/*
 * Copyright (C) 2009 Maciej Cencora <m.cencora@gmail.com>
 *
 * All Rights Reserved.
 *
 * 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 (including the
 * next paragraph) 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 COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS 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.
 *
 */

/**
 * \file
 *
 * Fragment program compiler. Perform transformations on the intermediate
 * representation until the program is in a form where we can translate
 * it more or less directly into machine-readable form.
 *
 * \author Ben Skeggs <darktama@iinet.net.au>
 * \author Jerome Glisse <j.glisse@gmail.com>
 */

#include "r300_fragprog_common.h"

#include "shader/program.h"
#include "shader/prog_parameter.h"
#include "shader/prog_print.h"

#include "r300_state.h"
#include "r300_fragprog.h"
#include "r300_fragprog_swizzle.h"
#include "r500_fragprog.h"

#include "radeon_program.h"
#include "radeon_program_alu.h"

static void nqssadce_init(struct nqssadce_state* s)
{
	s->Outputs[FRAG_RESULT_COLOR].Sourced = WRITEMASK_XYZW;
	s->Outputs[FRAG_RESULT_DEPTH].Sourced = WRITEMASK_W;
}

/**
 * Transform the program to support fragment.position.
 *
 * Introduce a small fragment at the start of the program that will be
 * the only code that directly reads the FRAG_ATTRIB_WPOS input.
 * All other code pieces that reference that input will be rewritten
 * to read from a newly allocated temporary.
 *
 */
static void insert_WPOS_trailer(struct r300_fragment_program_compiler *compiler)
{
	GLuint InputsRead = compiler->fp->Base->InputsRead;

	if (!(InputsRead & FRAG_BIT_WPOS)) {
		compiler->fp->wpos_attr = FRAG_ATTRIB_MAX;
		return;
	}

	static gl_state_index tokens[STATE_LENGTH] = {
		STATE_INTERNAL, STATE_R300_WINDOW_DIMENSION, 0, 0, 0
	};
	struct prog_instruction *fpi;
	GLuint window_index;
	int i = 0;

	for (i = FRAG_ATTRIB_TEX0; i <= FRAG_ATTRIB_TEX7; ++i)
	{
		if (!(InputsRead & (1 << i))) {
			InputsRead &= ~(1 << FRAG_ATTRIB_WPOS);
			InputsRead |= 1 << i;
			compiler->fp->Base->InputsRead = InputsRead;
			compiler->fp->wpos_attr = i;
			break;
		}
	}

	GLuint tempregi = _mesa_find_free_register(compiler->program, PROGRAM_TEMPORARY);

	_mesa_insert_instructions(compiler->program, 0, 3);
	fpi = compiler->program->Instructions;
	i = 0;

	/* perspective divide */
	fpi[i].Opcode = OPCODE_RCP;

	fpi[i].DstReg.File = PROGRAM_TEMPORARY;
	fpi[i].DstReg.Index = tempregi;
	fpi[i].DstReg.WriteMask = WRITEMASK_W;
	fpi[i].DstReg.CondMask = COND_TR;

	fpi[i].SrcReg[0].File = PROGRAM_INPUT;
	fpi[i].SrcReg[0].Index = compiler->fp->wpos_attr;
	fpi[i].SrcReg[0].Swizzle = SWIZZLE_WWWW;
	i++;

	fpi[i].Opcode = OPCODE_MUL;

	fpi[i].DstReg.File = PROGRAM_TEMPORARY;
	fpi[i].DstReg.Index = tempregi;
	fpi[i].DstReg.WriteMask = WRITEMASK_XYZ;
	fpi[i].DstReg.CondMask = COND_TR;

	fpi[i].SrcReg[0].File = PROGRAM_INPUT;
	fpi[i].SrcReg[0].Index = compiler->fp->wpos_attr;
	fpi[i].SrcReg[0].Swizzle = SWIZZLE_XYZW;

	fpi[i].SrcReg[1].File = PROGRAM_TEMPORARY;
	fpi[i].SrcReg[1].Index = tempregi;
	fpi[i].SrcReg[1].Swizzle = SWIZZLE_WWWW;
	i++;

