From 62785bd02a94e9997f2ee893db5ac591d882840c Mon Sep 17 00:00:00 2001
From: Sander Hautvast <shautvast@gmail.com>
Date: Fri, 23 Oct 2020 22:14:38 +0200
Subject: [PATCH] version2, it zooms, and it has colors

---
 README.md                     |   2 +-
 mandelbrot.nimble             |   3 +-
 src/mandelbrot/mandelbrot.nim |  50 +++++-
 src/mandelbrot/shader.frag    | 300 ++++++++++++++++++++++++++++++++--
 4 files changed, 333 insertions(+), 22 deletions(-)

diff --git a/README.md b/README.md
index 54f8b14..d1eb944 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,3 @@
 * my first nim project https://nim-lang.org/
-* also: my first opengl project, manually translated from c++ from https://physicspython.wordpress.com/2020/02/16/visualizing-the-mandelbrot-set-using-opengl-part-1/
+* also: my first opengl project, manually translated from c++ found in https://physicspython.wordpress.com/2020/02/16/visualizing-the-mandelbrot-set-using-opengl-part-1/
 * works at least on my mac
diff --git a/mandelbrot.nimble b/mandelbrot.nimble
index da63733..bee6c18 100644
--- a/mandelbrot.nimble
+++ b/mandelbrot.nimble
@@ -1,5 +1,4 @@
 # Package
-
 version       = "0.1.0"
 author        = "Sander Hautvast"
 description   = "A mandelbrot fractal using opengl"
@@ -8,4 +7,4 @@ srcDir        = "src"
 bin           = @["mandelbrot/mandelbrot"]
 
 # Dependencies
-requires "nim >= 1.4.0", "nimgl >= 1.1.5"
\ No newline at end of file
+requires "nim >= 1.4.0", "nimgl >= 1.1.5", "glm >= 1.1.1"
\ No newline at end of file
diff --git a/src/mandelbrot/mandelbrot.nim b/src/mandelbrot/mandelbrot.nim
index 25c8879..2c137b8 100644
--- a/src/mandelbrot/mandelbrot.nim
+++ b/src/mandelbrot/mandelbrot.nim
@@ -1,14 +1,36 @@
 import nimgl/[glfw, opengl]
 
+
 var GLData: tuple[program, vertexShader, fragmentShader: uint32]
 const 
   WIN_WIDTH = 1000
   WIN_HEIGHT = 800
 
+var 
+  center_x = 0.0f
+  center_y = 0.0f
+  zoom:float64 = 1.0
+  dx=0.0
+  dy=0.0
+  zf=0.99
 
 proc keyProc(window: GLFWWindow, key: int32, scancode: int32, action: int32, mods: int32): void {.cdecl.} =
-  if key == GLFWKey.ESCAPE and action == GLFWPress:
-    window.setWindowShouldClose(true)
+#   if key == GLFWKey.ESCAPE and action == GLFWPress:
+#     window.setWindowShouldClose(true)
+
+
+# proc process_input(window: GLFWwindow)
+  if action == GLFWPress:
+    if key == GLFWKey.ESCAPE:
+      window.setWindowShouldClose(true)
+    if key == GLFWKey.UP:
+      dy += 0.001f
+    if key == GLFWKey.DOWN:
+      dy -= 0.001f
+    if key == GLFWKey.LEFT:
+      dx -= 0.001f
+    if key == GLFWKey.RIGHT:
+      dx += 0.001f;
 
 
 proc logShaderCompilationFailure(shader: uint32, shader_path:string) = 
@@ -61,6 +83,13 @@ proc initShaders(vertex_shader_path: string, fragment_shader_path: string) =
   if success == 0: logProgramLinkingError()
 
 
+proc set_float(name: string, value:float) =
+  glUniform1f(glGetUniformLocation(GLData.program, name.cstring()), value.cfloat());
+
+# proc set_vec4(name: string, vec: Vec4[float]) =
+#     glUniform4f(glGetUniformLocation(GLData.program, name.cstring()), vec[0].cfloat(), vec[1].cfloat(), vec[2].cfloat(), vec[3].cfloat())
+
+
 proc main() =
   assert glfwInit()
 
