Mostly working textures, an ability to look up/down (pitch) and ready to read in images for the textures.

fenscaster.cpp

@@ -1,5 +1,6 @@
 #include <fmt/core.h>
 #include <numbers>
+#include <algorithm>
 #include <cmath>
 #include "matrix.hpp"
 #include <cstdlib>
@@ -10,14 +11,14 @@ using matrix::Matrix;
 using namespace fmt;
 
 Matrix MAP{
-  {1,1,1,1,1,1,1,1,1},
-  {1,0,1,0,0,0,0,0,1},
-  {1,0,1,0,0,1,1,0,1},
-  {1,0,0,0,0,0,0,0,1},
-  {1,1,0,0,0,0,0,1,1},
-  {1,0,0,1,1,1,0,0,1},
-  {1,0,0,0,0,0,1,1,1},
-  {1,1,1,1,1,1,1,1,1}
+  {2,2,2,2,2,2,2,2,2},
+  {2,0,8,0,0,0,0,0,2},
+  {2,0,7,0,0,5,6,0,2},
+  {2,0,0,0,0,0,0,0,2},
+  {2,2,0,0,0,0,0,2,2},
+  {2,0,0,1,3,4,0,0,2},
+  {2,0,0,0,0,0,2,2,2},
+  {2,2,2,2,2,2,2,2,2}
 };
 
 const int SCREEN_HEIGHT=480;
@@ -33,6 +34,7 @@ const int CASTED_RAYS=120;
 const float STEP_ANGLE = FOV / CASTED_RAYS;
 const int MAX_DEPTH = MAP_SIZE * TILE_SIZE;
 const float SCALE = (SCREEN_WIDTH / 2) / CASTED_RAYS;
+int PITCH=25;
 
 float player_x = SCREEN_WIDTH / 4;
 float player_y = SCREEN_WIDTH / 4;
@@ -56,6 +58,7 @@ std::vector<uint32_t> texture[8];
 #define texWidth 64
 #define texHeight 64
 
+
 void load_textures() {
   for(int i = 0; i < 8; i++) {
     texture[i].resize(texWidth * texHeight);
@@ -111,7 +114,7 @@ void draw_map(Fenster &window, Matrix &map) {
 
   for(size_t y = 0; y < matrix::height(map); y++) {
     for(size_t x = 0; x < matrix::width(map); x++) {
-      draw_map_rect(window, x, y, map[y][x] == 1 ? light_grey : dark_grey);
+      draw_map_rect(window, x, y, map[y][x] == 0 ? dark_grey : light_grey);
     }
   }
 }
@@ -231,30 +234,57 @@ void ray_casting(Fenster &window, Matrix& map) {
 
     int lineHeight = int(h / perpWallDist);
 
-    int drawStart = -lineHeight / 2 + h / 2;
+    int drawStart = -lineHeight / 2 + h / 2 + PITCH;
     if(drawStart < 0) drawStart = 0;
 
-    int drawEnd = lineHeight / 2 + h / 2;
+    int drawEnd = lineHeight / 2 + h / 2 + PITCH;
     if(drawEnd >= h) drawEnd = h - 1;
 
-    uint32_t color = gray_color(std::min(lineHeight, 255));
+    int texNum = MAP[mapY][mapX] - 1;
+
+    // calculate value of wallX
+    double wallX;  // where exactly the wall was hit
+    if(side == 0) {
+      wallX = posY + perpWallDist * rayDirY;
+    } else {
+      wallX = posX + perpWallDist * rayDirX;
+    }
+    wallX -= floor((wallX));
+
+    // x coorindate on the texture
+    int texX = int(wallX * double(texWidth));
+    if(side == 0 && rayDirX > 0) texX = texWidth - texX - 1;
+    if(side == 1 && rayDirY < 0) texX = texWidth - texX - 1;
+
+    // LODE: an integer-only bresenham or DDA like algorithm could make the texture coordinate stepping faster
 
-    draw_line(window,
-        {size_t(x + THREED_VIEW_WIDTH), size_t(drawStart)},
-        {size_t(x + THREED_VIEW_WIDTH), size_t(drawEnd)}, color);
+    // How much to increase the texture coordinate per screen pixel
+    double step = 1.0 * texHeight / lineHeight;
+    // Starting texture coordinate
+    double texPos = (drawStart - PITCH - h / 2 + lineHeight / 2) * step;
+
+    for(int y = drawStart; y < drawEnd; y++) {
+      // BUG? Why bitwise and here?
+      int texY = (int)texPos & (texHeight - 1);
+      texPos += step;
+      uint32_t color = texture[texNum][texHeight * texY + texX];
+
+      if(side == 1) color = (color >> 1) & 8355711;
+      window.px(x + THREED_VIEW_WIDTH, y) = color;
+    }
   }
 }
 
-
 void draw_ceiling_floor(Fenster &window) {
-  draw_rect(window,
-      {size_t(window.width() / 2), 0},
-      {size_t(window.height()), size_t(window.height() / 2)},
-      gray_color(100));
   draw_rect(window,
       {size_t(window.width() / 2), size_t(window.height() / 2)},
       {size_t(window.width() / 2), size_t(window.height() / 2)},
       gray_color(200));
+
+  draw_rect(window,
+      {size_t(window.width() / 2), 0},
+      {size_t(window.height()), size_t(window.height() / 2 + PITCH)},
+      gray_color(100));
 }
 
 void draw_everything(Fenster &window) {
@@ -292,7 +322,7 @@ int main() {
         if(empty_space(int(posX), int(posY - dirY * moveSpeed))) posY -= dirY * moveSpeed;
     }
 
-    if(window.key('E')) {
+    if(window.key('D')) {
       double oldDirX = dirX;
       dirX = dirX * cos(-rotSpeed) - dirY * sin(-rotSpeed);
       dirY = oldDirX * sin(-rotSpeed) + dirY * cos(-rotSpeed);
@@ -300,7 +330,7 @@ int main() {
       double oldPlaneX = planeX;
       planeX = planeX * cos(-rotSpeed) - planeY * sin(-rotSpeed);
       planeY = oldPlaneX * sin(-rotSpeed) + planeY * cos(-rotSpeed);
-    } else if(window.key('Q')) {
+    } else if(window.key('A')) {
       double oldDirX = dirX;
       dirX = dirX * cos(rotSpeed) - dirY * sin(rotSpeed);
       dirY = oldDirX * sin(rotSpeed) + dirY * cos(rotSpeed);
@@ -310,10 +340,10 @@ int main() {
       planeY = oldPlaneX * sin(rotSpeed) + planeY * cos(rotSpeed);
     }
 
-    if(window.key('D')) {
-      println("NOT IMPLEMENTED USE E");
-    } else if(window.key('A')) {
-      println("NOT IMPLEMENTED USE Q");
+    if(window.key('E')) {
+      PITCH = std::clamp(PITCH + 10, -60, 240);
+    } else if(window.key('Q')) {
+      PITCH = std::clamp(PITCH - 10, -60, 240);
     }
   }