	/* viewport transformation */
	window_index = _mesa_add_state_reference(compiler->program->Parameters, tokens);

	fpi[i].Opcode = OPCODE_MAD;

	fpi[i].DstReg.File = PROGRAM_TEMPORARY;
	fpi[i].DstReg.Index = tempregi;
	fpi[i].DstReg.WriteMask = WRITEMASK_XYZ;
	fpi[i].DstReg.CondMask = COND_TR;

	fpi[i].SrcReg[0].File = PROGRAM_TEMPORARY;
	fpi[i].SrcReg[0].Index = tempregi;
	fpi[i].SrcReg[0].Swizzle = MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_ZERO);

	fpi[i].SrcReg[1].File = PROGRAM_STATE_VAR;
	fpi[i].SrcReg[1].Index = window_index;
	fpi[i].SrcReg[1].Swizzle = MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_ZERO);

	fpi[i].SrcReg[2].File = PROGRAM_STATE_VAR;
	fpi[i].SrcReg[2].Index = window_index;
	fpi[i].SrcReg[2].Swizzle = MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_ZERO);
	i++;

	for (; i < compiler->program->NumInstructions; ++i) {
		int reg;
		for (reg = 0; reg < 3; reg++) {
			if (fpi[i].SrcReg[reg].File == PROGRAM_INPUT &&
			    fpi[i].SrcReg[reg].Index == FRAG_ATTRIB_WPOS) {
				fpi[i].SrcReg[reg].File = PROGRAM_TEMPORARY;
				fpi[i].SrcReg[reg].Index = tempregi;
			}
		}
	}
}


/**
 * Rewrite fragment.fogcoord to use a texture coordinate slot.
 * Note that fogcoord is forced into an X001 pattern, and this enforcement
 * is done here.
 *
 * See also the counterpart rewriting for vertex programs.
 */
static void rewriteFog(struct r300_fragment_program_compiler *compiler)
{
	struct r300_fragment_program *fp = compiler->fp;
	GLuint InputsRead;
	int i;

	InputsRead = fp->Base->InputsRead;

	if (!(InputsRead & FRAG_BIT_FOGC)) {
		fp->fog_attr = FRAG_ATTRIB_MAX;
		return;
	}

	for (i = FRAG_ATTRIB_TEX0; i <= FRAG_ATTRIB_TEX7; ++i)
	{
		if (!(InputsRead & (1 << i))) {
			InputsRead &= ~(1 << FRAG_ATTRIB_FOGC);
			InputsRead |= 1 << i;
			fp->Base->InputsRead = InputsRead;
			fp->fog_attr = i;
			break;
		}
	}

	{
		struct prog_instruction *inst;

		inst = compiler->program->Instructions;
		while (inst->Opcode != OPCODE_END) {
			const int src_regs = _mesa_num_inst_src_regs(inst->Opcode);
			for (i = 0; i < src_regs; ++i) {
				if (inst->SrcReg[i].File == PROGRAM_INPUT && inst->SrcReg[i].Index == FRAG_ATTRIB_FOGC) {
					inst->SrcReg[i].Index = fp->fog_attr;
					inst->SrcReg[i].Swizzle = combine_swizzles(
						MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_ZERO, SWIZZLE_ZERO, SWIZZLE_ONE),
						inst->SrcReg[i].Swizzle);
				}
			}
			++inst;
		}
	}
}

static GLuint build_dtm(GLuint depthmode)
{
	switch(depthmode) {
	default:
	case GL_LUMINANCE: return 0;
	case GL_INTENSITY: return 1;
	case GL_ALPHA: return 2;
	}
}

static GLuint build_func(GLuint comparefunc)
{
	return comparefunc - GL_NEVER;
}

/**
 * Collect all external state that is relevant for compiling the given
 * fragment program.
 */
static void build_state(
	r300ContextPtr r300,
	struct gl_fragment_program *fp,
	struct r300_fragment_program_external_state *state)
{
	int unit;

	_mesa_bzero(state, sizeof(*state));

	for(unit = 0; unit < 16; ++unit) {
		if (fp->Base.ShadowSamplers & (1 << unit)) {
			struct gl_texture_object* tex = r300->radeon.glCtx->Texture.Unit[unit]._Current;

			state->unit[unit].depth_texture_mode = build_dtm(tex->DepthMode);
			state->unit[unit].texture_compare_func = build_func(tex->CompareFunc);
		}
	}
}

static void rewrite_depth_out(struct gl_program *prog)
{
	struct prog_instruction *inst;

	for (inst = prog->Instructions; inst->Opcode != OPCODE_END; ++inst) {
		if (inst->DstReg.File != PROGRAM_OUTPUT || inst->DstReg.Index != FRAG_RESULT_DEPTH)
			continue;

		if (inst->DstReg.WriteMask & WRITEMASK_Z) {
			inst->DstReg.WriteMask = WRITEMASK_W;
		} else {
			inst->DstReg.WriteMask = 0;
			continue;
		}

