Use geometry shader for widgets.

data/shaderPrograms.json

@@ -23,7 +23,8 @@
         {
             "unique_name": "menuProgram",
             "vertexPath": "data/shaders/menu.vert",
-            "fragmentPath": "data/shaders/menu.frag"
+            "fragmentPath": "data/shaders/menu.frag",
+            "geometryPath": "data/shaders/menu.geom"
         },
         {
             "unique_name": "directionalShadowDepthProgram",

data/shaders/menu.frag

@@ -13,4 +13,5 @@ uniform Material u_material;
 void main()
 {
     f_color = texture(u_material.texture_diffuse0, v_texCoord);
+    // f_color = vec4(1.0, 0.0, 0.0, 0.5);
 }

data/shaders/menu.geom

@@ -0,0 +1,41 @@
+#version 330 core
+
+layout(points) in;
+layout(triangle_strip, max_vertices = 4) out;
+
+struct WidgetData
+{
+    vec2 position;
+    vec2 dimensions;
+};
+uniform WidgetData u_widgetData;
+
+out vec2 v_texCoord;
+
+void main()
+{
+    float glWidth = u_widgetData.dimensions.x * 2.0f;
+    float glHeight = u_widgetData.dimensions.y * 2.0f;
+
+    vec4 offset = vec4(0.0, 0.0, 0.0, 0.0);
+    gl_Position = gl_in[0].gl_Position + offset;
+    v_texCoord = vec2(0.0, 0.0);
+    EmitVertex();
+
+    offset = vec4(glWidth, 0.0, 0.0, 0.0);
+    gl_Position = gl_in[0].gl_Position + offset;
+    v_texCoord = vec2(1.0, 0.0);
+    EmitVertex();
+
+    offset = vec4(0.0, glHeight, 0.0, 0.0);
+    gl_Position = gl_in[0].gl_Position + offset;
+    v_texCoord = vec2(0.0, 1.0);
+    EmitVertex();
+
+    offset = vec4(glWidth, glHeight, 0.0, 0.0);
+    gl_Position = gl_in[0].gl_Position + offset;
+    v_texCoord = vec2(1.0, 1.0);
+    EmitVertex();
+
+    EndPrimitive();
+}

data/shaders/menu.vert

@@ -1,12 +1,16 @@
 #version 330 core
 
-layout(location = 0) in vec3 a_position;
-layout(location = 1) in vec2 a_texCoord;
-
-out vec2 v_texCoord;
+struct WidgetData
+{
+    vec2 position;
+    vec2 dimensions;
+};
+uniform WidgetData u_widgetData;
 
 void main()
 {
-    v_texCoord = a_texCoord;
-    gl_Position = vec4(a_position, 1.0);
+    float glPosX = u_widgetData.position.x * 2.0f - 1.0f;
+    float glPosY = u_widgetData.position.y * 2.0f - 1.0f;
+
+    gl_Position = vec4(glPosX, glPosY, 0, 1);
 }

data/shaders/postprocessing.vert

@@ -2,10 +2,11 @@
 
 out vec2 v_tex_coords;
 
-void main() {
+void main()
+{
     float x = -1.0 + float((gl_VertexID & 1) << 2);
     float y = -1.0 + float((gl_VertexID & 2) << 1);
-    v_tex_coords.x = (x+1.0)*0.5;
-    v_tex_coords.y = (y+1.0)*0.5;
+    v_tex_coords.x = (x + 1.0) * 0.5;
+    v_tex_coords.y = (y + 1.0) * 0.5;
     gl_Position = vec4(x, y, 0, 1);
 }

src/Controller.cpp

@@ -41,6 +41,7 @@ Controller::Controller() : m_gameWindow(std::unique_ptr<Window>(new Window))
 
     for (auto &prototype : shaderProgramPrototypes) {
         m_shaderPrograms.push_back(new ShaderProgram(prototype));
+        std::cout << "Loaded ShaderProgram \"" << prototype.name << "\"" << std::endl;
     }
 
     m_postProcessFrameBuffer = new FrameBuffer(m_gameWindow->getWindowWidth(), m_gameWindow->getWindowHeight(),

src/JsonParser.cpp

@@ -1,11 +1,4 @@
 #include "JsonParser.h"
-#include "Entity.h"
-#include "Light.h"
-#include "Model.h"
-#include "Screen.h"
-#include "ShaderProgram.h"
-#include "Texture.h"
-#include "Widget.h"
 
