Add ConstantBuffer

engine/renderers/ConstantBuffer.h

@@ -0,0 +1,142 @@
+/*
+Copyright (c) 2013 Daniele Bartolini, Michele Rossi
+Copyright (c) 2012 Daniele Bartolini, Simone Boscaratto
+
+Permission is hereby granted, free of charge, to any person
+obtaining a copy of this software and associated documentation
+files (the "Software"), to deal in the Software without
+restriction, including without limitation the rights to use,
+copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#pragma once
+
+#include "Assert.h"
+
+namespace crown
+{
+
+#define MAX_CONSTANT_BUFFER_SIZE 1024 * 1024
+
+enum UniformType
+{
+	UNIFORM_INTEGER_1,
+	UNIFORM_INTEGER_2,
+	UNIFORM_INTEGER_3,
+	UNIFORM_INTEGER_4,
+	UNIFORM_FLOAT_1,
+	UNIFORM_FLOAT_2,
+	UNIFORM_FLOAT_3,
+	UNIFORM_FLOAT_4,
+	UNIFORM_FLOAT_3_X_3,
+	UNIFORM_FLOAT_4_X_4,
+	UNIFORM_END
+};
+
+const size_t UNIFORM_SIZE_TABLE[UNIFORM_END] =
+{
+	sizeof(int32_t) * 1,
+	sizeof(int32_t) * 2,
+	sizeof(int32_t) * 3,
+	sizeof(int32_t) * 4,
+	sizeof(float) * 1,
+	sizeof(float) * 2,
+	sizeof(float) * 3,
+	sizeof(float) * 4,
+	sizeof(float) * 9,
+	sizeof(float) * 16
+};
+
+typedef Id UniformId;
+
+class ConstantBuffer
+{
+public:
+
+	ConstantBuffer()
+		: m_size(0)
+	{
+		commit();
+	}
+
+	void clear()
+	{
+		m_size = 0;
+	}
+
+	void write(uint32_t data)
+	{
+		write(&data, sizeof(uint32_t));
+	}
+
+	uint32_t read()
+	{
+		uint32_t data;
+		read(&data, sizeof(uint32_t));
+		return data;
+	}
+
+	const void* read(size_t size)
+	{
+		CE_ASSERT(m_size + size < MAX_CONSTANT_BUFFER_SIZE, "Constant buffer overflow");
+
+		const void* data = (void*) &m_buffer[m_size];
+		m_size += size;
+
+		return data;
+	}
+
+	void write(const void* data, size_t size)
+	{
+		CE_ASSERT(m_size + size < MAX_CONSTANT_BUFFER_SIZE, "Constant buffer overflow");
+
+		memcpy(&m_buffer[m_size], data, size);
+		m_size += size;
+	}
+
+	void read(void* data, size_t size)
+	{
+		CE_ASSERT(m_size + size < MAX_CONSTANT_BUFFER_SIZE, "Constant buffer overflow");
+
+		memcpy(data, &m_buffer[m_size], size);
+		m_size += size;		
+	}
+
+	void write_constant(UniformId id, UniformType type, void* data, uint8_t num)
+	{
+		size_t size = UNIFORM_SIZE_TABLE[type] * num;
+
+		write(type);
+		write(&id, sizeof(UniformId));
+		write(&size, sizeof(size_t));
+		write(data, size);
+	}
+
+	void commit()
+	{
+		write(UNIFORM_END);
+		m_size = 0;
+	}
+
+private:
+
+	size_t m_size;
+	char m_buffer[MAX_CONSTANT_BUFFER_SIZE];
+};
+
+} // namespace crown