From ee06b834b9a09772b5b78b23f7e5a04429091eb2 Mon Sep 17 00:00:00 2001
From: miaurizius <maurice@miaurizius.de>
Date: Wed, 15 Apr 2026 23:08:28 +0200
Subject: [PATCH] added indexbuffer

---
 src/main.cpp | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index abb00af..88c2930 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -38,10 +38,23 @@ int main() {
 
     Vertex vertices[] = {
         Vertex{-0.5f, -0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f},
-        Vertex{0.0f, 0.5f, 0.0f, 0.0, 1.0f, 0.0f, 1.0f},
+        Vertex{-0.5f, 0.5f, 0.0f, 0.0, 1.0f, 0.0f, 1.0f},
         Vertex{0.5f, -0.5f, 0.0f, 0.0f, 0.0f, 1.0f, 1.0f},
+
+        Vertex{0.5f, 0.5f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f},
     };
-    uint32_t numVertices = 3;
+    uint32 numVertices = sizeof(vertices) / sizeof(Vertex);
+
+    uint32 indices[] = {
+        0, 1, 2,
+        1, 2, 3
+    };
+    uint32 numIndices = sizeof(indices) / sizeof(uint32);
+
+    GLuint indexBuffer;
+    glGenBuffers(1, &indexBuffer);
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
+    glBufferData(GL_ELEMENT_ARRAY_BUFFER, numIndices * sizeof(indices[0]), indices, GL_STATIC_DRAW);
 
     VertexBuffer vertexBuffer(vertices, numVertices);
     vertexBuffer.unbind();
@@ -64,7 +77,8 @@ int main() {
 
         // FRAME GENERATION
         vertexBuffer.bind();
-        glDrawArrays(GL_TRIANGLES, 0, numVertices);
+        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
+        glDrawElements(GL_TRIANGLES, numIndices, GL_UNSIGNED_INT, 0);
         vertexBuffer.unbind();
 
         SDL_GL_SwapWindow(window);
@@ -79,7 +93,7 @@ int main() {
         const uint64 counterElapsed = endCounter - lastCounter;
         delta = (static_cast<float32>(counterElapsed) / static_cast<float32>(perfCounterFrequency));
         const auto FPS = static_cast<uint32>(static_cast<float32>(perfCounterFrequency) / static_cast<float32>(counterElapsed));
-        std::cout << "FPS: " << FPS << std::endl;
+        //std::cout << "FPS: " << FPS << std::endl;
         lastCounter = endCounter;
     }