Add helper methods to quickly render boxes (finalizing and #closes 696)

include/openspace/rendering/helper.h

@@ -0,0 +1,90 @@
+/*****************************************************************************************
+ *                                                                                       *
+ * OpenSpace                                                                             *
+ *                                                                                       *
+ * Copyright (c) 2014-2018                                                               *
+ *                                                                                       *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
+ * software and associated documentation files (the "Software"), to deal in the Software *
+ * without restriction, including without limitation the rights to use, copy, modify,    *
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
+ * permit persons to whom the Software is furnished to do so, subject to the following   *
+ * conditions:                                                                           *
+ *                                                                                       *
+ * The above copyright notice and this permission notice shall be included in all copies *
+ * or substantial portions of the Software.                                              *
+ *                                                                                       *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
+ * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
+ * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
+ * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
+ ****************************************************************************************/
+
+#ifndef __OPENSPACE_CORE___HELPER___H__
+#define __OPENSPACE_CORE___HELPER___H__
+
+#include <ghoul/opengl/uniformcache.h>
+
+namespace ghoul::opengl { class ProgramObject; }
+
+namespace openspace::rendering::helper {
+
+enum class Anchor {
+    Center,
+    NW,
+    NE,
+    SW,
+    SE
+};
+
+void initialize();
+void deinitialize();
+
+glm::mat4 ortho(const glm::vec2& position, const glm::vec2& size,
+    Anchor anchor = Anchor::NW);
+
+void renderBox(ghoul::opengl::ProgramObject& program, GLint orthoLocation,
+    GLint colorLocation, const glm::vec2& position, const glm::vec2& size,
+    const glm::vec4& color, Anchor anchor = Anchor::NW);
+
+void renderBox(const glm::vec2& position, const glm::vec2& size, const glm::vec4& color,
+    Anchor anchor = Anchor::NW);
+
+struct Shaders {
+    struct {
+        std::unique_ptr<ghoul::opengl::ProgramObject> program;
+        UniformCache(tex, hasTexture, shouldFlipTexture, ortho, color) cache;
+    } xyuvrgba;
+
+    struct {
+        std::unique_ptr<ghoul::opengl::ProgramObject> program;
+        UniformCache(tex, hasTexture, shouldFlipTexture, ortho, color) cache;
+    } screenfilling;
+};
+
+struct VertexObjects {
+    struct {
+        GLuint vao;
+        GLuint vbo;
+    } square;
+
+    struct {
+        GLuint vao;
+    } empty;
+};
+
+namespace detail {
+
+Shaders& gShadersConstructor();
+VertexObjects& gVertexObjectsConstructor();
+
+} // namespace detail
+
+static Shaders& shaders = detail::gShadersConstructor();
+static VertexObjects& vertexObjects = detail::gVertexObjectsConstructor();
+
+} // namespace openspace::rendering::helper
+
+#endif // __OPENSPACE_CORE___HELPER___H__