works

assignment-2a/Makefile

@@ -7,7 +7,7 @@ SOURCES := $(shell find -name "*.cpp")
 
 all: $(HANDIN)
 
-$(HANDIN): src/HW2a.cpp README.md
+$(HANDIN): src/HW2a.cpp examples README.md
 	$(ZIP) -r $@ $^
 
 clean:

assignment-2a/README.md

@@ -1,3 +1,13 @@
 # Assignment 2A
 
-Should compile on CSE labs machines.
+Compiles but does not run on CSE labs machines due to OpenGL 3.2 missing.
+
+Try with `examples/test.obj`, run the program with
+
+    cmake -B build
+    make -C build
+    ./build/HW2a examples/test.obj
+
+This test has a few triangles in it. Other obj files _should_ work in theory
+
+![](examples/test.png)

assignment-2a/examples/test.obj

@@ -0,0 +1,11 @@
+v 2 3 0
+v 1.5 4 0
+v 3 2 0
+
+v 1.5 4 0
+v 3 2 0
+v 5 3.4 0
+
+v 3 2 0
+v 5 3.4 0
+v 6 5.9 0

assignment-2a/src/HW2a.cpp

@@ -25,7 +25,7 @@
 
 // repetitive of the debug flag in the shader loading code, included here
 // for clarity only
-#define DEBUG_ON 1
+#define DEBUG_ON 0
 
 // This file contains the code that reads the shaders from their files and
 // compiles them
@@ -207,26 +207,79 @@ void init(void) {
       exit(1);
     }
 
-    string contents, line;
-    f >> contents;
-    f.close();
+    float max_x = -INFINITY;
+    float min_x = INFINITY;
+    float max_y = -INFINITY;
+    float min_y = INFINITY;
 
-    istringstream iss(contents);
-    for (std::string line; std::getline(iss, line);) {
-      printf("line: '%s'\n", line.c_str());
-      if (line.find_first_not_of("\t\n ") == string::npos) {
-        continue;
-      }
+    string line;
+    while (std::getline(f, line)) {
+      std::istringstream iss(line);
+      string tmp;
 
-      istringstream iss2(line);
-      string a;
-      std::getline(iss2, a, ',');
+      std::getline(iss, tmp, ' ');
+      if (tmp == "v") {
+        float x, y, z;
 
-      if (a == "v") {
-        printf("hello %s\n", line.c_str());
+        std::getline(iss, tmp, ' ');
+        x = std::stof(tmp);
+        std::getline(iss, tmp, ' ');
+        y = std::stof(tmp);
+        std::getline(iss, tmp, ' ');
+        z = std::stof(tmp);
+
+        // printf("(%f, %f, %f)\n", x, y, z);
+
+        max_x = max(x, max_x);
+        max_y = max(y, max_y);
+        min_x = min(x, min_x);
+        min_y = min(y, min_y);
+
+        vertices.push_back({.x = x, .y = y});
       }
     }
 
+    // Scale it a little bit so it fits in frame
+    float obj_scale_x = 1.0 / (max_x - min_x);
+    float obj_scale_y = 1.0 / (max_x - min_x);
+
+    for (int i = 0; i < vertices.size(); ++i) {
+      vertices[i].x = vertices[i].x * obj_scale_x - 1.0;
+      vertices[i].y = vertices[i].y * obj_scale_y - 1.0;
+    }
+
+    // Assign some random colors to it
+    const float delta_r = 0.4, delta_g = 0.7, delta_b = -0.5;
+    float r = 0.5, g = 0.7, b = 0.8;
+    for (auto _ : vertices) {
+      colors.push_back({.r = r, .g = g, .b = b});
+
+      r += delta_r;
+      g += delta_g;
+      b += delta_b;
+
+      while (r > 1.0)
+        r -= 1.0;
+      while (r < 0.0)
+        r += 1.0;
+      while (g > 1.0)
+        g -= 1.0;
+      while (g < 0.0)
+        g += 1.0;
+      while (b > 1.0)
+        b -= 1.0;
+      while (b < 0.0)
+        b += 1.0;
+    }
+
+    for (int i = 0; i < vertices.size(); ++i) {
+      auto &vertex = vertices[i];
+      auto &color = colors[i];
+      printf(
+          "vertex (%f, %f) is color (%f, %f, %f)\n", vertex.x, vertex.y,
+          color.r, color.g, color.b
+      );
+    }
   } else {
     // clang-format off
     // set up some hard-coded colors and geometry
@@ -257,19 +310,20 @@ void init(void) {
   glGenVertexArrays(1, vao);
   glBindVertexArray(vao[0]);
 
+  const uint32_t vertices_size = vertices.size() * sizeof(FloatType2D);
+  const uint32_t colors_size = colors.size() * sizeof(ColorType3D);
+  // printf("%d , %d\n", vertices_size, colors_size);
+
   // Create and initialize a buffer object large enough to hold both vertex
   // position and color data
   glGenBuffers(1, &buffer);
   glBindBuffer(GL_ARRAY_BUFFER, buffer);
-  cout << vertices.size() << " " << colors.size() << endl;
   glBufferData(
-      GL_ARRAY_BUFFER, vertices.size() + colors.size(), vertices.data(),
+      GL_ARRAY_BUFFER, vertices_size + colors_size, vertices.data(),
       GL_STATIC_DRAW
   );
-  glBufferSubData(GL_ARRAY_BUFFER, 0, vertices.size(), vertices.data());
-  glBufferSubData(
-      GL_ARRAY_BUFFER, vertices.size(), colors.size(), colors.data()
-  );
+  glBufferSubData(GL_ARRAY_BUFFER, 0, vertices_size, vertices.data());
+  glBufferSubData(GL_ARRAY_BUFFER, vertices_size, colors_size, colors.data());
 
   // Define the names of the shader files
   std::stringstream vshader, fshader;