 #include <fstream>
 #include <iostream>
@@ -103,7 +96,6 @@ std::vector<ShaderProgram::Prototype> JsonParser::getShaderProgramPrototypes()
                                            shaderProgram_geometryPath};
 
         prototypes.push_back(prototype);
-        // std::cout << "Loaded ShaderProgram \"" << shaderProgram_name << "\"" << std::endl;
     }
 
     return prototypes;

src/ShaderProgram.cpp

@@ -128,6 +128,12 @@ void ShaderProgram::setUniform(const std::string &name, float value) const
     glUniform1f(location, value);
 }
 
+void ShaderProgram::setUniform(const std::string &name, glm::vec2 vector) const
+{
+    GLint location = retrieveUniformLocation(name);
+    glUniform2f(location, vector.x, vector.y);
+}
+
 void ShaderProgram::setUniform(const std::string &name, glm::vec3 vector) const
 {
     GLint location = retrieveUniformLocation(name);

src/ShaderProgram.h

@@ -28,6 +28,7 @@ public:
     void setUniform(const std::string &name, bool value) const;
     void setUniform(const std::string &name, int value) const;
     void setUniform(const std::string &name, float value) const;
+    void setUniform(const std::string &name, glm::vec2 vector) const;
     void setUniform(const std::string &name, glm::vec3 vector) const;
     void setUniform(const std::string &name, glm::mat3 matrix) const;
     void setUniform(const std::string &name, glm::mat4 matrix) const;

src/Widget.cpp

@@ -12,35 +12,12 @@ Widget::Widget(Prototype prototype, Texture *texture)
       m_callbackId(prototype.callBackId)
 {
     m_widgetTextures.push_back(texture);
-
-    double widgetVerticesData[12] = {
-        2 * (m_position.x + m_dimensions.x) - 1.0f,
-        2 * (m_position.y) - 1.0f,
-        0.0f, // Bottom right
-        2 * (m_position.x) - 1.0f,
-        2 * (m_position.y + m_dimensions.y) - 1.0f,
-        0.0f, // Top left
-        2 * (m_position.x) - 1.0f,
-        2 * (m_position.y) - 1.0f,
-        0.0f, // Bottom left
-        2 * (m_position.x + m_dimensions.x) - 1.0f,
-        2 * (m_position.y + m_dimensions.y) - 1.0f,
-        0.0f // Top right
-    };
-
-    unsigned int widgetIndicesData[6] = {0, 1, 2, 0, 3, 1};
-
-    float widgetTextureCoordinates[8] = {1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f};
-
-    m_widgetVertices = VertexArray::createVertices(widgetVerticesData, 12, widgetTextureCoordinates);
-    m_widgetIndices.assign(widgetIndicesData, widgetIndicesData + 6);
-    m_widgetMesh = new Mesh(m_widgetVertices, m_widgetIndices, m_widgetTextures);
-    m_widgetMesh->initializeOnGPU();
 }
 
 Widget::~Widget()
 {
-    delete m_widgetMesh;
+    for (auto &texture : m_widgetTextures)
+        delete texture;
 }
 
 std::string Widget::getUniqueName()
@@ -56,7 +33,28 @@ uint16_t Widget::getCallbackId()
 void Widget::draw(ShaderProgram *shaderProgram)
 {
     shaderProgram->bind();
-    m_widgetMesh->draw(shaderProgram);
+    shaderProgram->setUniform("u_widgetData.position", m_position);
+    shaderProgram->setUniform("u_widgetData.dimensions", m_dimensions);
+
+    GLint wireframe;
+    glGetIntegerv(GL_POLYGON_MODE, &wireframe);
+    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, m_widgetTextures[0]->getTextureId());
+
+    GLint location = glGetUniformLocation(shaderProgram->getShaderProgramId(), "u_texture");
+    glUniform1i(location, 0);
+
+    // A VAO is necessary although no data is stored in it
+    GLuint temp_vao;
+    glGenVertexArrays(1, &temp_vao);
+    glBindVertexArray(temp_vao);
+    glDrawArrays(GL_POINTS, 0, 3);
+    glBindVertexArray(0);
+
+    glPolygonMode(GL_FRONT_AND_BACK, wireframe);
+
     shaderProgram->unbind();
 }
 

src/Widget.h

@@ -43,9 +43,5 @@ private:
 
     uint16_t m_callbackId;
 
-    std::vector<Vertex> m_widgetVertices;
-    std::vector<uint32_t> m_widgetIndices;
     std::vector<Texture *> m_widgetTextures;
-
-    Mesh *m_widgetMesh;
 };