#include "rc1.0_general.h"
#include "nvparse_errors.h"
#include "nvparse_externs.h"
#include <stdio.h>

#include <OgreGLPrerequisites.h>

void GeneralCombinersStruct::Validate(int numConsts, ConstColorStruct *pcc)
{
	GLint maxGCs;
	glGetIntegerv(GL_MAX_GENERAL_COMBINERS_NV, &maxGCs);
	if (num > maxGCs) {
		char buffer[256];
		sprintf(buffer, "%d general combiners specified, only %d supported", num, (int)maxGCs);
		errors.set(buffer);
		num = maxGCs;
	}

	if (0 == num) {
		// Setup a "fake" general combiner 0
		general[0].ZeroOut();
		num = 1;
	}

	localConsts = 0;
	int i;
	for (i = 0; i < num; i++)
		localConsts += general[i].numConsts;

	if (localConsts > 0)
		if (NULL == glCombinerStageParameterfvNV)
			errors.set("local constant(s) specified, but not supported -- ignored");
		else
			for (i = 0; i < num; i++)
				general[i].SetUnusedLocalConsts(numConsts, pcc);

	for (i = 0; i < num; i++)
		general[i].Validate(i);


	for (; i < maxGCs; i++)
		general[i].ZeroOut();
}

void GeneralCombinersStruct::Invoke()
{
	glCombinerParameteriNV(GL_NUM_GENERAL_COMBINERS_NV, num);
	int i;
	for (i = 0; i < num; i++)
		general[i].Invoke(i);
	
	if (NULL != glCombinerStageParameterfvNV) {
		if (localConsts > 0)
			glEnable(GL_PER_STAGE_CONSTANTS_NV);
		else
			glDisable(GL_PER_STAGE_CONSTANTS_NV);
	}
		
}

void GeneralCombinerStruct::ZeroOut()
{
		numPortions = 2;
		numConsts = 0;

		portion[0].ZeroOut();
		portion[0].designator = RCP_RGB;
		portion[1].ZeroOut();
		portion[1].designator = RCP_ALPHA;
}


void GeneralCombinerStruct::SetUnusedLocalConsts(int numGlobalConsts, ConstColorStruct *globalCCs)
{
        int i;
	for (i = 0; i < numGlobalConsts; i++) {
		bool constUsed = false;
		int j;
		for (j = 0; j < numConsts; j++)
			constUsed |= (cc[j].reg.bits.name == globalCCs[i].reg.bits.name);
		if (!constUsed)
			cc[numConsts++] = globalCCs[i];
	}
}


void GeneralCombinerStruct::Validate(int stage)
{
	if (2 == numConsts &&
		cc[0].reg.bits.name == cc[1].reg.bits.name)
		errors.set("local constant set twice");

	switch (numPortions)
	{
	case 0:
		portion[0].designator = RCP_RGB;
		// Fallthru
	case 1:
		portion[1].designator = ((RCP_RGB == portion[0].designator) ? RCP_ALPHA : RCP_RGB);
		// Fallthru
	case 2:
		if (portion[0].designator == portion[1].designator)
			errors.set("portion declared twice");
		break;
	}
	int i;
	for (i = 0; i < numPortions; i++)
		portion[i].Validate(stage);

	for (; i < 2; i++)
		portion[i].ZeroOut();

}

void GeneralCombinerStruct::Invoke(int stage)
{
	int i;

	if (NULL != glCombinerStageParameterfvNV)
		for (i = 0; i < numConsts; i++)
			glCombinerStageParameterfvNV(GL_COMBINER0_NV + stage, cc[i].reg.bits.name, &(cc[i].v[0]));

	for (i = 0; i < 2; i++)
		portion[i].Invoke(stage);
}

void GeneralPortionStruct::Validate(int stage)
{
	gf.Validate(stage, designator);
}

void GeneralPortionStruct::Invoke(int stage)
{
	gf.Invoke(stage, designator, bs);
}

void GeneralPortionStruct::ZeroOut()
{
	gf.ZeroOut();
	bs.word = RCP_SCALE_BY_ONE;
}

void GeneralFunctionStruct::ZeroOut()
{
	// Create mapped registers for zero and discard
	MappedRegisterStruct unsignedZero;
	RegisterEnum zero;
	zero.word = RCP_ZERO;
	unsignedZero.Init(zero);

	MappedRegisterStruct unsignedDiscard;
	RegisterEnum discard;
	discard.word = RCP_DISCARD;
	unsignedDiscard.Init(discard);

	numOps = 3;

	op[0].op = RCP_MUL;
	op[0].reg[0] = unsignedDiscard;
	op[0].reg[1] = unsignedZero;
	op[0].reg[2] = unsignedZero;

	op[1].op = RCP_MUL;
	op[1].reg[0] = unsignedDiscard;
	op[1].reg[1] = unsignedZero;
	op[1].reg[2] = unsignedZero;

	op[2].op = RCP_SUM;
	op[2].reg[0] = unsignedDiscard;

