feat: establish stable OpenGL 3.3 core graphics conxtext

initializes the full graphics context pipeline required for modern OpenGL rendering

src/engine/renderer/camera/camera.c

@@ -3,34 +3,78 @@
 //
 
 #include "camera.h"
+#include "../..//core/logger/log.h"
 
+void camera_init(Camera *self, vec3 initial_position, int width, int height) {
+    // copy initial_pos vector
+    glm_vec3_copy(initial_position, self->Position);
+
+    // initialize orientation vector
+    glm_vec3_copy((vec3){0.0f, 0.0f, -1.0f}, self->Orientation);
+
+    // initialize up vector
+    glm_vec3_copy((vec3){0.0f, 1.0f, 0.0f}, self->Up);
+
+    // initialize controls and viewport
+    self->speed = 0.1f;
+    self->sensitivity = 100.0f;
+    self->FOV_deg = 45.0f;
+
+    self->width = width;
+    self->height = height;
+
+    // Init view matrix to identity (for first frame)
+    glm_mat4_identity(self->View);
+}
+
+/*
 Camera l_camera = {
     .Position = { 0.0f, 0.0f, 0.0f },
     .Orientation = { 0.0f, 0.0f, -1.0f },
     .Up = { 0.0f, 1.0f, 0.0f }
-};
+};*/
 
-void matrix(float FOVdeg, float nearPlane, float farPlane, Shader* shader_instance, const char* uniform) {
-    mat4 view, projection;
-    glm_mat4_identity(view);
-    glm_mat4_identity(projection);
-
-    // store the result of the vector addition
+void camera_update_view_matrix(Camera *self) {
+    // calc the center or target point (Pos + Orientation)
     vec3 target;
+    glm_vec3_add(self->Position, self->Orientation, target);
 
-    // cglm function to perform vector addition
-    glm_vec3_add(l_camera.Position, l_camera.Orientation, target);
-
-    mat4 target_2;
-
-    glm_mat4_mul(projection[0], view[0], target_2);
-
-    // now we can use the addition of the two vec3's in the glm_lookat() function
-    glm_lookat(l_camera.Position, target, l_camera.Up, view);
-
-    glm_perspective(glm_rad(FOVdeg), (float)(l_camera.width / l_camera.height), nearPlane, farPlane, projection);
-
-    glUniformMatrix4fv(glGetUniformLocation(shader_instance->ID, uniform), 1, GL_FALSE, target_2);
+    // create view matrix
+    glm_lookat(self->Position, target, self->Up, self->View);
 }
 
-void inputs(SDL_Window* window);
+void camera_update_projection(Camera *self, float nearPlane, float farPlane, mat4 dest) {
+    float aspect = (float)self->width / (float)self->height;
+    glm_perspective(glm_rad(self->FOV_deg), aspect, nearPlane, farPlane, dest);
+}
+
+// TODO: Update matrix function signature to accept camera entity?
+// change name to camera_upload_matrix for clarity?
+void camera_matrix_to_shader(Camera *self, GLuint shader_program_ID, const char *uniform_name) {
+    // update the view matrix first, camera position might have moved
+    camera_update_view_matrix(self);
+
+    // calculate projection matrix (P) with temporary matrix 'projection' for the result
+    mat4 projection;
+    camera_update_projection(self, 0.1f, 100.0f, projection);
+
+    // combine the matrices -- P * V -> PV
+    mat4 view_projection;
+    glm_mat4_mul(projection, self->View, view_projection);
+
+    // get uniform location
+    GLint uniform_location = glGetUniformLocation(shader_program_ID, uniform_name);
+
+    if (uniform_location == -1) {
+        log_error("Warning: Uniform '%s' not found in shader program %u.\n", uniform_name, shader_program_ID);
+        return;
+    }
+
+    // upload combined matrix to the shader
+    // view_projection[0] array pointer decays to first value
+    glUniformMatrix4fv(uniform_location, 1, GL_FALSE, view_projection[0]);
+}
+
+void camera_inputs(Camera *self, SDL_Event *event) {
+    // TODO: implementation for handling keyboard/mouse inputs for camera
+}