@@ -70,7 +99,7 @@ proc main() =
   glfwWindowHint(GLFWOpenglProfile, GLFW_OPENGL_CORE_PROFILE)
   glfwWindowHint(GLFWResizable, GLFW_FALSE)
 
-  let window = glfwCreateWindow(WIN_WIDTH, WIN_HEIGHT, "Simple Mandelbrot fractal")
+  let window = glfwCreateWindow(WIN_WIDTH, WIN_HEIGHT, "Mandelbrot fractal")
   assert window != nil
 
   discard window.setKeyCallback(keyProc)
@@ -116,10 +145,25 @@ proc main() =
     glClearColor(0.2, 0.2, 0.2, 0.5)
     glUseProgram(GLData.program)
     glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT)
+
+    zoom *= zf
+    if zf < 0.0: zf = 0.0
+    center_y += dy * zoom
+    if center_y > 1.0f: center_y = 1.0f
+    if center_y < -1.0f: center_y = -1.0f
+    center_x += dx * zoom
+    if center_x > 1.0f: center_x = 1.0f
+    if center_x < -1.0f: center_x = -1.0f
+
+    set_float("zoom", zoom)
+    set_float("center_x", center_x)
+    set_float("center_y", center_y)
+
     glBindVertexArray(mesh.vao)
     glDrawElements(GL_TRIANGLES, indices.len.cint, GL_UNSIGNED_INT, nil)
     window.swapBuffers()
     glfwPollEvents()
+   
 
   window.destroyWindow()
   glDeleteShader(GLData.vertexShader)
diff --git a/src/mandelbrot/shader.frag b/src/mandelbrot/shader.frag
index 2d1d03e..f74017a 100644
--- a/src/mandelbrot/shader.frag
+++ b/src/mandelbrot/shader.frag
@@ -1,35 +1,301 @@
 #version 410 core
 in vec4 gl_FragCoord;
  
-out vec4 frag_color;
+out vec4 fragColor;
+//out float gl_FragDepth;
  
-#define MAX_ITERATIONS 500
+uniform float center_x;
+uniform float center_y;
+uniform float zoom;
  
