From e161fffc0cec8f516a8091186fbed4489361e2e8 Mon Sep 17 00:00:00 2001
From: IlyaShurupov <ilusha@workspace.com>
Date: Fri, 12 Apr 2024 16:27:21 +0300
Subject: [PATCH] tmp

---
 GeometryEditor2D/private/Render.cpp | 56 ++++++++++++++++++++---------
 1 file changed, 40 insertions(+), 16 deletions(-)

diff --git a/GeometryEditor2D/private/Render.cpp b/GeometryEditor2D/private/Render.cpp
index 5d18f1c..b1aee47 100644
--- a/GeometryEditor2D/private/Render.cpp
+++ b/GeometryEditor2D/private/Render.cpp
@@ -5,32 +5,56 @@
 using namespace tp;
 
 struct Shape {
-	float buffer[6] = {
-		0, 0, 1, 0, 0, 1,
+	float buffer[8] = {
+		1, 1, 1, 0, 0, 0, //
+		0, 1,             // 1, 1, 0, 0,
 	};
 
-	GLuint vbo_id = 0;
-	GLuint vbo_len = 6;
+	unsigned int indices[6] = { 0, 1, 3, 1, 2, 3 };
+
+	GLuint VAO = 0;
+	GLuint VBO = 0;
+	GLuint EBO = 0;
 
 	Shape() {
-		glGenBuffers(1, &vbo_id);
-		glBindBuffer(GL_ARRAY_BUFFER, vbo_id);
-		glBufferData(GL_ARRAY_BUFFER, sizeof(buffer), buffer, GL_STATIC_COPY);
-	}
+		glGenVertexArrays(1, &VAO);
+		glGenBuffers(1, &VBO);
+		glGenBuffers(1, &EBO);
 
-	void drawCall() {
-		glBindBuffer(GL_ARRAY_BUFFER, vbo_id);
+		glBindVertexArray(VAO);
+
+		glBindBuffer(GL_ARRAY_BUFFER, VBO);
+		glBufferData(GL_ARRAY_BUFFER, sizeof(buffer), buffer, GL_STATIC_DRAW);
+
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
+		glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW);
 
 		glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(float), nullptr);
 		glEnableVertexAttribArray(0);
 
-		glDrawArrays(GL_TRIANGLES, 0, 3);
-
-		glDisableVertexAttribArray(0);
+		// glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+		glBindBuffer(GL_ARRAY_BUFFER, 0);
 		glBindVertexArray(0);
 	}
 
-	~Shape() { glDeleteBuffers(1, &vbo_id); }
+	void drawCall() {
+		const auto numPoints = sizeof(buffer) / (2 * sizeof(float));
+
+		glBindVertexArray(VAO);
+
+		// glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
+		auto num = sizeof(indices) / sizeof(indices[0]);
+		glDrawElements(GL_TRIANGLES, num, GL_UNSIGNED_INT, nullptr);
+
+		// glDrawArrays(GL_TRIANGLES, 0, sizeof(buffer) / (2 * sizeof(float)));
+
+		// glBindVertexArray(0);
+	}
+
+	~Shape() {
+		glDeleteBuffers(1, &VBO);
+		glDeleteVertexArrays(1, &VAO);
+	}
 };
 
 Render::Render(Vec2F renderResolution) :
@@ -61,14 +85,14 @@ void Render::render(const Geometry& geometry, Vec2F size) {
 		static auto uniform_scale = mDefaultShader.getu("Viewport");
 
 		RGBA col = { 0, 0, 1.f, 1.f };
-		RectF viewport = { 0.0f, 0.0f, 1.f, 1.f };
+		RectF viewport = { -1.0f, -1.0f, 3.f, 3.f };
 		viewport.w = viewport.z * (size.y / size.x);
 
 		glUniform4fv(uniform_color, 1, &col.r);
 		glUniform4fv(uniform_scale, 1, &viewport.x);
 
 		shape.drawCall();
-		
+
 		mDefaultShader.unbind();
 	}