- added an abstract index buffer implementation as well.

src/gl/system/gl_framebuffer.cpp

@@ -44,6 +44,7 @@
 #include "gl/shaders/gl_shaderprogram.h"
 #include "gl_debug.h"
 #include "r_videoscale.h"
+#include "glsys_vertexbuffer.h"
 
 EXTERN_CVAR (Bool, vid_vsync)
 
@@ -361,6 +362,16 @@ IShaderProgram *OpenGLFrameBuffer::CreateShaderProgram()
 	return new FShaderProgram; 
 }
 
+IVertexBuffer *OpenGLFrameBuffer::CreateVertexBuffer()
+{ 
+	return new GLVertexBuffer; 
+}
+
+IIndexBuffer *OpenGLFrameBuffer::CreateIndexBuffer()
+{ 
+	return new GLIndexBuffer; 
+}
+
 
 void OpenGLFrameBuffer::TextureFilterChanged()
 {

src/gl/system/gl_framebuffer.h

@@ -43,6 +43,8 @@ public:
 	void BlurScene(float amount) override;
     IUniformBuffer *CreateUniformBuffer(size_t size, bool staticuse = false) override;
 	IShaderProgram *CreateShaderProgram() override;
+	IVertexBuffer *CreateVertexBuffer() override;
+	IIndexBuffer *CreateIndexBuffer() override;
 
 	// Retrieves a buffer containing image data for a screenshot.
 	// Hint: Pitch can be negative for upside-down images, in which case buffer

src/gl/system/glsys_vertexbuffer.cpp

@@ -30,7 +30,7 @@
 
 //==========================================================================
 //
-// Create / destroy the VBO
+// Vertex buffer implementation
 //
 //==========================================================================
 
@@ -47,6 +47,7 @@ GLVertexBuffer::~GLVertexBuffer()
 		glUnmapBuffer(GL_ARRAY_BUFFER);
 		glBindBuffer(GL_ARRAY_BUFFER, 0);
 		glDeleteBuffers(1, &vbo_id);
+		gl_RenderState.ResetVertexBuffer();
 	}
 }
 
@@ -141,3 +142,41 @@ void GLVertexBuffer::Bind(size_t *offsets)
 		i++;
 	}
 }
+
+//==========================================================================
+//
+// Index buffer implementation
+//
+//==========================================================================
+
+GLIndexBuffer::GLIndexBuffer()
+{
+	glGenBuffers(1, &ibo_id);
+}
+
+GLIndexBuffer::~GLIndexBuffer()
+{
+	if (ibo_id != 0)
+	{
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo_id);
+		glUnmapBuffer(GL_ELEMENT_ARRAY_BUFFER);
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+		glDeleteBuffers(1, &ibo_id);
+	}
+}
+
+void GLIndexBuffer::SetData(size_t size, void *data, bool staticdata)
+{
+	if (data != nullptr)
+	{
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo_id);
+		glBufferData(GL_ELEMENT_ARRAY_BUFFER, size, data, staticdata? GL_STATIC_DRAW : GL_STREAM_DRAW);
+	}
+	buffersize = size;
+	gl_RenderState.ResetVertexBuffer();	// This is needed because glBindBuffer overwrites the setting stored in the render state.
+}
+
+void GLIndexBuffer::Bind()
+{
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo_id);
+}

src/gl/system/glsys_vertexbuffer.h

@@ -2,7 +2,7 @@
 
 #include "hwrenderer/data/vertexbuffer.h"
 
-class GLVertexBuffer : IVertexBuffer
+class GLVertexBuffer : public IVertexBuffer
 {
 	// If this could use the modern (since GL 4.3) binding system, things would be simpler... :(
 	struct GLVertexBufferAttribute
@@ -22,10 +22,21 @@ class GLVertexBuffer : IVertexBuffer
 public:
 	GLVertexBuffer();
 	~GLVertexBuffer();
-	void SetData(size_t size, void *data, bool staticdata) = 0;
+	void SetData(size_t size, void *data, bool staticdata) override;
 	void SetFormat(int numBindingPoints, int numAttributes, size_t stride, FVertexBufferAttribute *attrs) override;
 	void Bind(size_t *offsets);
 	void Map() override;
 	void Unmap() override;
 };
 
+class GLIndexBuffer : public IIndexBuffer
+{
+	unsigned int ibo_id = 0;
+
+public:
+	GLIndexBuffer();
+	~GLIndexBuffer();
+	void SetData(size_t size, void *data, bool staticdata) override;
+	void Bind();
+};
+

src/hwrenderer/data/vertexbuffer.h

@@ -48,3 +48,16 @@ public:
 	void *Memory() { assert(map); return map; }
 };
 
+
+class IIndexBuffer
+{
+protected:
+	// Element size is fixed to 4, thanks to OpenGL requiring this info to be coded into the glDrawElements call.
+	// This mostly prohibits a more flexible buffer setup but GZDoom doesn't use any other format anyway.
+	// Ob Vulkam, element size is a buffer property and of no concern to the drawing functions (as it should be.)
+	size_t buffersize = 0;
+public:
+	virtual ~IIndexBuffer() {}
+	virtual void SetData(size_t size, void *data, bool staticdata = true) = 0;
+};
+

src/v_video.h

@@ -50,6 +50,8 @@ class IShaderProgram;
 class FTexture;
 struct FPortalSceneState;
 class FSkyDomeCreator;
+class IIndexBuffer;
+class IVertexBuffer;
 
 enum EHWCaps
 {
@@ -450,6 +452,8 @@ public:
     // Interface to hardware rendering resources
     virtual IUniformBuffer *CreateUniformBuffer(size_t size, bool staticuse = false) { return nullptr; }
 	virtual IShaderProgram *CreateShaderProgram() { return nullptr; }
+	virtual IVertexBuffer *CreateVertexBuffer() { return nullptr; }
+	virtual IIndexBuffer *CreateIndexBuffer() { return nullptr; }
 	bool BuffersArePersistent() { return !!(hwcaps & RFL_BUFFER_STORAGE); }
 
 	// Begin/End 2D drawing operations.