1 files changed, 185 insertions, 0 deletions
diff --git a/height-map-display/src/main.c b/height-map-display/src/main.c
new file mode 100644
index 0000000..5ad5c78
--- /dev/null
+++ b/height-map-display/src/main.c
@@ -0,0 +1,185 @@
+#include <GL/glew.h> // must come before glfw3
+#include <GLFW/glfw3.h>
+#include <stdio.h>
+#include <math.h>
+
+#define MAP_HEIGHT 10
+#define MAP_WIDTH 10
+
+int height_map[MAP_WIDTH][MAP_HEIGHT] = {
+    {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+    {0, 1, 1, 1, 1, 1, 1, 1, 1, 0},
+    {0, 1, 3, 3, 3, 3, 3, 3, 1, 0},
+    {0, 1, 3, 5, 5, 5, 5, 3, 1, 0},
+    {0, 1, 3, 5, 8, 8, 5, 3, 1, 0},
+    {0, 1, 3, 5, 8, 8, 5, 3, 1, 0},
+    {0, 1, 3, 5, 5, 5, 5, 3, 1, 0},
+    {0, 1, 3, 3, 3, 3, 3, 3, 1, 0},
+    {0, 1, 1, 1, 1, 1, 1, 1, 1, 0},
+    {0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+};
+
+// TODO: move into dedicated camera struct
+// Define the perspective projection matrix
+void perspective(float fov, float aspect, float near, float far, float *mat) {
+    float f = 1.0f / tan(fov * 0.5f);
+    mat[0] = f / aspect;
+    mat[1] = 0.0f;
+    mat[2] = 0.0f;
+    mat[3] = 0.0f;
+    mat[4] = 0.0f;
+    mat[5] = f;
+    mat[6] = 0.0f;
+    mat[7] = 0.0f;
+    mat[8] = 0.0f;
+    mat[9] = 0.0f;
+    mat[10] = (far + near) / (near - far);
+    mat[11] = -1.0f;
+    mat[12] = 0.0f;
+    mat[13] = 0.0f;
+    mat[14] = (2.0f * far * near) / (near - far);
+    mat[15] = 0.0f;
+}
+
+float camera_pos_x = 0.0f;
+float camera_pos_y = 0.0f;
+float camera_pos_z = 0.0f;
+float camera_yaw = 0.0f;    // rotation around y-axis
+float camera_pitch = 0.0f;  // rotation aroudn x-axis
+
+void renderHeightMap() {
+    float colors[3][3] = {
+        {0.0f, 1.0f, 0.0f}, // Green
+        {0.5f, 0.5f, 0.5f}, // Gray
+        {1.0f, 1.0f, 1.0f}  // White
+    };
+
+    float scale_factor = 1.0f;
+
+    glMatrixMode(GL_MODELVIEW);
+    glLoadIdentity();
+
+    glTranslatef(-camera_pos_x, -camera_pos_y, -camera_pos_z);
+    glRotatef(-camera_pitch, 1.0f, 0.0f, 0.0f);
+    glRotatef(-camera_yaw, 0.0f, 1.0f, 0.0f);
+
+    glMatrixMode(GL_PROJECTION);
+    glLoadIdentity();
+    glOrtho(-10.0, 10.0, -10.0, 10.0, -20.0, 20.0);
+
+    for (int x = 0; x < MAP_WIDTH - 1; x++) { // Adjusted loop bounds
+
+        glBegin(GL_TRIANGLE_STRIP);
+
+        for (int y = 0; y < MAP_HEIGHT; y++) {
+
+            float x0 = x;
+            float y0 = height_map[x][y] * scale_factor;
+            float z0 = y;
+
+            float x1 = x + 1; // Adjusted x1
+            float y1 = height_map[x+1][y] * scale_factor; // Adjusted indexing
+            float z1 = y;
+
+            float* color = colors[0];
+            if (y0 < 1.0f) { color = colors[1]; }
+            if (y0 < 0.5f) { color = colors[2]; }
+            glColor3fv(color);
+
+            glVertex3f(x0, y0, z0);
+            glVertex3f(x1, y1, z1);
+
+        }
+        glEnd();
+
+    }
+
+    // draw grid
+    
+    glColor3f(0.0f, 0.0f, 0.0f);
+    glLineWidth(1.0f);
+    glBegin(GL_LINES);
+
+    // Draw vertical grid lines
+    for (int x = 0; x <= MAP_WIDTH; x++) {
+        for (int y = 0; y < MAP_HEIGHT; y++) {
+            glVertex3f(x, height_map[x][y] * scale_factor, y);
+            glVertex3f(x, height_map[x][y + 1] * scale_factor, y + 1);
+        }
+    }
+
+    // Draw horizontal grid lines
+    for (int y = 0; y <= MAP_HEIGHT; y++) {
+        for (int x = 0; x < MAP_WIDTH; x++) {
+            glVertex3f(x, height_map[x][y] * scale_factor, y);
+            glVertex3f(x + 1, height_map[x + 1][y] * scale_factor, y);
+        }
+    }
+
+    glEnd();
+
+}
+
+void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods) {
+
+    const float camera_speed = 0.5f;
+
+    if (key == GLFW_KEY_W && action == GLFW_PRESS) { camera_pos_z -= camera_speed; }
+    else if (key == GLFW_KEY_S && action == GLFW_PRESS) { camera_pos_z += camera_speed; }
+    else if (key == GLFW_KEY_A && action == GLFW_PRESS) { camera_pos_x -= camera_speed; }
+    else if (key == GLFW_KEY_D && action == GLFW_PRESS) { camera_pos_x += camera_speed; }
+    else if (key == GLFW_KEY_Q && action == GLFW_PRESS) { camera_pitch -= camera_speed; }
+    else if (key == GLFW_KEY_E && action == GLFW_PRESS) { camera_pitch += camera_speed; }
+    else if (key == GLFW_KEY_Z && action == GLFW_PRESS) { camera_yaw -= camera_speed; }
+    else if (key == GLFW_KEY_C && action == GLFW_PRESS) { camera_yaw += camera_speed; }
+
+}
+
+int main(int argc, char *argv[]) {
+    GLFWwindow* window;
+
+    // initiate glfw library
+    if (!glfwInit()){
+        printf("Failed to initiate GLFW.\n");
+        return -1;
+    }
+
+    // create glfw window
+    GLFWmonitor* primary = glfwGetPrimaryMonitor();
+    const GLFWvidmode* mode = glfwGetVideoMode(primary);
+    window = glfwCreateWindow(mode->width, mode->height, "raycaster", primary, NULL);
+    if (!window){
+        printf("Failed to create GLFW window.\n");
+        glfwTerminate();
+        return -1;
+    }
+
+    // make window current
+    glfwMakeContextCurrent(window);
+    glewExperimental = GL_TRUE;
+    GLenum err = glewInit();
+    if (err != GLEW_OK) {
+        printf("GLEW init error");
+        return -1;
+    }
+
+    // enable depth testing
+    glEnable(GL_DEPTH_TEST);
+
+    glfwSetKeyCallback(window, key_callback);
+
+    while (!glfwWindowShouldClose(window)) {
+        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+        renderHeightMap();
+
+        glfwSwapBuffers(window); // Swap buffers to display the rendered image
+
+        // Poll for and process events, wait for events if none are pending
+        glfwWaitEventsTimeout(0.01); // Add a slight delay to reduce CPU usage
+    }
+
+    printf("Terminating GLFW...\n");
+    glfwTerminate();
+    return 0;
+}