From 195817f2d99bf8f33a1ad796a7f00788531af452 Mon Sep 17 00:00:00 2001
From: Hans Kokx <hans.d.kokx@gmail.com>
Date: Wed, 2 Sep 2026 17:20:08 +0200
Subject: [PATCH] Fix texture mapping

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>
---
 raycaster.c | 112 +++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 88 insertions(+), 24 deletions(-)

diff --git a/raycaster.c b/raycaster.c
index 4d1eebb..0d1782b 100644
--- a/raycaster.c
+++ b/raycaster.c
@@ -270,20 +270,6 @@ void drawRays2D()
 
   int shiftSize = (int)(log2f((float)mapSize));
 
-  glColor3f(0, 1, 1);
-  glBegin(GL_QUADS);
-  glVertex2i(526, 0);
-  glVertex2i(1006, 0);
-  glVertex2i(1006, 160);
-  glEnd();
-
-  glColor3f(0, 0, 1);
-  glBegin(GL_QUADS);
-  glVertex2i(526, 160);
-  glVertex2i(1006, 160);
-  glVertex2i(1006, 320);
-  glEnd();
-
   // Ray x, y, angle
   float rayX, rayY, rayAngle;
 
@@ -516,6 +502,22 @@ void drawRays2D()
 // * Draws the top-down map with white alls and black floors
 void drawMap2D()
 {
+  // glColor3f(0, 1, 1);
+  // glBegin(GL_QUADS);
+  // glVertex2i(0, 0);
+  // glVertex2i(TOTAL_WIDTH, 0);
+  // glVertex2i(TOTAL_WIDTH, (int)(TOTAL_HEIGHT / 2));
+  // glVertex2i(0, (int)(TOTAL_HEIGHT / 2));
+  // glEnd();
+
+  // glColor3f(0, 0, 1);
+  // glBegin(GL_QUADS);
+  // glVertex2i(0, (int)(TOTAL_HEIGHT / 2));
+  // glVertex2i(TOTAL_WIDTH, (int)(TOTAL_HEIGHT / 2));
+  // glVertex2i(TOTAL_WIDTH, TOTAL_HEIGHT);
+  // glVertex2i(0, TOTAL_HEIGHT);
+  // glEnd();
+
   int gridMapSize = mapSize;
   int x, y, xo, yo;
   for (y = 0; y < mapY; y++)
@@ -585,6 +587,9 @@ void drawRays3D()
     rayAngle -= 2 * PI;
   }
 
+  glPointSize(2.0f);
+  glBegin(GL_POINTS);
+
   // * Cast n rays
   for (r = 0; r < 60; r++)
   {
@@ -804,8 +809,12 @@ void drawRays3D()
     // The further away, the larger the distance and the shorter the final line
     // height will be.
     float lineHeight = (mapSize * gameHeight) / disT;
+    float textureYstep = mapSize / (float)lineHeight;
+    float textureYoffset = 0;
+
     if (lineHeight > gameHeight)
     {
+      textureYoffset = (lineHeight - gameHeight) / 2.0;
       lineHeight = gameHeight;
     }
 
@@ -821,16 +830,56 @@ void drawRays3D()
 
     // Calculate dynamic column width and horizontal starting offset
     float rayWidth = (float)gameWidth / 60.0f;
+    int xStart = (int)floorf(r * rayWidth);
+    int xEnd = (int)floorf((r + 1) * rayWidth);
     float rayX3D = MAP_WIDTH + GAP + (r * rayWidth);
 
+    float shade = 1;
+    glColor3f(0, 0.8, 0);
+    if (distanceVert < distanceHor)
+    {
+      shade = 0.5;
+      rayX = vx;
+      rayY = vy;
+      distanceHor = distanceVert;
+      glColor3f(0, 0.6, 0);
+    }
+
     // * Draw the "wall" line
-    // Draw solid wall column using QUADS instead of GL_LINES
-    glBegin(GL_QUADS);
-    glVertex2f(rayX3D, lineOffset);
-    glVertex2f(rayX3D + rayWidth, lineOffset);
-    glVertex2f(rayX3D + rayWidth, lineOffset + lineHeight);
-    glVertex2f(rayX3D, lineOffset + lineHeight);
-    glEnd();
+
+    int x, y;
+    int textureX;
+
+    if (shade == 1) // North-south walls (PI -> (2 * PI))
+    {
+
+      textureX = (int)(rayX / 2.0) % mapSize;
+
+      if (rayAngle < PI) // South walls
+      {
+        textureX = mapSize - 1 - textureX;
+      }
+    }
+    else // East-west walls (PI2 -> PI3)
+    {
+      textureX = (int)(rayY / 2.0) % mapSize;
+      if (rayAngle > PI2 && rayAngle < PI3) // West
+      {
+        textureX = mapSize - 1 - textureX;
+      }
+    }
+
+    for (x = xStart; x < xEnd; x++)
+    {
+      float textureY = textureYoffset * textureYstep;
+      for (y = 0; y < lineHeight; y++)
+      {
+        float c = All_Textures[((int)textureY * mapSize) + textureX] * shade;
+        glColor3f(c, c, c);
+        glVertex2i(MAP_WIDTH + GAP + x, (int)(y + lineOffset));
+        textureY += textureYstep;
+      }
+    }
 
     // * Increase the ray angle to draw the next ray
     rayAngle += DR;
@@ -843,6 +892,7 @@ void drawRays3D()
       rayAngle -= 2 * PI;
     }
   }
+  glEnd();
 }
 
 // * Draw ceiling
@@ -1078,7 +1128,21 @@ void ButtonUp(unsigned char key, int x, int y)
 // * Window resizing
 void resize(int w, int h)
 {
-  glutReshapeWindow(1024, 512);
+  // Prevent division by zero
+  if (h == 0)
+    h = 1;
+
+  // Map the orthographic scene bounds to fill the entire window frame
+  glViewport(0, 0, w, h);
+
+  glMatrixMode(GL_PROJECTION);
+  glLoadIdentity();
+
+  // Set logical coordinate space: (left, right, bottom, top)
+  gluOrtho2D(0, TOTAL_WIDTH, TOTAL_HEIGHT, 0);
+
+  glMatrixMode(GL_MODELVIEW);
+  glLoadIdentity();
 }
 
 // * Check for key presses and move the "player" accordingly
@@ -1091,7 +1155,7 @@ void init()
 
   // Sets the window to be 2D at a given size
   // gluOrtho2D(0, 1024, 512, 0);
-  gluOrtho2D(0, TOTAL_WIDTH, TOTAL_HEIGHT, 0);
+  // gluOrtho2D(0, TOTAL_WIDTH, TOTAL_HEIGHT, 0);
 
   // Spawn player centered in grid tile (1, 1)
   playerX = 1.5f * mapSize;
@@ -1109,7 +1173,7 @@ int main(int argc, char *argv[])
   glutInit(&argc, argv);
   glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA);
   // glutInitWindowSize(TOTAL_WIDTH, TOTAL_HEIGHT);
-  glutInitWindowSize(1024, 510);
+  glutInitWindowSize(1024, 512);
 
   // Initialize the window to the center of the screen
   glutInitWindowPosition(200, 200);