+#define MAX_ITERATIONS 600
+
+const vec3 colors[256] = vec3[256](
+vec3(0.0,0.0,0.0),
+vec3(128.0,0.0,0.0),
+vec3(0.0,128.0,0.0),
+vec3(128.0,128.0,0.0),
+vec3(0.0,0.0,128.0),
+vec3(128.0,0.0,128.0),
+vec3(0.0,128.0,128.0),
+vec3(192.0,192.0,192.0),
+vec3(128.0,128.0,128.0),
+vec3(255.0,0.0,0.0),
+vec3(0.0,255.0,0.0),
+vec3(255.0,255.0,0.0),
+vec3(0.0,0.0,255.0),
+vec3(255.0,0.0,255.0),
+vec3(0.0,255.0,255.0),
+vec3(255.0,255.0,255.0),
+vec3(0.0,0.0,0.0),
+vec3(0.0,0.0,95.0),
+vec3(0.0,0.0,135.0),
+vec3(0.0,0.0,175.0),
+vec3(0.0,0.0,215.0),
+vec3(0.0,0.0,255.0),
+vec3(0.0,95.0,0.0),
+vec3(0.0,95.0,95.0),
+vec3(0.0,95.0,135.0),
+vec3(0.0,95.0,175.0),
+vec3(0.0,95.0,215.0),
+vec3(0.0,95.0,255.0),
+vec3(0.0,135.0,0.0),
+vec3(0.0,135.0,95.0),
+vec3(0.0,135.0,135.0),
+vec3(0.0,135.0,175.0),
+vec3(0.0,135.0,215.0),
+vec3(0.0,135.0,255.0),
+vec3(0.0,175.0,0.0),
+vec3(0.0,175.0,95.0),
+vec3(0.0,175.0,135.0),
+vec3(0.0,175.0,175.0),
+vec3(0.0,175.0,215.0),
+vec3(0.0,175.0,255.0),
+vec3(0.0,215.0,0.0),
+vec3(0.0,215.0,95.0),
+vec3(0.0,215.0,135.0),
+vec3(0.0,215.0,175.0),
+vec3(0.0,215.0,215.0),
+vec3(0.0,215.0,255.0),
+vec3(0.0,255.0,0.0),
+vec3(0.0,255.0,95.0),
+vec3(0.0,255.0,135.0),
+vec3(0.0,255.0,175.0),
+vec3(0.0,255.0,215.0),
+vec3(0.0,255.0,255.0),
+vec3(95.0,0.0,0.0),
+vec3(95.0,0.0,95.0),
+vec3(95.0,0.0,135.0),
+vec3(95.0,0.0,175.0),
+vec3(95.0,0.0,215.0),
+vec3(95.0,0.0,255.0),
+vec3(95.0,95.0,0.0),
+vec3(95.0,95.0,95.0),
+vec3(95.0,95.0,135.0),
+vec3(95.0,95.0,175.0),
+vec3(95.0,95.0,215.0),
+vec3(95.0,95.0,255.0),
+vec3(95.0,135.0,0.0),
+vec3(95.0,135.0,95.0),
+vec3(95.0,135.0,135.0),
+vec3(95.0,135.0,175.0),
+vec3(95.0,135.0,215.0),
+vec3(95.0,135.0,255.0),
+vec3(95.0,175.0,0.0),
+vec3(95.0,175.0,95.0),
+vec3(95.0,175.0,135.0),
+vec3(95.0,175.0,175.0),
+vec3(95.0,175.0,215.0),
+vec3(95.0,175.0,255.0),
+vec3(95.0,215.0,0.0),
+vec3(95.0,215.0,95.0),
+vec3(95.0,215.0,135.0),
+vec3(95.0,215.0,175.0),
+vec3(95.0,215.0,215.0),
+vec3(95.0,215.0,255.0),
+vec3(95.0,255.0,0.0),
+vec3(95.0,255.0,95.0),
+vec3(95.0,255.0,135.0),
+vec3(95.0,255.0,175.0),
+vec3(95.0,255.0,215.0),
+vec3(95.0,255.0,255.0),
+vec3(135.0,0.0,0.0),
+vec3(135.0,0.0,95.0),
+vec3(135.0,0.0,135.0),
+vec3(135.0,0.0,175.0),
+vec3(135.0,0.0,215.0),
+vec3(135.0,0.0,255.0),
+vec3(135.0,95.0,0.0),
+vec3(135.0,95.0,95.0),
+vec3(135.0,95.0,135.0),
+vec3(135.0,95.0,175.0),
+vec3(135.0,95.0,215.0),
+vec3(135.0,95.0,255.0),
+vec3(135.0,135.0,0.0),
+vec3(135.0,135.0,95.0),
+vec3(135.0,135.0,135.0),
+vec3(135.0,135.0,175.0),
+vec3(135.0,135.0,215.0),
+vec3(135.0,135.0,255.0),
+vec3(135.0,175.0,0.0),
+vec3(135.0,175.0,95.0),
+vec3(135.0,175.0,135.0),
+vec3(135.0,175.0,175.0),
+vec3(135.0,175.0,215.0),
+vec3(135.0,175.0,255.0),
+vec3(135.0,215.0,0.0),
+vec3(135.0,215.0,95.0),
+vec3(135.0,215.0,135.0),
+vec3(135.0,215.0,175.0),
+vec3(135.0,215.0,215.0),
+vec3(135.0,215.0,255.0),
+vec3(135.0,255.0,0.0),
+vec3(135.0,255.0,95.0),
+vec3(135.0,255.0,135.0),
+vec3(135.0,255.0,175.0),
+vec3(135.0,255.0,215.0),
+vec3(135.0,255.0,255.0),
+vec3(175.0,0.0,0.0),
+vec3(175.0,0.0,95.0),
+vec3(175.0,0.0,135.0),
+vec3(175.0,0.0,175.0),
+vec3(175.0,0.0,215.0),
+vec3(175.0,0.0,255.0),
+vec3(175.0,95.0,0.0),
+vec3(175.0,95.0,95.0),
+vec3(175.0,95.0,135.0),
+vec3(175.0,95.0,175.0),
+vec3(175.0,95.0,215.0),
+vec3(175.0,95.0,255.0),
