_t), 1, stream) != 1) {
+        qp_dprintf("Failed to read unicode_descriptor, expected length was not %d\n", (int)sizeof(qff_unicode_glyph_table_v1_t));
+        return false;
+    }
+
+    // Make sure this block is valid
+    if (!qgf_validate_block_header(&unicode_descriptor.header, QFF_UNICODE_GLYPH_DESCRIPTOR_TYPEID, num_unicode_glyphs * 6)) {
+        return false;
+    }
+
+    // Skip the necessary amount of data to get to the next block
+    qp_stream_seek(stream, num_unicode_glyphs * sizeof(qff_unicode_glyph_v1_t), SEEK_CUR);
+
+    return true;
+}
+
+bool qff_validate_stream(qp_stream_t *stream) {
+    bool     has_ascii_table;
+    uint16_t num_unicode_glyphs;
+
+    if (!qff_read_font_descriptor(stream, NULL, &has_ascii_table, &num_unicode_glyphs, NULL, NULL, NULL, NULL)) {
+        return false;
+    }
+
+    if (has_ascii_table) {
+        if (!qff_validate_ascii_descriptor(stream)) {
+            return false;
+        }
+    }
+
+    if (num_unicode_glyphs > 0) {
+        if (!qff_validate_unicode_descriptor(stream, num_unicode_glyphs)) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+uint32_t qff_get_total_size(qp_stream_t *stream) {
+    // Get the original location
+    uint32_t oldpos = qp_stream_tell(stream);
+
+    // Read the font descriptor, grabbing the size
+    uint32_t total_size;
+    if (!qff_read_font_descriptor(stream, NULL, NULL, NULL, NULL, NULL, NULL, &total_size)) {
+        return false;
+    }
+
+    // Restore the original location
+    qp_stream_setpos(stream, oldpos);
+    return total_size;
+}