Fix sun making everything transperent

and sun has beautiful gradient

src/App.cpp

@@ -21,7 +21,7 @@ void App::init(int screenWidth, int screenHeight)
   canvas.newGen(canvasTexure[0]);
   canvas.newGen(canvasTexure[1]);
 
-  float posY = (screenHeight - screenWidth) / 2;
+  float posY = (screenHeight - screenWidth) / 2.0f;
   destA = {0, posY, (float)screenWidth, (float)screenWidth};
   destB = destA;
 }
@@ -69,4 +69,5 @@ void App::deinit()
   {
       UnloadRenderTexture(canvasTexure[i]);
   }
+  canvas.deinit();
 }

src/canvas/BackGround.cpp

@@ -10,6 +10,12 @@
 void BackGround::init(int size)
 {
   this->size = size;
+  sun.init();
+}
+
+void BackGround::deinit()
+{
+  sun.deinit();
 }
 
 void BackGround::newGen()
@@ -36,8 +42,8 @@ void BackGround::draw()
   {
     DrawRectangleGradientV(0, 0, size, size, ColorAdd(BackGroundColors::backGroundColor, 60), BackGroundColors::backGroundColor);
   }
-
-  drawMoon();
+  
+  drawSun();
   drawMounten(20, (int)(mounten1min * size), (int)(mounten1max * size), BackGroundColors::MountenColor1);
   drawMounten(21, (int)(mounten2min * size), (int)(mounten2max * size), BackGroundColors::MountenColor2);
   drawMounten(23, (int)(mounten3min * size), (int)(mounten3max * size), BackGroundColors::MountenColor3);
@@ -83,18 +89,13 @@ void BackGround::drawStarts()
   rlSetTexture(0);
 }
 
-void BackGround::drawMoon()
+void BackGround::drawSun()
 {
   int r = ((m_moon.size * (maxSizeOfMoon - minSizeOfMoon)) + minSizeOfMoon) * size;
   int xpos = Lerp(size * moonXOffset, size - size * moonXOffset, m_moon.x);
   int ypos = Lerp(size * moonXOffset, maxYPosOfMoon * size, m_moon.y);
 
-  int ring1 = (float)r * bigRingRatio;
-  int ring2 = (float)r * smallRingRatio;
-
-  DrawCircle(xpos, ypos, r + ring1, ColorLerp(BackGroundColors::backGroundColor, BackGroundColors::moonColor, bigRingBlend));
-  DrawCircle(xpos, ypos, r + ring2, ColorLerp(BackGroundColors::backGroundColor, BackGroundColors::moonColor, smallRingBlend));
-  DrawCircle(xpos, ypos, r, BackGroundColors::moonColor);
+  sun.draw(xpos, ypos, r);
 }
 
 void BackGround::drawMounten(size_t mountenSegments, int min, int max, Color color)

src/canvas/Canvas.cpp

@@ -16,3 +16,8 @@ void Canvas::newGen(RenderTexture2D& target)
 
   EndTextureMode();
 }
+
+void Canvas::deinit() 
+{
+  backGround.deinit();
+}

src/canvas/Sun.cpp

@@ -0,0 +1,70 @@
+#include "canvas/Sun.hpp"
+
+#include "Math.hpp"
+
+#include <raylib.h>
+#include <rlgl.h>
+
+const char* sun_shader = "#version 330\n\
+in vec2 fragTexCoord;\
+in vec4 fragColor;\
+out vec4 finalColor;\
+uniform vec3 color;\
+uniform float sun_radius;\
+uniform float start_transperency;\
+vec2 offset = vec2(1.0f, 1.0f);\
+float sun_end = 1.0f;\
+void main()\
+{\
+    offset.x -= fragTexCoord.x * 2;\
+    offset.y -= fragTexCoord.y * 2;\
+    float radius = length(offset);\
+    if (radius < sun_radius) {\
+        finalColor = vec4(color, 1.0f);\
+    }\
+    else if (radius < sun_end) {\
+        float gradient = radius;\
+        gradient -= sun_radius;\
+        gradient = gradient / (sun_end - sun_radius) * start_transperency;\
+        finalColor = vec4(color, start_transperency - gradient);\
+    }\
+    else {\
+        finalColor = vec4(color, 0.0f);\
+    }\
+}";
+
+void Sun::init()
+{
+  shader = LoadShaderFromMemory(0, sun_shader);
+  target = LoadRenderTexture(sizeTexute, sizeTexute);
+
+  sun_radius_loc = GetShaderLocation(shader, "sun_radius");
+  SetShaderValue(shader, sun_radius_loc, &sun_radius, SHADER_UNIFORM_FLOAT);
+
+  start_transperency_loc = GetShaderLocation(shader, "start_transperency");
+  SetShaderValue(shader, start_transperency_loc, &start_transperency, SHADER_UNIFORM_FLOAT);
+
+  colorLoc = GetShaderLocation(shader, "color");
+  SetShaderValue(shader, colorLoc, c, SHADER_UNIFORM_VEC3);
+
+  // resitev da ne postane tekstura okoli sonca transparentna in da se ne vidi nasledna slika 
+  // https://github.com/raysan5/raylib/issues/3820
+  rlSetBlendFactorsSeparate(RL_SRC_ALPHA, RL_ONE_MINUS_SRC_ALPHA, RL_ONE, RL_ONE, RL_FUNC_ADD, RL_MAX);
+}
+
+void Sun::deinit()
+{
+  UnloadShader(shader);
+  UnloadRenderTexture(target);
+}
+
+void Sun::draw(float x, float y, float size)
+{
+  Rectangle dest = { x-size, y - size, size * 2, size * 2};
+  // zgorni komentar da se mesanje barv oklopi pravilno
+  BeginBlendMode(RL_BLEND_CUSTOM_SEPARATE);
+    BeginShaderMode(shader);
+    drawTexureWithRotation(target, dest, 0.0f);
+    EndShaderMode();
+  EndBlendMode();
+}