collision

src/ray.c

@@ -11,18 +11,17 @@ float v2_len(v2 a) {
     return sqrt(a.x * a.x + a.y * a.y);
 }
 
+float v2_dist(v2 a, v2 b) {
+    return sqrt(v2_square_dist(a, b));
+}
+
 float v2_square_dist(v2 a, v2 b) {
     return pow(a.x - b.x, 2) + pow(a.y - b.y, 2);
 }
 
-#define PI		3.14159265358979323846
-#define PIH		1.57079632679489661923
-#define PI2		6.28318530718
-
 uint32_t cast_ray(v2 pos, float theta, v2* hit_pos) {
 
     const v2i move = {
-        #define sign(a) ((a) < 0 ? -1 : 1)
         sign(cos(theta)),
         sign(sin(theta)),
     };

src/ray.h

@@ -3,6 +3,14 @@
 #include <stdbool.h>
 #include <stdint.h>
 
+#define PI		3.14159265358979323846
+#define PIH		1.57079632679489661923
+#define PI2		6.28318530718
+
+#define sign(a) ((a) < 0 ? -1 : 1)
+#define min(a, b) ((a) < (b) ? (a) : (b))
+#define max(a, b) ((a) > (b) ? (a) : (b))
+
 typedef struct {
     float x, y;
 } v2;
@@ -11,10 +19,9 @@ typedef struct {
     int x, y;
 } v2i;
 
-
 float v2_cross(v2 a, v2 b);
 float v2_len(v2 a);
+float v2_dist(v2 a, v2 b);
 float v2_square_dist(v2 a, v2 b);
-v2 v2_add(v2 a, v2 b);
 
 uint32_t cast_ray(v2 pos, float theta, v2* hit_pos); 

src/renderer.c

@@ -3,14 +3,12 @@
 #include "ray.h"
 
 #include <math.h>
+#include <string.h>
 
-#define PI		3.14159265358979323846
-#define PIH		1.57079632679489661923
-#define PI2		6.28318530718
 
 void init_camera(Camera* camera) {
-    camera->x = 3;
-    camera->y = 3;
+    camera->pos.x = 3;
+    camera->pos.y = 3;
     camera->angle = PI / 4;
 }
 
@@ -19,6 +17,8 @@ static double fov = PI / 4;
 #define MOVE_SPEED      1
 #define ROTATE_SPEED    PI / 2
 #define FOV_CHANGE_SPEED 1
+#define PLAYER_SIZE .1
+
 void update_camera(Camera* camera, Screen* screen) {
     double rotate = 0;
 
@@ -39,7 +39,7 @@ void update_camera(Camera* camera, Screen* screen) {
     v2 left = { forward.y, -forward.x }; 
     v2 move = { 0, 0 };
 
-        if (key_pressed(screen, SDL_SCANCODE_W)) {
+    if (key_pressed(screen, SDL_SCANCODE_W)) {
         move.x += forward.x;
         move.y += forward.y;
     }
@@ -67,16 +67,17 @@ void update_camera(Camera* camera, Screen* screen) {
         fov -= FOV_CHANGE_SPEED * screen->delta;
     }
 
-    camera->x += move.x * MOVE_SPEED * screen->delta;
-    camera->y += move.y * MOVE_SPEED * screen->delta;
-}
+    v2 hit_pos;
+    bool movex, movey;
 
-v2 get_cam_right(const Camera* camera) {
-    v2 cam_right = {
-        -sin(camera->angle),
-        cos(camera->angle)
-    };
-    return cam_right;
+    cast_ray(camera->pos, sign(move.x) == 1 ? 0 : PI, &hit_pos);
+    movex = v2_dist(hit_pos, camera->pos) > PLAYER_SIZE;
+
+    cast_ray(camera->pos, sign(move.y) == 1 ? PIH : -PIH, &hit_pos);
+    movey = v2_dist(hit_pos, camera->pos) > PLAYER_SIZE;
+
+    if (movex) camera->pos.x += move.x * MOVE_SPEED * screen->delta;
+    if (movey) camera->pos.y += move.y * MOVE_SPEED * screen->delta;
 }
 
 static void verline(Screen* screen, int x, int y0, int y1, uint32_t color) {
@@ -85,29 +86,23 @@ static void verline(Screen* screen, int x, int y0, int y1, uint32_t color) {
     }
 }
 
-#define min(a, b) ((a) < (b) ? (a) : (b))
-#define max(a, b) ((a) > (b) ? (a) : (b))
-
 void render(Screen* screen, const Camera* camera) {
 
-    const v2 pos = {
-        camera->x,
-        camera->y
+    const v2 cam_right = {
+        -sin(camera->angle),
+        cos(camera->angle)
     };
 
-    const v2 cam_right = get_cam_right(camera);
-
-    for (int sx = 0; sx < screen->width; sx++) {
-
-        const float xcam = (2 * (sx / (float) (screen->width))) - 1;
+    for (int x = 0; x < screen->width; x++) {
+        const float xcam = (2 * (x / (float) (screen->width))) - 1;
         const float change = fov * atan(xcam);
         const float theta = camera->angle + change;
 
         v2 hit_pos;
-        uint32_t hit = cast_ray(pos, theta, &hit_pos);
+        uint32_t hit = cast_ray(camera->pos, theta, &hit_pos);
 
-        hit_pos.x -= pos.x;
-        hit_pos.y -= pos.y;
+        hit_pos.x -= camera->pos.x;
+        hit_pos.y -= camera->pos.y;
 
         float len = v2_cross(hit_pos, cam_right) / v2_len(cam_right);
 
@@ -120,13 +115,14 @@ void render(Screen* screen, const Camera* camera) {
             case 5: color = 0x00FFFFFF; break;
             default: color = 0x000000FF; break;
         }
+
         const int
             h = (int) (screen->height / len),
             y0 = max((screen->height / 2) - (h / 2), 0),
             y1 = min((screen->height / 2) + (h / 2), screen->height - 1);
 
-        verline(screen, sx, 0, y0, 0x202020FF);
-        verline(screen, sx, y0, y1, color);
-        verline(screen, sx, y1, screen->height - 1, 0x505050FF);
+        verline(screen, x, 0, y0, 0x202020FF);
+        verline(screen, x, y0, y1, color);
+        verline(screen, x, y1, screen->height - 1, 0x505050FF);
     }
 }

src/renderer.h

@@ -4,12 +4,11 @@
 #include "ray.h"
 
 typedef struct {
-    float x, y;
+    v2 pos;
     float angle;
 } Camera;
 
 void init_camera(Camera* camera);
 void update_camera(Camera* camera, Screen* screeen);
-v2 get_cam_right(const Camera* camera);
 
 void render(Screen* screen, const Camera* camera);