		switch (inst->Opcode) {
			case OPCODE_FRC:
			case OPCODE_MOV:
				inst->SrcReg[0] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[0]);
				break;
			case OPCODE_ADD:
			case OPCODE_MAX:
			case OPCODE_MIN:
			case OPCODE_MUL:
				inst->SrcReg[0] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[0]);
				inst->SrcReg[1] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[1]);
				break;
			case OPCODE_CMP:
			case OPCODE_MAD:
				inst->SrcReg[0] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[0]);
				inst->SrcReg[1] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[1]);
				inst->SrcReg[2] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[2]);
				break;
			default:
				// Scalar instructions needn't be reswizzled
				break;
		}
	}
}

void r300TranslateFragmentShader(GLcontext *ctx, struct r300_fragment_program *fp)
{
	r300ContextPtr r300 = R300_CONTEXT(ctx);
	struct r300_fragment_program_compiler compiler;

	compiler.r300 = r300;
	compiler.fp = fp;
	compiler.code = &fp->code;
	compiler.program = fp->Base;

	if (RADEON_DEBUG & DEBUG_PIXEL) {
		fflush(stdout);
		_mesa_printf("Fragment Program: Initial program:\n");
		_mesa_print_program(compiler.program);
		fflush(stdout);
	}

	insert_WPOS_trailer(&compiler);

	rewriteFog(&compiler);

	rewrite_depth_out(compiler.program);

	if (r300->radeon.radeonScreen->chip_family >= CHIP_FAMILY_RV515) {
		struct radeon_program_transformation transformations[] = {
			{ &r500_transform_TEX, &compiler },
			{ &radeonTransformALU, 0 },
			{ &radeonTransformDeriv, 0 },
			{ &radeonTransformTrigScale, 0 }
		};
		radeonLocalTransform(ctx, compiler.program, 4, transformations);
	} else {
		struct radeon_program_transformation transformations[] = {
			{ &r300_transform_TEX, &compiler },
			{ &radeonTransformALU, 0 },
			{ &radeonTransformTrigSimple, 0 }
		};
		radeonLocalTransform(ctx, compiler.program, 3, transformations);
	}

	if (RADEON_DEBUG & DEBUG_PIXEL) {
		_mesa_printf("Fragment Program: After native rewrite:\n");
		_mesa_print_program(compiler.program);
		fflush(stdout);
	}

	if (r300->radeon.radeonScreen->chip_family >= CHIP_FAMILY_RV515) {
		struct radeon_nqssadce_descr nqssadce = {
			.Init = &nqssadce_init,
			.IsNativeSwizzle = &r500FPIsNativeSwizzle,
			.BuildSwizzle = &r500FPBuildSwizzle
		};
		radeonNqssaDce(ctx, compiler.program, &nqssadce);
	} else {
		struct radeon_nqssadce_descr nqssadce = {
			.Init = &nqssadce_init,
			.IsNativeSwizzle = &r300FPIsNativeSwizzle,
			.BuildSwizzle = &r300FPBuildSwizzle
		};
		radeonNqssaDce(ctx, compiler.program, &nqssadce);
	}

	if (RADEON_DEBUG & DEBUG_PIXEL) {
		_mesa_printf("Compiler: after NqSSA-DCE:\n");
		_mesa_print_program(compiler.program);
		fflush(stdout);
	}

	if (!r300->vtbl.BuildFragmentProgramHwCode(&compiler))
		fp->error = GL_TRUE;

	fp->translated = GL_TRUE;

	if (fp->error || (RADEON_DEBUG & DEBUG_PIXEL))
		r300->vtbl.FragmentProgramDump(&fp->code);
}

struct r300_fragment_program *r300SelectFragmentShader(GLcontext *ctx)
{
	r300ContextPtr r300 = R300_CONTEXT(ctx);
	struct r300_fragment_program_cont *fp_list;
	struct r300_fragment_program *fp;
	struct r300_fragment_program_external_state state;

	fp_list = (struct r300_fragment_program_cont *)ctx->FragmentProgram._Current;
	build_state(r300, ctx->FragmentProgram._Current, &state);

	fp = fp_list->progs;
	while (fp) {
		if (_mesa_memcmp(&fp->state, &state, sizeof(state)) == 0) {
			return r300->selected_fp = fp;
		}
		fp = fp->next;
	}

	fp = _mesa_calloc(sizeof(struct r300_fragment_program));

	fp->state = state;
	fp->translated = GL_FALSE;
	fp->Base = _mesa_clone_program(ctx, &ctx->FragmentProgram._Current->Base);

	fp->next = fp_list->progs;
	fp_list->progs = fp;

	return r300->selected_fp = fp;
}