+vec3(175.0,135.0,0.0),
+vec3(175.0,135.0,95.0),
+vec3(175.0,135.0,135.0),
+vec3(175.0,135.0,175.0),
+vec3(175.0,135.0,215.0),
+vec3(175.0,135.0,255.0),
+vec3(175.0,175.0,0.0),
+vec3(175.0,175.0,95.0),
+vec3(175.0,175.0,135.0),
+vec3(175.0,175.0,175.0),
+vec3(175.0,175.0,215.0),
+vec3(175.0,175.0,255.0),
+vec3(175.0,215.0,0.0),
+vec3(175.0,215.0,95.0),
+vec3(175.0,215.0,135.0),
+vec3(175.0,215.0,175.0),
+vec3(175.0,215.0,215.0),
+vec3(175.0,215.0,255.0),
+vec3(175.0,255.0,0.0),
+vec3(175.0,255.0,95.0),
+vec3(175.0,255.0,135.0),
+vec3(175.0,255.0,175.0),
+vec3(175.0,255.0,215.0),
+vec3(175.0,255.0,255.0),
+vec3(215.0,0.0,0.0),
+vec3(215.0,0.0,95.0),
+vec3(215.0,0.0,135.0),
+vec3(215.0,0.0,175.0),
+vec3(215.0,0.0,215.0),
+vec3(215.0,0.0,255.0),
+vec3(215.0,95.0,0.0),
+vec3(215.0,95.0,95.0),
+vec3(215.0,95.0,135.0),
+vec3(215.0,95.0,175.0),
+vec3(215.0,95.0,215.0),
+vec3(215.0,95.0,255.0),
+vec3(215.0,135.0,0.0),
+vec3(215.0,135.0,95.0),
+vec3(215.0,135.0,135.0),
+vec3(215.0,135.0,175.0),
+vec3(215.0,135.0,215.0),
+vec3(215.0,135.0,255.0),
+vec3(215.0,175.0,0.0),
+vec3(215.0,175.0,95.0),
+vec3(215.0,175.0,135.0),
+vec3(215.0,175.0,175.0),
+vec3(215.0,175.0,215.0),
+vec3(215.0,175.0,255.0),
+vec3(215.0,215.0,0.0),
+vec3(215.0,215.0,95.0),
+vec3(215.0,215.0,135.0),
+vec3(215.0,215.0,175.0),
+vec3(215.0,215.0,215.0),
+vec3(215.0,215.0,255.0),
+vec3(215.0,255.0,0.0),
+vec3(215.0,255.0,95.0),
+vec3(215.0,255.0,135.0),
+vec3(215.0,255.0,175.0),
+vec3(215.0,255.0,215.0),
+vec3(215.0,255.0,255.0),
+vec3(255.0,0.0,0.0),
+vec3(255.0,0.0,95.0),
+vec3(255.0,0.0,135.0),
+vec3(255.0,0.0,175.0),
+vec3(255.0,0.0,215.0),
+vec3(255.0,0.0,255.0),
+vec3(255.0,95.0,0.0),
+vec3(255.0,95.0,95.0),
+vec3(255.0,95.0,135.0),
+vec3(255.0,95.0,175.0),
+vec3(255.0,95.0,215.0),
+vec3(255.0,95.0,255.0),
+vec3(255.0,135.0,0.0),
+vec3(255.0,135.0,95.0),
+vec3(255.0,135.0,135.0),
+vec3(255.0,135.0,175.0),
+vec3(255.0,135.0,215.0),
+vec3(255.0,135.0,255.0),
+vec3(255.0,175.0,0.0),
+vec3(255.0,175.0,95.0),
+vec3(255.0,175.0,135.0),
+vec3(255.0,175.0,175.0),
+vec3(255.0,175.0,215.0),
+vec3(255.0,175.0,255.0),
+vec3(255.0,215.0,0.0),
+vec3(255.0,215.0,95.0),
+vec3(255.0,215.0,135.0),
+vec3(255.0,215.0,175.0),
+vec3(255.0,215.0,215.0),
+vec3(255.0,215.0,255.0),
+vec3(255.0,255.0,0.0),
+vec3(255.0,255.0,95.0),
+vec3(255.0,255.0,135.0),
+vec3(255.0,255.0,175.0),
+vec3(255.0,255.0,215.0),
+vec3(255.0,255.0,255.0),
+vec3(8.0,8.0,8.0),
+vec3(18.0,18.0,18.0),
+vec3(28.0,28.0,28.0),
+vec3(38.0,38.0,38.0),
+vec3(48.0,48.0,48.0),
+vec3(58.0,58.0,58.0),
+vec3(68.0,68.0,68.0),
+vec3(78.0,78.0,78.0),
+vec3(88.0,88.0,88.0),
+vec3(98.0,98.0,98.0),
+vec3(108.0,108.0,108.0),
+vec3(118.0,118.0,118.0),
+vec3(128.0,128.0,128.0),
+vec3(138.0,138.0,138.0),
+vec3(148.0,148.0,148.0),
+vec3(158.0,158.0,158.0),
+vec3(168.0,168.0,168.0),
+vec3(178.0,178.0,178.0),
+vec3(188.0,188.0,188.0),
+vec3(198.0,198.0,198.0),
+vec3(208.0,208.0,208.0),
+vec3(218.0,218.0,218.0),
+vec3(228.0,228.0,228.0),
+vec3(238.0,238.0,238.0)
+);
+
 int get_iterations()
 {
-    float real = (gl_FragCoord.x / 1080.0 - 1.2) * 1.5;
-    float imag = (gl_FragCoord.y / 1080.0 - 0.7) * 1.5 ;
+    double real = ((gl_FragCoord.x / 1000.0f - 1.2f) * zoom + center_x) * 1.5f;
+    double imag = ((gl_FragCoord.y / 800.0f - 0.7f) * zoom + center_y) * 1.5f;
  
