From 56fbc89983e770b98309fe2fba40abe5aaf0ee58 Mon Sep 17 00:00:00 2001
From: hkc <hatkidchan@gmail.com>
Date: Fri, 14 Oct 2022 08:49:58 +0300
Subject: [PATCH] Hot reloading and somewhat working but SLOW shader

---
 src/asciify.frag | 36 ++++++++++++++++++++++++++++++---
 src/main.c       | 52 ++++++++++++++++++++++++++++++++++--------------
 2 files changed, 70 insertions(+), 18 deletions(-)

diff --git a/src/asciify.frag b/src/asciify.frag
index d0fea0b..cb288bf 100644
--- a/src/asciify.frag
+++ b/src/asciify.frag
@@ -16,12 +16,42 @@ void main()
 {
   vec2 screenSize = fontSize * charactersXY;
   vec2 pixelCoord = floor(fragTexCoord * screenSize);
-  vec2 symbol = floor(pixelCoord / fontSize) / screenSize;
-  vec2 inSymbol = mod(pixelCoord, fontSize) / fontSize;
+  vec2 symbol = floor(pixelCoord / fontSize);
+  vec2 inSymbol = mod(pixelCoord, fontSize) / fontSize / vec2(16., 8.);
   vec4 texelColor = vec4(0.0, 0.0, 0.0, 1.0);
 
-  texelColor.rgb = texture(texture0, symbol * fontSize).rgb;
+  //texelColor.rgb = texture(texture0, symbol * fontSize).rgb;
+  //texelColor.rg = texture(fontAtlas, symbol + inSymbol / vec2(16., 8.)).rg;
+  //texelColor.rg = symbol + inSymbol / vec2(64., 32.);
 
+  vec3 smallest_diff = vec3(99999999999.), diff = vec3(0.);
+  ivec2 probeSym = ivec2(0), closestSymbol = ivec2(5, -3);
+  for (probeSym.y = 0; probeSym.y < 8; probeSym.y++) {
+    for (probeSym.x = 0; probeSym.x < 16; probeSym.x++) {
+      vec2 charPosition = probeSym / vec2(16., 8.), inCharPosition = vec2(0.);
+      diff = vec3(0.);
+      for (inCharPosition.y = 0.; inCharPosition.y < 1.0; inCharPosition.y += 1. / fontSize.y) {
+        for (inCharPosition.x = 0.; inCharPosition.x < 1.0; inCharPosition.x += 1. / fontSize.x) {
+          vec3 charRGB = texture(fontAtlas, (inCharPosition + probeSym) / vec2(16., 8.)).rgb,
+               srcRGB = texture(texture0, pixelCoord / screenSize).rgb;
+          diff = diff + abs(srcRGB - charRGB);
+        }
+      }
+      if (length(diff) < length(smallest_diff)) {
+        smallest_diff = diff;
+        closestSymbol = probeSym;
+      }
+    }
+  }
+  texelColor.rg = texture(fontAtlas, inSymbol + closestSymbol / vec2(16., 8.)).rg;
+
+#if 0
+  if (fragTexCoord.x >= 0.5)
+    finalColor = texture(texture0, fragTexCoord);
+  else
+    finalColor = texelColor;
+#else
   finalColor = texelColor;
+#endif
 }
 
diff --git a/src/main.c b/src/main.c
index 3778f79..fafcd38 100644
--- a/src/main.c
+++ b/src/main.c
@@ -32,9 +32,13 @@ int main(int argc, char **argv) {
   InitWindow(320, 240, "Loading...");
   SetTargetFPS(60);
 
+  char *font_path = "unscii-16-full.ttf",
+       *shader_path = "./src/asciify.frag";
+  if (argc >= 2) font_path = argv[1];
+
   int font_size = 16, chars_x = 160, chars_y = 50;
 
-  Font font = LoadFontEx("unscii-16-full.ttf", font_size, NULL, 256);
+  Font font = LoadFontEx(font_path, font_size, NULL, 256);
   Vector2 glyphSize = MeasureTextEx(font, "A", font_size, 0);
   Image img_atlas = GenImageColor(glyphSize.x * 16, glyphSize.y * 8, BLACK);
 
@@ -51,6 +55,8 @@ int main(int argc, char **argv) {
     }, WHITE);
   }
 
+  ImageFlipVertical(&img_atlas);
+
   Texture2D tex_atlas = LoadTextureFromImage(img_atlas);
   int wsize_x = chars_x * glyphSize.x, wsize_y = chars_y * glyphSize.y;
   SetWindowMinSize(glyphSize.x * 40, glyphSize.y * 12);
@@ -71,18 +77,8 @@ int main(int argc, char **argv) {
     .position.z = 50.0,
   };
 
-  Shader shd_asciify = LoadShader(NULL, "./src/asciify.frag");
-  int locAtlas = GetShaderLocation(shd_asciify, "fontAtlas");
-
-  {
-    float tmp[2];
-
-    tmp[0] = glyphSize.x; tmp[1] = glyphSize.y;
-    printf("glyph size: %fx%f\n", tmp[0], tmp[1]);
-    SetShaderValue(shd_asciify, GetShaderLocation(shd_asciify, "fontSize"), tmp, SHADER_UNIFORM_VEC2);
-    tmp[0] = chars_x; tmp[1] = chars_y;
-    SetShaderValue(shd_asciify, GetShaderLocation(shd_asciify, "charactersXY"), tmp, SHADER_UNIFORM_VEC2);
-  }
+  Shader shd_asciify;
+  long shaderLastModified = 0, shaderModified = -1;
 
   SetCameraMode(cam, CAMERA_FREE);
 
@@ -102,6 +98,27 @@ int main(int argc, char **argv) {
       SetShaderValue(shd_asciify, GetShaderLocation(shd_asciify, "charactersXY"), tmp, SHADER_UNIFORM_VEC2);
     }
 
+    if ((frame % 10) == 0) {
+      shaderModified = GetFileModTime(shader_path);
+    }
+
+    if (shaderModified != shaderLastModified)
+    {
+      printf("Recompiling...\n");
+      shd_asciify = LoadShader(NULL, shader_path);
+
+
+      float tmp[2];
+
+      tmp[0] = glyphSize.x; tmp[1] = glyphSize.y;
+      SetShaderValue(shd_asciify, GetShaderLocation(shd_asciify, "fontSize"), tmp, SHADER_UNIFORM_VEC2);
+
+      tmp[0] = chars_x; tmp[1] = chars_y;
+      SetShaderValue(shd_asciify, GetShaderLocation(shd_asciify, "charactersXY"), tmp, SHADER_UNIFORM_VEC2);
+      shaderLastModified = shaderModified;
+    }
+
+
     if (IsKeyDown(KEY_LEFT_SHIFT) && IsKeyPressed(KEY_F)) {
       SetWindowSize(wsize_x, wsize_y);
     }
@@ -137,8 +154,13 @@ int main(int argc, char **argv) {
 
     ClearBackground(RED);
     DrawRectangle(0, 0, wsize_x, wsize_y, BLACK);
-    if (shading) BeginShaderMode(shd_asciify);
-    SetShaderValueTexture(shd_asciify, locAtlas, tex_atlas);
+
+    if (shading) {
+      BeginShaderMode(shd_asciify);
+      int locAtlas = GetShaderLocation(shd_asciify, "fontAtlas");
+      SetShaderValueTexture(shd_asciify, locAtlas, tex_atlas);
+    }
+
     DrawTexturePro(framebuffer.texture, (Rectangle){
       0, 0, wsize_x, -wsize_y
     }, (Rectangle){