From 80489b02d737848395506b218b27b86dc116d8b4 Mon Sep 17 00:00:00 2001
From: davidovski <david@davidovski.xyz>
Date: Sun, 9 Jul 2023 22:47:25 +0100
Subject: use texture to pass tilemap

---
 tiled.c    |  58 +++++++++++++++++++++++++++++++++++++++-------------------
 tiled.glsl |   5 +++--
 tiled.png  | Bin 0 -> 875 bytes
 tiles.png  | Bin 875 -> 0 bytes
 4 files changed, 42 insertions(+), 21 deletions(-)
 create mode 100644 tiled.png
 delete mode 100644 tiles.png

diff --git a/tiled.c b/tiled.c
index 64118bb..220043d 100644
--- a/tiled.c
+++ b/tiled.c
@@ -1,4 +1,6 @@
 #include <raylib.h>
+#include <stdlib.h>
+#include <stdio.h>
 #include <wctype.h>
 
 #define SCREEN_W 1280
@@ -7,40 +9,61 @@
 #define MAP_W 16
 #define MAP_H 4
 
-const int tilemap[MAP_H][MAP_W] = {
-    {0, 0, 0, 0, 0, 0, 3, 3, 3, 0, 0, 0, 0, 0, 0, 0,},
-    {0, 3, 3, 0, 0, 3, 1, 1, 1, 3, 0, 0, 0, 0, 0, 0,},
-    {3, 1, 1, 3, 3, 1, 2, 2, 2, 1, 3, 3, 3, 0, 0, 3,},
-    {1, 2, 2, 1, 1, 2, 4, 4, 4, 2, 1, 1, 1, 3, 3, 1,}
+const int tilemap[MAP_H * MAP_W] = {
+   0, 0, 0, 0, 0, 0, 3, 3, 3, 0, 0, 0, 0, 0, 0, 0,
+   0, 3, 3, 0, 0, 3, 1, 1, 1, 3, 0, 0, 0, 0, 0, 0,
+   3, 1, 1, 3, 3, 1, 2, 2, 2, 1, 3, 3, 3, 0, 0, 3,
+   1, 2, 2, 1, 1, 2, 4, 4, 4, 2, 1, 1, 1, 3, 3, 1
 };                          
 
 const int atlasSize[2] = {2, 2};
 
+Texture2D processTilemapTexture(const int * tilemap, int width, int height) {
+    Color *pixels = (Color*) malloc(width * height * sizeof(Color));
+
+    for (int y = 0; y < height; y++) {
+        for (int x = 0; x < width; x++) {
+            int tile = tilemap[y*width + x];
+            pixels[y*width + x] = (Color){
+                (int) tile, 0, 0, 0
+            };
+        }
+    }
+
+    Image checkedIm = {
+        .data = pixels,
+        .width = width,
+        .height = height,
+        .format = PIXELFORMAT_UNCOMPRESSED_R8G8B8A8,
+        .mipmaps = 1
+    };
+
+    Texture2D checked = LoadTextureFromImage(checkedIm);
+    UnloadImage(checkedIm);
+
+    return checked;
+}
+
 int main() {
     InitWindow(SCREEN_W, SCREEN_H, "tiled");
 
     Shader shader = LoadShader(0, "tiled.glsl");
 
+    Texture2D processedTilemap = processTilemapTexture(tilemap, MAP_W, MAP_H);
+    Texture atlas = LoadTexture("tiled.png");
     RenderTexture2D target = LoadRenderTexture(SCREEN_W, SCREEN_H);
 
     float resolution[2] = {SCREEN_W, SCREEN_H};
     float offset[2] = {0, 0};
     float zoom = 16.0f;
-    Texture atlas = LoadTexture("tiles.png");
+
     int resolutionLoc = GetShaderLocation(shader, "resolution");
     int locationLoc = GetShaderLocation(shader, "offset");
     int zoomLoc = GetShaderLocation(shader, "zoom");
     int atlasSizeLoc = GetShaderLocation(shader, "atlasSize");
 
-    int tilemapLoc[MAP_H][MAP_W] = {};
-    for (int x = 0; x < MAP_W; x++) {
-      for (int y = 0; y < MAP_H; y++) {
-        tilemapLoc[y][x] =
-            GetShaderLocation(shader, TextFormat("tilemap[%d][%d]", y, x));
-      }
-    }
-
     int textureLoc = GetShaderLocation(shader, "texture1");
+    int tilemapLoc = GetShaderLocation(shader, "texture2");
 
     while (!WindowShouldClose()) {
 		if (IsKeyDown(KEY_UP)) offset[1] += zoom * 0.01f;
@@ -55,11 +78,6 @@ int main() {
         SetShaderValue(shader, locationLoc, &offset, SHADER_UNIFORM_VEC2);
         SetShaderValue(shader, zoomLoc, &zoom, SHADER_UNIFORM_FLOAT);
         SetShaderValue(shader, atlasSizeLoc, &atlasSize, SHADER_UNIFORM_IVEC2);
-        for (int x = 0; x < MAP_W; x++) {
-        for (int y = 0; y < MAP_H; y++) {
-            SetShaderValue(shader, tilemapLoc[y][x], &tilemap[y][x], SHADER_UNIFORM_INT);
-        }
-        }
 
         BeginDrawing();
 
@@ -71,10 +89,12 @@ int main() {
 
         BeginShaderMode(shader);
             SetShaderValueTexture(shader, textureLoc, atlas);
+            SetShaderValueTexture(shader, tilemapLoc, processedTilemap);
 
             // draw the base image to texture0
             DrawTexture(target.texture, 0, 0, WHITE);
         EndShaderMode();
+            DrawTexture(processedTilemap, 0, 0, WHITE);
 
             DrawText(TextFormat("FPS: %d", GetFPS()), 12, 12, 24, DARKGRAY);
 
diff --git a/tiled.glsl b/tiled.glsl
index 9d00690..3ec1c66 100644
--- a/tiled.glsl
+++ b/tiled.glsl
@@ -10,12 +10,12 @@ in vec4 fragColor;
 
 uniform sampler2D texture0;
 uniform sampler2D texture1;
+uniform sampler2D texture2;
 
 uniform vec2 resolution;
 uniform vec2 offset;
 uniform float zoom;
 uniform ivec2 atlasSize;
-uniform int tilemap[MAP_H][MAP_W];
 
 out vec4 finalColor;
 
@@ -65,6 +65,7 @@ void main() {
         finalColor = none;
     } else {
         vec2 position = mod(uv, 1);
-        finalColor = tile(position, tilemap[tilemapPos.y][tilemapPos.x]);
+        int tileIndex = int(256*texelFetch(texture2, tilemapPos, 0).r);
+        finalColor = tile(position, tileIndex);
     }
 }
diff --git a/tiled.png b/tiled.png
new file mode 100644
index 0000000..455750a
Binary files /dev/null and b/tiled.png differ
diff --git a/tiles.png b/tiles.png
deleted file mode 100644
index 455750a..0000000
Binary files a/tiles.png and /dev/null differ
-- 
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