Create function_-_scanlinefill_bresenhamline.c

function_-_scanlinefill_bresenhamline.c

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+
+#include "raylib.h"
+
+#define MAP_WIDTH 100
+#define MAP_HEIGHT 100
+
+int map[MAP_HEIGHT][MAP_WIDTH];
+
+void scanlinefill(int x, int y,int value);
+void mapline(int x1, int y1, int x2, int y2,int value);
+
+
+int main(void)
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    const int screenWidth = 800;
+    const int screenHeight = 450;
+
+    InitWindow(screenWidth, screenHeight, "raylib example.");
+ 
+    SetTargetFPS(60);               // Set our game to run at 60 frames-per-second
+    //--------------------------------------------------------------------------------------
+    mapline(0,0,MAP_WIDTH,MAP_HEIGHT,1);
+    scanlinefill(50,48,1);
+
+    // Main game loop
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        
+        
+        //----------------------------------------------------------------------------------
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+            ClearBackground(RAYWHITE);
+                
+            for(int y=0;y<MAP_HEIGHT;y++){
+            for(int x=0;x<MAP_WIDTH;x++){
+                if(map[y][x]==1){
+                    DrawRectangle(x*2,y*2,2,2,RED);
+                }
+            }}
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+    CloseWindow();        // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+
+
+}
+
+//
+// scan line fill(flood) the map array if the value is 0 with value.
+//
+//
+void scanlinefill(int x, int y,int value){
+    if(x<0 || x>=MAP_WIDTH || y<0 || y>=MAP_HEIGHT)return;
+    if(map[y][x]==value)return;
+    int x2=x;
+    while(x2>-1 && map[y][x2]==0){
+        map[y][x2]=value;
+        scanlinefill(x2,y-1,value);
+        scanlinefill(x2,y+1,value);
+        x2--;
+    }
+    x2=x+1;
+    while(x2<MAP_WIDTH && map[y][x2]==0){
+        map[y][x2]=value;
+        scanlinefill(x2,y-1,value);
+        scanlinefill(x2,y+1,value);
+        x2++;
+    }
+    
+}
+
+//
+// Bresenham line inside map[][] array.
+//
+void mapline(int x1, int y1, int x2, int y2,int value){
+    int dx;
+    int dy;
+    int sx;
+    int sy;
+    int e;
+    dx = abs(x2 - x1);
+    sx = -1;
+    if(x1 < x2)sx = 1;
+    dy = abs(y2 - y1);
+    sy = -1;
+    if(y1 < y2)sy = 1;
+    if(dx < dy){
+      e = dx / 2; 
+    }else{ 
+      e = dy / 2;          
+    }
+    bool exitloop=false;
+    while(exitloop == false){
+        //SetColor 255,255,255
+        //DrawPoint x1,y1
+        if(x1>-1 && x1<MAP_WIDTH && y1>-1 && y1<MAP_HEIGHT)map[x1][y1]=value;
+ 
+        if(x1 == x2){ 
+            if(y1 == y2){
+                exitloop = true;
+            }
+        }
+        if(dx > dy){
+            x1 += sx;
+            e -= dy; 
+            if (e < 0){
+                e += dx;
+                y1 += sy;
+            }
+        }else{
+            y1 += sy; 
+            e -= dx;
+            if(e < 0){
+              e += dy;
+              x1 += sx;
+            }
+        }
+    }
+}