Added Texture class

include/eos/render/utils.hpp

@@ -23,6 +23,7 @@
 #define RENDER_UTILS_HPP_
 
 #include "opencv2/core/core.hpp"
+#include "opencv2/imgproc/imgproc.hpp"
 
 namespace eos {
 	namespace render {
@@ -78,6 +79,85 @@ inline cv::Vec2f screen_to_clip_space(const cv::Vec2f& screen_coordinates, int s
 	return cv::Vec2f(x_cs, y_cs);
 };
 
+// TODO: Should go to detail:: namespace, or texturing/utils or whatever.
+unsigned int get_max_possible_mipmaps_num(unsigned int width, unsigned int height)
+{
+	unsigned int mipmapsNum = 1;
+	unsigned int size = std::max(width, height);
+
+	if (size == 1)
+		return 1;
+
+	do {
+		size >>= 1;
+		mipmapsNum++;
+	} while (size != 1);
+
+	return mipmapsNum;
+};
+
+inline bool is_power_of_two(int x)
+{
+	return !(x & (x - 1));
+};
+
+class Texture
+{
+public:
+	// Todo: This whole class needs a major overhaul and documentation.
+
+	// throws: ocv exc,  runtime_ex
+	void create_mipmapped_texture(cv::Mat image, unsigned int mipmapsNum = 0) {
+
+		this->mipmaps_num = (mipmapsNum == 0 ? get_max_possible_mipmaps_num(image.cols, image.rows) : mipmapsNum);
+		/*if (mipmapsNum == 0)
+		{
+		uchar mmn = render::utils::MatrixUtils::getMaxPossibleMipmapsNum(image.cols, image.rows);
+		this->mipmapsNum = mmn;
+		} else
+		{
+		this->mipmapsNum = mipmapsNum;
+		}*/
+
+		if (this->mipmaps_num > 1)
+		{
+			if (!is_power_of_two(image.cols) || !is_power_of_two(image.rows))
+			{
+				throw std::runtime_error("Error: Couldn't generate mipmaps, width or height not power of two.");
+			}
+		}
+		image.convertTo(image, CV_8UC4);	// Most often, the input img is CV_8UC3. Img is BGR. Add an alpha channel
+		cv::cvtColor(image, image, CV_BGR2BGRA);
+
+		int currWidth = image.cols;
+		int currHeight = image.rows;
+		for (int i = 0; i < this->mipmaps_num; i++)
+		{
+			if (i == 0) {
+				mipmaps.push_back(image);
+			}
+			else {
+				cv::Mat currMipMap(currHeight, currWidth, CV_8UC4);
+				cv::resize(mipmaps[i - 1], currMipMap, currMipMap.size());
+				mipmaps.push_back(currMipMap);
+			}
+
+			if (currWidth > 1)
+				currWidth >>= 1;
+			if (currHeight > 1)
+				currHeight >>= 1;
+		}
+		this->widthLog = (uchar)(std::log(mipmaps[0].cols) / CV_LOG2 + 0.0001f); // std::epsilon or something? or why 0.0001f here?
+		this->heightLog = (uchar)(std::log(mipmaps[0].rows) / CV_LOG2 + 0.0001f); // Changed std::logf to std::log because it doesnt compile in linux (gcc 4.8). CHECK THAT
+	};
+
+	std::vector<cv::Mat> mipmaps;	// make Texture a friend class of renderer, then move this to private?
+	unsigned char widthLog, heightLog; // log2 of width and height of the base mip-level
+
+private:
+	//std::string filename;
+	unsigned int mipmaps_num;
+};
 	} /* namespace render */
 } /* namespace eos */