MacGLide/MacGLide/OpenGLide/Framebuffer.cpp

//**************************************************************
//*            OpenGLide - Glide to OpenGL Wrapper
//*             http://openglide.sourceforge.net
//*
//*                  framebuffer emulation
//*
//*         OpenGLide is OpenSource under LGPL license
//*  Mac version and additional features by Jens-Olaf Hemprich
//**************************************************************

#include "Framebuffer.h"
#include "Glide.h"
#include "GlideApplication.h"
#include "GlideSettings.h"
#include "GLRender.h"
#include "GLRenderUpdateState.h"
#include "GLColorAlphaCombineEnvTables.h"

// Displays small dots in tile edges, disables all optimisations
// #define DEBUG_TILE_RENDERING

Framebuffer::Framebuffer()
: m_x_step_start(0)
, m_y_step_start(0)
, m_x_step_start_opaque(0)
, m_y_step_start_opaque(0)
, m_width(0)
, m_height(0)
, m_framebuffer(NULL)
, m_texbuffer(NULL)
, m_origin(GR_ORIGIN_UPPER_LEFT)
, m_glInternalFormat(-1)
, m_glFormat(-1)
, m_glType(-1)
, m_glDepth(1.0f)
, m_format_valid(false)
, m_useRectangleARB(false)
, m_must_clear_buffer(true)
, m_custom_tilesizes(NULL)
{
#ifdef __ALTIVEC__
	for(int i = 0; i < 4; i++)
	{
		(&m_glAlpha.Scalar)[i] = 0x000000ff;
	}
#else
	m_glAlpha.Scalar = 0x000000ff;
#endif
}

Framebuffer::~Framebuffer()
{
}

inline int Framebuffer::getTileCount() const
{
	return m_tilesizesCount + m_customtilesizesCount;
}

bool Framebuffer::initialise_buffers(BufferStruct* framebuffer, BufferStruct* texbuffer, FxU32 width, FxU32 height, const tilesize* tilesizetable)
{
	#ifdef OGL_FRAMEBUFFER
		GlideMsg( "GlideFrameBuffer::initialise_buffers(---, ---, %d, %d, ---)\n", width, height);
	#endif

	m_custom_tilesizes = tilesizetable;
	return initialise_buffers(framebuffer, texbuffer, width, height, 0, 0);
}

bool Framebuffer::initialise_buffers(BufferStruct* framebuffer, BufferStruct* texbuffer, FxU32 width, FxU32 height, FxU32 x_tile, FxU32 y_tile)
{
	#ifdef OGL_FRAMEBUFFER
		GlideMsg( "Framebuffer::initialise_buffers(---, ---, %d, %d, %d, %d)\n", width, height, x_tile, y_tile);
	#endif

	m_framebuffer = framebuffer;
	m_texbuffer = texbuffer;
	m_framebuffer->WriteMode = m_texbuffer->WriteMode = GR_LFBWRITEMODE_UNUSED;
	m_width = width;
	m_height = height;
	// find out largest texture size
	GLint tile_size;
	glGetIntegerv(GL_MAX_TEXTURE_SIZE, &tile_size);
	m_x_step_start_opaque = tile_size;
	m_y_step_start_opaque = tile_size;
	m_x_step_start = min(tile_size, x_tile);
	m_y_step_start = min(tile_size, y_tile);
	m_x_step_start = max(16, m_x_step_start);
	m_y_step_start = max(16, m_y_step_start);
	m_useRectangleARB = InternalConfig.ARB_texture_rectangle &&
	                    InternalConfig.EXT_compiled_vertex_array;
	// If a game has its own tilesize table, use
	// the largest tiles for opaque renderings
	GLint y_step = y_tile == 0 ? m_y_step_start_opaque : m_y_step_start;
	// init default/opaque tilesize table
	int w = 0;
	for(FxU32 y = 0; y < m_height && w < MaxTiles ; y += y_step, w++)
	{
		while (m_height - y < y_step)
		{
			y_step = y_step >> 1;
		}
		m_tilesizes[w].y = y_step;
		GLint x_step = x_tile == 0 ? m_x_step_start_opaque : m_x_step_start;
		int v = 0;
		for(FxU32 x = 0; x < m_width && v < MaxTiles; x += x_step, v++ )
		{
			while (m_width - x < x_step)
			{
				x_step = x_step >> 1;
			}
			m_tilesizes[w].x[v] = x_step;
		}
	}
	// This is always initialised as the immediate mode also uses the precalculated tile coordinates
	buildVertexArrays();
	// The texture priority is set to maximum
	// because of the altivec checksum feature
	const GLfloat priority = 1.0f;
	const int tileCount = getTileCount();
	glGenTextures(tileCount, &m_textureNames[0]);
	glPrioritizeTextures(tileCount, &m_textureNames[0], &priority);
	for(int i = 0; i < tileCount; i++)
	{
		const GLenum textureTarget = m_useRectangleARB ? GL_TEXTURE_RECTANGLE_ARB : GL_TEXTURE_2D;
		glBindTexture(textureTarget, m_textureNames[i]);
		glTexParameteri(textureTarget, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
		glTexParameteri(textureTarget, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
		glTexParameteri(textureTarget, GL_TEXTURE_WRAP_S, GL_CL