Add stb_image so we can begin texture work

src/CMakeLists.txt

@@ -1,6 +1,7 @@
 add_executable(Exponent
     main.cc
     GLProgramLoader.cc
+    stb_image.cc
 )
 
 target_link_libraries(Exponent PUBLIC glfw glm::glm)

src/main.cc

@@ -18,6 +18,8 @@
 #include <glm/ext.hpp>
 #include <glm/mat2x2.hpp>
 
+#include <stb/stb_image.h>
+
 static void dbg_log(const char* str) {
     std::cout << str << std::endl;
 }
@@ -58,15 +60,15 @@ static void init_shaders() {
     rotate_unif = glGetUniformLocation(g_program_id, "rotation");
 }
 
-class Triangle {
+class Quad {
 public:
-    GLfloat data[6];
+    GLfloat data[12];
-    float m_pos_x;
+    float m_pos_x = 0;
-    float m_pos_y;
+    float m_pos_y = 0;
-    float rotation = 0.2f;
+    float rotation = 0.0f;
 
-    Triangle(std::array<glm::vec2, 3> verts) {
+    Quad(std::array<glm::vec2, 6> verts) {
-        for (std::size_t i = 0; i < 3; i++) {
+        for (std::size_t i = 0; i < 6; i++) {
             data[i*2] = verts[i][0];
             data[i*2+1] = verts[i][1];
         }
@@ -81,10 +83,15 @@ static GLuint vertex_buf[2];
 static GLuint array_buf[2];
 static const GLuint vertex_data_position = 0;
 
-static Triangle o1(std::array<glm::vec2, 3>({
+static Quad o1(std::array<glm::vec2, 6>({
+        // Tri 2
         {0.0f, 0.0f},
         {0.5f, 0.0f},
-        {0.5f, 0.5f}
+        {0.5f, 0.5f},
+        // Tri 1
+        {0.0f, 0.0f},
+        {0.5f, 0.5f},
+        {0.0f, 0.5f},
     }));
 
 // Do the work of initialising opengl so we can draw stuff
@@ -98,7 +105,7 @@ static void init_opengl() {
 
     glGenBuffers(2, vertex_buf);
     glBindBuffer(GL_ARRAY_BUFFER, vertex_buf[0]);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(Triangle::data), o1.data, GL_STATIC_DRAW);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(Quad::data), o1.data, GL_STATIC_DRAW);
     glVertexAttribPointer(vertex_data_position, 2, GL_FLOAT, GL_FALSE, 0, NULL);
     glEnableVertexAttribArray(vertex_data_position);
 
@@ -135,13 +142,18 @@ int main() {
     while(!glfwWindowShouldClose(w)) {
         float time = glfwGetTime();
 
+        o1.rotation = 2*sin(time);
+
+        o1.m_pos_x = 0.25*sin(time);
+        o1.m_pos_y = 0.5*cos(time);
+
         glClear(GL_COLOR_BUFFER_BIT);
 
         glUniform2fv(translate_unif, 1, o1.get_world_projection().data());
         glUniform1f(rotate_unif, o1.rotation);
 
         glBindVertexArray(array_buf[0]);
-        glDrawArrays(GL_TRIANGLES, 0, 3);
+        glDrawArrays(GL_TRIANGLES, 0, 6);
 
         glfwSwapBuffers(w);
         glfwPollEvents();

src/stb_image.cc

@@ -0,0 +1,2 @@
+#define STB_IMAGE_IMPLEMENTATION
+#include <stb/stb_image.h>