+
     int iterations = 0;
-    float const_real = real;
-    float const_imag = imag;
+    double const_real = real;
+    double const_imag = imag;
  
     while (iterations < MAX_ITERATIONS)
     {
-        float tmp_real = real;
+        double tmp_real = real;
         real = (real * real - imag * imag) + const_real;
         imag = (2.0 * tmp_real * imag) + const_imag;
          
-        float dist = real * real + imag * imag;
-         
+        double dist = real * real + imag * imag;
+ 
         if (dist > 4.0)
-        break;
+            break;
  
         ++iterations;
     }
     return iterations;
 }
-
+ 
+ 
 vec4 return_color()
 {
     int iter = get_iterations();
@@ -38,12 +304,14 @@ vec4 return_color()
         gl_FragDepth = 0.0f;
         return vec4(0.0f, 0.0f, 0.0f, 1.0f);
     }
- 
-    float iterations = float(iter) / MAX_ITERATIONS;    
-    return vec4(0.0f, iterations, 0.0f, 1.0f);
+    int colorIndex = int((float(iter)/float(MAX_ITERATIONS))*256);
+    vec3 color = colors[colorIndex];
+    return vec4(color.x/256, color.y/256, color.z/256, 1.0);
+    
 }
  
 void main()
 {
-    frag_color = return_color();
-}
\ No newline at end of file
+    fragColor = return_color();
+}
+