nitro{gl}

Headers only C++11 OpenGL Vector Graphics library, that can run on all OpenGL/ES version.

Efficiently transforms a tree of shaders and samplers into a single shader at runtime.

Coming soon, Check out our website at micro-gl.github.io/docs/nitrogl

Example

#define NITROGL_OPENGL_MAJOR_VERSION 4
#define NITROGL_OPENGL_MINOR_VERSION 1
//#define NITROGL_OPEN_GL_ES

#include "src/example.h"
#include "src/Resources.h"
#include <nitrogl/samplers/texture_sampler.h>
#include <nitrogl/samplers/color_sampler.h>
#include <nitrogl/canvas.h>

using namespace nitrogl;

//using path_t = path<std::vector>;
using path_t = nitrogl::path<dynamic_array>;

path_t path_star() {
  path_t path{};
  path.lineTo({150, 150})
  .quadraticCurveTo({450, 0}, {450, 150})
  .lineTo({200,450})
  .lineTo({300,50})
  .lineTo({400,450})
  .closePath();
  return path;
}

int main() {

  // This can only run AFTER OpenGL has initilized !!!
  auto on_init = [](SDL_Window *, void *) {
    auto tex = gl_texture(100, 200);

    canvas canva(600, 600);

    auto tex_sampler_1 = texture_sampler(Resources::loadTexture("assets/images/test.png", true));
    auto tex_sampler_2 = texture_sampler(Resources::loadTexture("assets/images/test.png", false));
    auto tex_sampler_3 = texture_sampler(Resources::loadTexture("assets/images/uv_256.png", true), true);

    color_sampler sampler_color(1.0, 0.0, 0.0, 0.5f);

    // paths
    auto path = path_star();
    using il = std::initializer_list<int>;

    auto render = [&]() {
      canva.clear(1.0, 1.0, 1.0, 1.0);
      canva.drawPathStroke(
        sampler_color,
        path,
        12.0f,
        microtess::stroke_cap::round,
        microtess::stroke_line_join::round,
        5, il{0}, 0,
        mat3f::identity(),
        mat3f::identity()
      );
    };

    example_run<true>(canva, render);
  };

  example_init(on_init);
}

Installing nitro{gl}

nitrogl is a headers only library, which gives the following install possibilities:

1. Using cmake to invoke the install target, that will copy everything in your system via

$ mkdir cmake-build-release
$ cd cmake-build-release
$ cmake -DCMAKE_BUILD_TYPE=Release ..
$ cmake --install .

2. Copying the include/nitrogl to anywhere you want.

Consuming nitro{gl}

Following options are available:

1. copy the project to a sub folder of your project. inside your CMakeLists.txt add

add_subdirectory(/path/to/nitrogl)
target_link_libraries(your_app nitrogl)

2. If you installed nitro{gl} with option 1 (see above) at your system, you can instead

find_package(nitrogl CONFIG REQUIRED)
target_link_libraries(your_app nitrogl::nitrogl)

3. If you have not installed, you can add in your app's CMakeLists.txt

target_include_directories(app path/to/nitrogl/folder/include/)

4. If you manually copied the include/nitrogl to the default system include path,
   you can use cmake/Findnitrogl.cmake to automatically create the cmake targets

list(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/path/to/Findnitrogl/folder)
find_package(nitrogl REQUIRED)
target_link_libraries(your_app nitrogl::nitrogl)

5. Just copy the include/nitrogl into a sub folder of your project and include the header
   files you need with relative path in your source files.

Running Examples

First make sure you have

• SDL2 installed at your system.
• GLEW installed at your system.
• cmake installed at your system.

There are two ways:

1. Use your favourite IDE to load the root CMakeLists.txt file, and then it
   will pick up all of the targets, including the examples
2. Using the command line:

$ mkdir cmake-build-release
$ cd cmake-build-release
$ cmake -DCMAKE_BUILD_TYPE=Release ..
$ cmake --build . --target <example_name>
$ ../examples/bin/example_name

Author: Tomer Shalev, [email protected], all rights reserved (2022)