From 5b43e3d5bea00c6703af844151db30066dabccf3 Mon Sep 17 00:00:00 2001
From: Gregory Wells <me@gregorywells.dev>
Date: Tue, 12 Aug 2025 23:51:04 -0400
Subject: [PATCH] OpenGL buffers

---
 .../apis/opengl/loader/opengl_device_loader.c | 12 ++++---
 .../apis/opengl/src/buffer/opengl_buffer.c    | 33 +++++++++++++++++++
 .../apis/opengl/src/buffer/opengl_buffer.h    | 15 +++++++++
 3 files changed, 55 insertions(+), 5 deletions(-)
 create mode 100644 projects/apis/opengl/src/buffer/opengl_buffer.c
 create mode 100644 projects/apis/opengl/src/buffer/opengl_buffer.h

diff --git a/projects/apis/opengl/loader/opengl_device_loader.c b/projects/apis/opengl/loader/opengl_device_loader.c
index 2040df5..b05b767 100644
--- a/projects/apis/opengl/loader/opengl_device_loader.c
+++ b/projects/apis/opengl/loader/opengl_device_loader.c
@@ -5,6 +5,7 @@
 #include "renderpass/opengl_render_pass_descriptor.h"
 #include "uniforms/pool/opengl_uniform_pool.h"
 #include "commands/pool/opengl_command_pool.h"
+#include "buffer/opengl_buffer.h"
 
 gnDeviceFunctions loadOpenGLDeviceFunctions() {
     return (gnDeviceFunctions){
@@ -27,11 +28,12 @@ gnDeviceFunctions loadOpenGLDeviceFunctions() {
         ._gnCreateCommandPool = openglCreateCommandPool,
         ._gnDestroyCommandPool = openglDestroyCommandPool,
 
-        ._gnCreateBuffer = NULL,
-        ._gnBufferData = NULL,
-        ._gnBufferSubData = NULL,
-        ._gnMapBuffer = NULL,
-        ._gnDestroyBuffer = NULL,
+        ._gnCreateBuffer = openglCreateBuffer,
+        ._gnBufferData = openglBufferData,
+        ._gnBufferSubData = openglBufferSubData,
+        ._gnMapBuffer = openglMapBuffer,
+        ._gnUnmapBuffer = openglUnmapBuffer,
+        ._gnDestroyBuffer = openglDestroyBuffer,
 
         ._gnCreateUniformPool = openglCreateUniformPool,
         ._gnUniformPoolAllocateUniforms = openglAllocateUniforms,
diff --git a/projects/apis/opengl/src/buffer/opengl_buffer.c b/projects/apis/opengl/src/buffer/opengl_buffer.c
new file mode 100644
index 0000000..0f99108
--- /dev/null
+++ b/projects/apis/opengl/src/buffer/opengl_buffer.c
@@ -0,0 +1,33 @@
+#include "opengl_buffer.h"
+
+GLenum gnBufferTypeToGLEnum(gnBufferType type) {
+    switch (type) {
+    case GN_VERTEX_BUFFER: return GL_ARRAY_BUFFER;
+    case GN_INDEX_BUFFER: return GL_ELEMENT_ARRAY_BUFFER;
+    case GN_UNIFORM_BUFFER: return GL_UNIFORM_BUFFER;
+    case GN_STORAGE_BUFFER: return GL_SHADER_STORAGE_BUFFER;
+    }
+}
+
+gnReturnCode openglCreateBuffer(gnBufferHandle buffer, gnDevice device, gnBufferInfo info) {
+    buffer->buffer = malloc(sizeof(gnPlatformBuffer));
+    glCreateBuffers(1, &buffer->buffer->id);
+    buffer->buffer->type = gnBufferTypeToGLEnum(info.type);
+    buffer->buffer->usage = (info.usage == GN_DYNAMIC_DRAW) ? GL_DYNAMIC_DRAW : GL_STATIC_DRAW;
+    return GN_SUCCESS;
+}
+void openglBufferData(gnBufferHandle buffer, size_t dataSize, void* data) {
+    glNamedBufferData(buffer->buffer->id, dataSize, data, buffer->buffer->usage);
+}
+void openglBufferSubData(gnBufferHandle buffer, size_t offset, size_t dataSize, gnBufferMemory data) {
+    glNamedBufferSubData(buffer->buffer->id, offset, dataSize, data);
+}
+void* openglMapBuffer(gnBufferHandle buffer) {
+    return glMapNamedBuffer(buffer->buffer->id, GL_READ_WRITE);
+}
+void openglUnmapBuffer(gnBufferHandle buffer) {
+    glUnmapNamedBuffer(buffer->buffer->id);
+}
+void openglDestroyBuffer(gnBufferHandle buffer) {
+    glDeleteBuffers(1, &buffer->buffer->id);
+}
diff --git a/projects/apis/opengl/src/buffer/opengl_buffer.h b/projects/apis/opengl/src/buffer/opengl_buffer.h
new file mode 100644
index 0000000..878864f
--- /dev/null
+++ b/projects/apis/opengl/src/buffer/opengl_buffer.h
@@ -0,0 +1,15 @@
+#pragma once
+#include "core/src/buffers/gryphn_buffer.h"
+#include "glad/glad.h"
+
+typedef struct gnPlatformBuffer_t {
+    GLuint id;
+    GLenum type, usage;
+} gnPlatformBuffer;
+
+gnReturnCode openglCreateBuffer(gnBufferHandle buffer, gnDevice device, gnBufferInfo info);
+void openglBufferData(gnBufferHandle buffer, size_t dataSize, void* data);
+void openglBufferSubData(gnBufferHandle buffer, size_t offset, size_t dataSize, gnBufferMemory data);
+void* openglMapBuffer(gnBufferHandle buffer);
+void openglUnmapBuffer(gnBufferHandle buffer);
+void openglDestroyBuffer(gnBufferHandle buffer);