1 files changed, 70 insertions, 22 deletions

diff --git a/src/main.zig b/src/main.zig
index ce31e75..6d119af 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -4,6 +4,7 @@ const c = @import("c.zig");
 const debug_gl = @import("debug_gl.zig");
 const cfg = @import("config.zig");
 const out = @import("output.zig");
+const gl = @import("gl.zig");
 
 var window: *c.GLFWwindow = undefined;
 
@@ -22,60 +23,107 @@ pub fn main() !void {
     }
     defer c.glfwTerminate();
 
-    c.glfwWindowHint(c.GLFW_CONTEXT_VERSION_MAJOR, 3);
+    c.glfwWindowHint(c.GLFW_CONTEXT_VERSION_MAJOR, 4);
     c.glfwWindowHint(c.GLFW_CONTEXT_VERSION_MINOR, 2);
     c.glfwWindowHint(c.GLFW_OPENGL_FORWARD_COMPAT, c.GL_TRUE);
     c.glfwWindowHint(c.GLFW_OPENGL_DEBUG_CONTEXT, debug_gl.is_on);
     c.glfwWindowHint(c.GLFW_OPENGL_PROFILE, c.GLFW_OPENGL_CORE_PROFILE);
     c.glfwWindowHint(c.GLFW_DEPTH_BITS, 0);
-    c.glfwWindowHint(c.GLFW_STENCIL_BITS, 8);
+    c.glfwWindowHint(c.GLFW_STENCIL_BITS, 0);
     c.glfwWindowHint(c.GLFW_VISIBLE, c.GLFW_FALSE);
 
     window = c.glfwCreateWindow(config.width, config.height, "glsl-view", null, null) orelse {
         panic("unable to create window\n", .{});
     };
     defer c.glfwDestroyWindow(window);
-
+    
     c.glfwMakeContextCurrent(window);
     c.glfwSwapInterval(1);
 
-    c.glClearColor(0.0, 0.0, 0.0, 1.0);
-
-    // c.glEnable(c.GL_BLEND);
-    // c.glBlendFunc(c.GL_SRC_ALPHA, c.GL_ONE_MINUS_SRC_ALPHA);
-    // c.glPixelStorei(c.GL_UNPACK_ALIGNMENT, 1);
-
-    c.glViewport(0, 0, config.width, config.height);
-
-    debug_gl.assertNoError();
-
-    var outputs = try config.arena.allocator.alloc(*out.Output, config.outputs.len);
+    var constants = try gl.Constants.create(window);
+    defer constants.destroy();
+    
+    var outputs = try std.ArrayList(*out.Output).initCapacity(&config.arena.allocator, config.outputs.len);
+    defer outputs.deinit();
     for (config.outputs) |output_config, i| {
-        outputs[i] = out.Output.create(&config.arena.allocator, output_config, window);
+        try outputs.append(out.Output.create(&config.arena.allocator, output_config, &constants));
     }
-    defer for (outputs) |output| {
+    defer for (outputs.toSlice()) |output| {
         output.destroy(output);
     };
 
+    c.glfwMakeContextCurrent(window);
+    c.glClearColor(0.0, 0.0, 0.0, 1.0);
+
+    debug_gl.assertNoError();
+
     const start_time = c.glfwGetTime();
     var prev_time = start_time;
 
+    constants.normalizedQuad.bind(0);
+
+    debug_gl.assertNoError();
+
+    var redShader = try gl.ShaderProgram.create(
+        \\#version 330 core
+        \\
+        \\layout(location = 0) in vec2 position;
+        \\out vec2 uv;
+        \\
+        \\void main() {
+        \\  uv = position / 2.0 + 0.5;
+        \\  gl_Position = vec4(position, 0, 1);
+        \\}
+    ,
+        \\#version 330 core
+        \\
+        \\in vec2 uv;
+        \\out vec4 color;
+        \\
+        \\uniform float offset;
+        \\
+        \\void main() {
+        \\  color = vec4(mod(uv + offset, vec2(1)), 0, 1);
+        \\}
+    ,
+        null
+    );
+    defer redShader.destroy();
+
+    var fbo = try gl.FramebufferObject.create(config.width, config.height);
+    defer fbo.destroy();
+
+    var offset: f32 = 0;
+    
     while (c.glfwWindowShouldClose(window) == c.GL_FALSE) {
-        c.glClear(c.GL_COLOR_BUFFER_BIT | c.GL_DEPTH_BUFFER_BIT | c.GL_STENCIL_BUFFER_BIT);
+        c.glfwMakeContextCurrent(window);
+        c.glClear(c.GL_COLOR_BUFFER_BIT);
 
         const now_time = c.glfwGetTime();
         const elapsed = now_time - prev_time;
         prev_time = now_time;
+
+        fbo.bind();
+        c.glClear(c.GL_COLOR_BUFFER_BIT);
+        
+        redShader.bind();
+        offset += @floatCast(f32, elapsed / 4);
+        redShader.setUniformFloat(redShader.uniformLocation("offset"), offset);
+        constants.normalizedQuad.draw();
+        fbo.unbind();
         
-        for (outputs) |output| {
-            const close = output.update(output);
+        for (outputs.toSlice()) |output, i| {
+            const close = output.update(output, fbo.texture_id);
             if (close) {
-                c.glfwSetWindowShouldClose(window, c.GL_TRUE);
+                const removed = outputs.swapRemove(i);
+                removed.destroy(removed);
+                break;
             }
         }
 
-        c.glfwSwapBuffers(window);
-
+        if (outputs.len == 0)
+            break;
+        
         c.glfwPollEvents();
     }