}

void GeneralFunctionStruct::Validate(int stage, int portion)
{
        int i;
	for (i = 0; i < numOps; i++)
		op[i].Validate(stage, portion);
	// Check if multiple ops are writing to same register (and it's not DISCARD)
	if (numOps > 1 &&
		op[0].reg[0].reg.bits.name == op[1].reg[0].reg.bits.name &&
		GL_DISCARD_NV != op[0].reg[0].reg.bits.name)
		errors.set("writing to same register twice");
	if (numOps > 2 &&
		(op[0].reg[0].reg.bits.name == op[2].reg[0].reg.bits.name ||
		 op[1].reg[0].reg.bits.name == op[2].reg[0].reg.bits.name) &&
		GL_DISCARD_NV != op[2].reg[0].reg.bits.name)
		errors.set("writing to same register twice");

	// Set unused outputs to discard, unused inputs to zero/unsigned_identity
	if (numOps < 2) {
		// Set C input to zero
		op[1].reg[1].reg.bits.name = GL_ZERO;
		op[1].reg[1].map = GL_UNSIGNED_IDENTITY_NV;
		op[1].reg[1].reg.bits.channel = portion;

		// Set D input to zero
		op[1].reg[2].reg.bits.name = GL_ZERO;
		op[1].reg[2].map = GL_UNSIGNED_IDENTITY_NV;
		op[1].reg[2].reg.bits.channel = portion;

		// Discard CD output
		op[1].op = false;
		op[1].reg[0].reg.bits.name = GL_DISCARD_NV;
	}

	if (numOps < 3) {
		// Discard muxSum output
		op[2].reg[0].reg.bits.name = GL_DISCARD_NV;
		op[2].op = RCP_SUM;
	}
}


void GeneralFunctionStruct::Invoke(int stage, int portion, BiasScaleEnum bs)
{
	GLenum portionEnum = (RCP_RGB == portion) ? GL_RGB : GL_ALPHA;

	glCombinerInputNV(GL_COMBINER0_NV + stage,
		portionEnum,
		GL_VARIABLE_A_NV,
		op[0].reg[1].reg.bits.name,
		op[0].reg[1].map,
		MAP_CHANNEL(op[0].reg[1].reg.bits.channel));

	glCombinerInputNV(GL_COMBINER0_NV + stage,
		portionEnum,
		GL_VARIABLE_B_NV,
		op[0].reg[2].reg.bits.name,
		op[0].reg[2].map,
		MAP_CHANNEL(op[0].reg[2].reg.bits.channel));

	glCombinerInputNV(GL_COMBINER0_NV + stage,
		portionEnum,
		GL_VARIABLE_C_NV,
		op[1].reg[1].reg.bits.name,
		op[1].reg[1].map,
		MAP_CHANNEL(op[1].reg[1].reg.bits.channel));

	glCombinerInputNV(GL_COMBINER0_NV + stage,
		portionEnum,
		GL_VARIABLE_D_NV,
		op[1].reg[2].reg.bits.name,
		op[1].reg[2].map,
		MAP_CHANNEL(op[1].reg[2].reg.bits.channel));

	glCombinerOutputNV(GL_COMBINER0_NV + stage,
		portionEnum,
		op[0].reg[0].reg.bits.name,
		op[1].reg[0].reg.bits.name,
		op[2].reg[0].reg.bits.name,
		bs.bits.scale,
		bs.bits.bias,
		op[0].op,
		op[1].op,
		(op[2].op == RCP_MUX) ? true : false);
}

// This helper function assigns a channel to an undesignated input register
static void ConvertRegister(RegisterEnum& reg, int portion)
{
	if (RCP_NONE == reg.bits.channel) {
		reg.bits.channel = portion;
		if (GL_FOG == reg.bits.name && RCP_ALPHA == portion)
			// Special case where fog alpha is final only, but RGB is not
			reg.bits.finalOnly = true;
	}
}


void OpStruct::Validate(int stage, int portion)
{
	int args = 1;

	if (RCP_DOT == op || RCP_MUL == op)
		args = 3;
	else
		args = 1;

	if (reg[0].reg.bits.readOnly)
		errors.set("writing to a read-only register");

	if (RCP_ALPHA == portion &&
		RCP_DOT == op)
		errors.set("dot used in alpha portion");
	int i;
	for (i = 0; i < args; i++) {
		ConvertRegister(reg[i].reg, portion);
		if (reg[i].reg.bits.finalOnly)
			errors.set("final register used in general combiner");
		if (RCP_RGB == portion &&
			RCP_BLUE == reg[i].reg.bits.channel)
			errors.set("blue register used in rgb portion");
		if (RCP_ALPHA == portion &&
			RCP_RGB == reg[i].reg.bits.channel)
			errors.set("rgb register used in alpha portion");
		if (i > 0 &&
			GL_DISCARD_NV == reg[i].reg.bits.name)
			errors.set("reading from discard");
	}
}