ortho projection

src/camera.h

@@ -0,0 +1,11 @@
+#ifndef CAMERA_H
+#define CAMERA_H
+
+
+typedef struct {
+  vec3_t position;
+  vec3_t rotation;
+  float fov_angle;
+} camera_t;
+
+#endif

src/display.c

@@ -1,3 +1,4 @@
+#include <stdio.h>
 #include "display.h"
 
 SDL_Window *window = NULL;
@@ -64,26 +65,34 @@ void render_color_buffer(void) {
     SDL_RenderCopy(renderer, color_buffer_texture, NULL, NULL);
 }
 
-void draw_grid(int size) {
+void draw_grid() {
     if (color_buffer == NULL) {
         return;
     }
     for (int y = 0; y < window_height; y++) {
         for (int x = 0; x < window_width; x++) {
-            if (y % size == 0 || x % size == 0) {
-                draw_pixel(x, y, 0xFF333333);
+            if (y % 10 == 0 || x % 10 == 0) {
+                color_buffer[(window_width * y) + x] = 0xFF444444;
             }
         }
     }
 }
 
+void draw_pixel(int x, int y, uint32_t color) {
+    if ( x >= 0 && x < window_width && y >= 0 && y < window_height) {
+        color_buffer[(window_width * y) + x] = color;
+    }
+}
+
 void draw_rect(int x, int y, int width, int height, uint32_t color) {
     if (color_buffer == NULL) {
         return;
     }
-    for (int i = y; i < height + y; i++) {
-        for (int j = x; j < width; j++) {
-            draw_pixel(x + j, y + i, color);
+    for (int i = 0; i < width; i++) {
+        for (int j = 0; j < height; j++) {
+            int current_x = x + i;
+            int current_y = y + j;
+            draw_pixel(current_x, current_y, color);
         }
     }
 }
@@ -96,8 +105,3 @@ void destroy_window(void) {
     SDL_Quit();
 }
 
-void draw_pixel(int x, int y, uint32_t color) {
-    if (x < window_width && y < window_height) {
-        color_buffer[(window_width * y) + x] = color;
-    }
-}

src/display.h

@@ -15,7 +15,7 @@ extern int window_height;
 
 bool initialize_window(void);
 
-void draw_grid(int size);
+void draw_grid();
 
 void draw_pixel(int x, int y, uint32_t color);
 

src/main.c

@@ -9,6 +9,8 @@
 ////////////////////////////////////////////////////////////
 #define N_POINTS  (9 * 9 * 9)
 vec3_t cube_points[N_POINTS];
+vec2_t projected_points[N_POINTS];
+float fov_factor = 128;
 
 
 bool is_running = false;
@@ -52,19 +54,44 @@ void process_input(void) {
   }
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// Function that receives a 3d Vector and returns a 2d projected point
+////////////////////////////////////////////////////////////////////////////////
+vec2_t project(vec3_t point) {
+  vec2_t projected_point = {
+    .x = (fov_factor * point.x),
+    .y = (fov_factor * point.y),
+  };
+  return projected_point;
+}
+
 
 void update(void) {
+    for (int i = 0; i < N_POINTS; i++){
+        vec3_t point = cube_points[i];
+        vec2_t projected_point = project(point);
+        
+        projected_points[i] = projected_point;
+    }
 }
 
 
 void render(void) {
-  SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
-  SDL_RenderClear(renderer);
+  draw_grid();
+
+  for (int i = 0; i < N_POINTS; i++){
+    vec2_t projected_point = projected_points[i];
+    draw_rect(
+      projected_point.x + (window_width/2),
+      projected_point.y + (window_height/2),
+      4,
+      4,
+      0xFFFFFF00
+    );
+  }
 
-  clear_color_buffer(0xFF000000);
-  draw_grid(10);
-  draw_rect(50, 50, 640, 480, 0xFFDD00DD);
   render_color_buffer();
+  clear_color_buffer(0xFF000000);
 
   SDL_RenderPresent(renderer);
 }

src/vector.c

@@ -0,0 +1,3 @@
+#include "vector.h"
+
+// Implement all vector functons

src/vector.h

@@ -0,0 +1,18 @@
+#ifndef VECTOR_H
+#define VECTOR_H
+
+typedef struct {
+  float x;
+  float y;
+} vec2_t;
+
+
+typedef struct {
+  float x;
+  float y;
+  float z;
+} vec3_t;
+
+
+
+#endif