From 4cfbf59ab53ede8eb39a8317c504e7cee889a827 Mon Sep 17 00:00:00 2001
From: realtradam <github@tradam.dev>
Date: Mon, 18 Apr 2022 02:28:17 -0400
Subject: rewrote shader to be more flexible

---
 shaders/test.fs | 31 ++++++++++++++-----------------
 src/main.zig    | 16 ++++++++++++----
 2 files changed, 26 insertions(+), 21 deletions(-)

diff --git a/shaders/test.fs b/shaders/test.fs
index 16cf7c3..cba5bfb 100644
--- a/shaders/test.fs
+++ b/shaders/test.fs
@@ -1,9 +1,11 @@
 #version 330
 
+#define PI 3.1415926538
 
 // Input vertex attributes (from vertex shader)
 in vec2 fragTexCoord;
 in vec4 fragColor;
+vec2 flipped = vec2(fragTexCoord.x, 1 - fragTexCoord.y);
 
 // Input uniform values
 uniform sampler2D texture0;
@@ -18,26 +20,21 @@ uniform float renderHeight;
 vec2 textureResolution = vec2(renderWidth, renderHeight);
 uniform float grid_size;
 //vec2 onePixel = vec2(1.0, 1.0) / textureResolution;
-vec2 pixelCoor = fragTexCoord * textureResolution;
+vec2 pixelCoor = flipped * textureResolution;
+
+float gridify(float coordinate, float spacing) {
+	return clamp(floor(((-cos( coordinate * 2 * PI)) / 2) + spacing), 0.0, 1.0);
+}
+
+float is_pixel(vec2 coordinate, float spacing) {
+	return gridify(coordinate.x, spacing) * gridify(coordinate.y, spacing);
+}
 
 void main()
 {
-	vec4 texelColor = vec4(0.0, 0.0, 0.0, 0.0);
-    // Texel color fetching from texture sampler
-	if ((mod(floor(pixelCoor.x), grid_size + 1.0) == grid_size) || (mod(floor(pixelCoor.y), grid_size + 1.0) == grid_size))
-	{
-		texelColor = vec4(0.0, 0.0, 0.0, 1.0);
-	}
-	else {
-	pixelCoor.y = -pixelCoor.y;
-	pixelCoor = pixelCoor / (grid_size + 1.0);
-		texelColor = texture(texture0, (pixelCoor /textureResolution));
-	}
-//if ((pix % 3) == 2)
-//black pixel
-//else
-//get color of floor(pix / 3)
-//end
+	//float is_pixel = gridify(pixelCoor.x, 1.0) * gridify(pixelCoor.y, 1.0);
+	vec4 texelColor = texture(texture0, flipped);
+	texelColor.rbg *= is_pixel(pixelCoor, grid_size);
 
     // NOTE: Implement here your fragment shader code
 
diff --git a/src/main.zig b/src/main.zig
index 63e98d6..ce49e14 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -8,7 +8,7 @@ const print = std.debug.print;
 const fs = std.fs;
 
 const screenWidth: u32 = 64 * 10;
-const screenHeight: u32 = (32 * 10) + 24;
+const screenHeight: u32 = (32 * 10) + 24 + 60;
 const RndGen = std.rand.DefaultPrng;
 var Rnd = RndGen.init(0);
 var chip8_screen: ray.RenderTexture = undefined;
@@ -16,7 +16,11 @@ var shader: ray.Shader = undefined;
 var swirl_center_loc: c_int = undefined;
 var renderPoint_renderWidth: c_int = undefined;
 var renderPoint_renderHeight: c_int = undefined;
-var shader_gridsize: f32 = 2.0;
+var shader_gridsizeLocation: c_int = undefined;
+var shader_gridsize: f32 = 1.0;
+var slider: f32 = 100;
+const slider_max: f32 = 150;
+const slider_min: f32 = 50;
 
 var swirl_center = [_]u32{ screenWidth / 2, screenHeight / 2 };
 
@@ -163,11 +167,15 @@ pub fn main() !void {
     chip8.load_game("roms/IBM_Logo.ch8");
 
     while (!ray.WindowShouldClose() and !exitWindow) {
+        shader_gridsize = slider / 100.0;
+        ray.SetShaderValue(shader, shader_gridsizeLocation, &shader_gridsize, ray.SHADER_UNIFORM_FLOAT);
         ray.BeginDrawing();
         defer ray.EndDrawing();
 
         exitWindow = ray.GuiWindowBox(ray.Rectangle{ .x = 0, .y = 0, .height = screenHeight, .width = screenWidth }, "CHIP-8");
 
+        slider = ray.GuiSlider(ray.Rectangle{ .x = 70, .y = 32 * 10 + 24 + 10, .width = 64 * 8, .height = 30 }, "Pixel Size", "", slider, 50, 150);
+
         if (delay == execute_delay) {
             chip8.emulate_cycles(1);
             delay = 0;
@@ -185,13 +193,13 @@ fn get_coords(x: u32, y: u32) u32 {
 
 fn setup_graphics() void {
     ray.InitWindow(screenWidth, screenHeight, "raylib [core] example - basic window");
-    chip8_screen = ray.LoadRenderTexture(64 * @floatToInt(c_int, shader_gridsize + 1), 32 * @floatToInt(c_int, shader_gridsize + 1));
+    chip8_screen = ray.LoadRenderTexture(64, 32);
     //shader = ray.LoadShader(0, "shaders/glsl330/swirl.fs");
     shader = ray.LoadShader(0, "shaders/test.fs");
     //swirl_center_loc = ray.GetShaderLocation(shader, "center");
     renderPoint_renderHeight = ray.GetShaderLocation(shader, "renderHeight");
     renderPoint_renderWidth = ray.GetShaderLocation(shader, "renderWidth");
-    var shader_gridsizeLocation = ray.GetShaderLocation(shader, "grid_size");
+    shader_gridsizeLocation = ray.GetShaderLocation(shader, "grid_size");
 
     var renderVar_renderWidth: f32 = @intToFloat(f32, chip8_screen.texture.width);
     var renderVar_renderHeight: f32 = @intToFloat(f32, chip8_screen.texture.height);
-- 
cgit v1.2.3