From 37d495fca3506f63e36ff49e8d67efc136e5079e Mon Sep 17 00:00:00 2001
From: Henrik Hautakoski <henrik.hautakoski@gmail.com>
Date: Thu, 22 Oct 2020 17:07:42 +0200
Subject: [PATCH] Adding source/Graphics/Image/IcoFormat

---
 engine.build.lua                    |  1 +
 source/Graphics/Image/IcoFormat.cpp | 76 +++++++++++++++++++++++++++++
 source/Graphics/Image/IcoFormat.h   | 19 ++++++++
 3 files changed, 96 insertions(+)
 create mode 100644 source/Graphics/Image/IcoFormat.cpp
 create mode 100644 source/Graphics/Image/IcoFormat.h

diff --git a/engine.build.lua b/engine.build.lua
index 35a8e2a..64a7ecb 100644
--- a/engine.build.lua
+++ b/engine.build.lua
@@ -99,6 +99,7 @@ local graphics_module = Module("source/Graphics", {
 	-- Image
 	"Image.cpp",
 	"ImageLoader.cpp",
+	"Image/IcoFormat.cpp",
 
 	"OpenGL.cpp",
 	"GL/glad.c",
diff --git a/source/Graphics/Image/IcoFormat.cpp b/source/Graphics/Image/IcoFormat.cpp
new file mode 100644
index 0000000..721a106
--- /dev/null
+++ b/source/Graphics/Image/IcoFormat.cpp
@@ -0,0 +1,76 @@
+
+#include "IcoFormat.h"
+#include <Spectre/System/ByteOrder.h>
+#include <Spectre/Graphics/Image.h>
+#include <Spectre/System/Log.h>
+
+#include "Format/ico.h"
+
+namespace sp {
+namespace image {
+
+ICONDIRENTRY* findLargestImage(ICONDIRENTRY *ent, uint16_t size) {
+
+	uint32_t idx = 0, lgsz = 0, sz;
+
+	for (int i = 0; i < size; i++) {
+		sz = ent[i].width * ent[i].height;
+		if (sz > lgsz) {
+			lgsz = sz;
+			idx = i;
+		}
+	}
+	return ent + idx;
+}
+
+bool IcoFormat::decode(Image& img, const unsigned char *data, unsigned size)
+{
+	uint8_t *pixels;
+	PixelFormat format;
+	ICONDIRENTRY *ent;
+	ICONDIRENTRY *largest;
+	uint16_t type;
+	uint16_t num_ent;
+
+	type 		= system::ltoh16(data + 2);
+	num_ent 	= system::ltoh16(data + 4);
+
+	// Type: 1 = ICO, 2 = CUR
+	if (type != 0x0001 || num_ent < 1) {
+		return false;
+	}
+
+	// Allocate ICONDIRENT for all images in the file.
+	ent = (ICONDIRENTRY *) malloc(sizeof(ICONDIRENTRY) * num_ent);
+	if (!ent) {
+		return false;
+	}
+
+	for (int i = 0; i < num_ent; i++) {
+		unsigned int p = 6 + (i * ICONDIRENTRY_SIZE);
+		ent[i].width 		 = data[p + 0];
+		ent[i].height 		 = data[p + 1];
+		ent[i].num_colors 	 = data[p + 2];
+		ent[i].color_planes  = data[p + 4];
+		ent[i].bpp			 = data[p + 6];
+		ent[i].size		 	 = system::ltoh32(data + p + 8);
+		ent[i].offset		 = system::ltoh32(data + p + 12);
+	}
+
+	// Find Largest image
+	largest = findLargestImage(ent, num_ent);
+
+	if (largest->bpp == 32) {
+		format = PixelFormat::PF_32BGRA;
+	} else {
+		format = PixelFormat::PF_32BGR;
+	}
+
+	// NOTE: plus 40 bytes here to skip over the DIB header.
+	img.create(largest->width, largest->height, data + largest->offset + 40, format);
+	free(ent);
+
+	return true;
+}
+
+}} // namespace sp::image
diff --git a/source/Graphics/Image/IcoFormat.h b/source/Graphics/Image/IcoFormat.h
new file mode 100644
index 0000000..bd8c729
--- /dev/null
+++ b/source/Graphics/Image/IcoFormat.h
@@ -0,0 +1,19 @@
+
+#ifndef SPECTRE_GRAPHICS_IMAGE_ICOFORMAT_H
+#define SPECTRE_GRAPHICS_IMAGE_ICOFORMAT_H
+
+#include <Spectre/Graphics/Image.h>
+
+namespace sp {
+namespace image {
+
+class IcoFormat
+{
+public :
+
+	bool decode(Image& img, const unsigned char *data, unsigned size);
+};
+
+}} // namespace sp::image
+
+#endif /* SPECTRE_GRAPHICS_IMAGE_ICOFORMAT_H */