Misc (#19)

* get image returns optional<Mat> instead of unique_ptr<Mat> * introduce complexity * rename image load function * add example for a basic reader for binary image files * fix windows build? * add a status bar underneath the menu bar * use status bar in custom_0 example app * clang formats * packing w/ pragma push * add "Save As" functions to image views * resize over reserve * rm local override uri * add simple thread pool * rename to simple_thread_pool * get rid of useless renderlib * document version inc * extract hardcoded values to in-header * clang format patch * clone registered image in custom_0 * document binary-file header * minor fixes * clang format * rm unused render cmake
2026-01-23 23:00:35 +00:00
parent e3e161ce52
commit b37814204f
52 changed files with 712 additions and 207 deletions
@@ -0,0 +1,123 @@
+#include "CvMatRender.hpp"
+
+#include <opencv2/core/mat.hpp>
+#include <opencv2/imgproc.hpp>
+
+#include "imaging/IPixelariumImage.hpp"
+
+using namespace pixelarium::imaging;
+
+/// @brief Constructor for the CvMatRender class.
+/// @param img A shared pointer to the PixelariumImage to be rendered.
+pixelarium::application::CvMatRender::CvMatRender(const cv::Mat& img) : base_(img), texture_(0)
+{
+    // storing a copy of the to-be-rendered image
+    // because it will be resized and filtered eventually which we absolutely
+    // must not do on the original image
+    this->ResetRenderImage();
+    cv::cvtColor(this->img_, this->img_, cv::COLOR_BGR2RGBA);
+}
+
+/// @brief Destructor for the CvMatRender class.
+/// Deallocates the OpenGL texture if it exists.
+pixelarium::application::CvMatRender::~CvMatRender()
+{
+    if (texture_)
+    {
+        glDeleteTextures(1, &texture_);
+        texture_ = 0;
+    }
+}
+
+/// @brief Uploads the current image data to an OpenGL texture.
+/// @return The ID of the uploaded OpenGL texture.
+/// @throws std::runtime_error if the image data is empty or if there is an OpenGL error.
+GLuint pixelarium::application::CvMatRender::uploadTexture()
+{
+    if (img_.empty())
+    {
+        throw std::runtime_error("Image data is empty.");
+    }
+
+    if (!this->texture_)
+    {
+        glGenTextures(1, &this->texture_);
+        if (this->texture_ == 0)
+        {
+            throw std::runtime_error("Failed to generate OpenGL texture.");
+        }
+    }
+
+    glBindTexture(GL_TEXTURE_2D, this->texture_);
+
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+    const int width = img_.cols;
+    const int height = img_.rows;
+    // see
+    // https://stackoverflow.com/questions/10167534/how-to-find-out-what-type-of-a-mat-object-is-with-mattype-in-opencv
+    // for pixel a pixel type table
+    switch (img_.type())
+    {
+        case CV_8U:
+            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_BYTE, img_.data);
+            break;
+        case CV_16U:
+        case CV_16UC3:
+        case CV_16UC4:
+            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_SHORT, img_.data);
+            break;
+        case CV_32F:
+        case CV_32FC4:
+            glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, width, height, 0, GL_DEPTH_COMPONENT, GL_FLOAT,
+                         img_.data);
+            break;
+        default:
+            glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, img_.cols, img_.rows, 0, GL_RGBA, GL_UNSIGNED_BYTE, img_.data);
+            break;
+    }
+
+    GLenum error = glGetError();
+    if (error != GL_NO_ERROR)
+    {
+        throw std::runtime_error("OpenGL error during texture upload: " + std::to_string(error));
+    }
+
+    return this->texture_;
+}
+
+/// @brief Renders the image by uploading it as a texture.
+/// @return The ID of the OpenGL texture.
+GLuint pixelarium::application::CvMatRender::Render() { return this->uploadTexture(); }
+
+/// @brief Renders the image with a specified scaling factor.
+/// @param factor The scaling factor for resizing the image.
+/// @return The ID of the OpenGL texture.
+GLuint pixelarium::application::CvMatRender::Render(float factor)
+{
+    cv::resize(this->base_, this->img_, cv::Size(0, 0), factor, factor, cv::INTER_LINEAR_EXACT);
+
+    return this->uploadTexture();
+}
+
+/// @brief Renders the image to fit within the specified width and height.
+/// @param width The maximum width of the rendered image.
+/// @param height The maximum height of the rendered image.
+/// @return The ID of the OpenGL texture.
+GLuint pixelarium::application::CvMatRender::Render(size_t width, size_t height)
+{
+    const auto sz{this->base_.size()};
+
+    const auto get_factor = [](auto opt1, auto opt2) -> float { return opt1 < opt2 ? opt1 : opt2; };
+
+    auto factor = get_factor(width / static_cast<float>(sz.width), height / static_cast<float>(sz.height));
+
+    return this->Render(factor);
+}
+
+void pixelarium::application::CvMatRender::ResetRenderImage()
+{
+    // we copy here
+    this->img_ = this->base_.clone();
+}