/*
 * Copyright 2012, Haiku, Inc. All Rights Reserved.
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *		Artur Wyszynski, harakash@gmail.com
 *		Alexander von Gluck IV, kallisti5@unixzen.com
 */


#include "GalliumContext.h"

#include <stdio.h>

#include "GLView.h"

#include "bitmap_wrapper.h"

#include "glapi/glapi.h"
#include "pipe/p_format.h"
//#include "state_tracker/st_cb_fbo.h"
//#include "state_tracker/st_cb_flush.h"
#include "state_tracker/st_context.h"
#include "state_tracker/st_gl_api.h"
#include "state_tracker/sw_winsys.h"
#include "sw/hgl/hgl_sw_winsys.h"
#include "util/u_atomic.h"
#include "util/u_memory.h"

#include "target-helpers/inline_sw_helper.h"
#include "target-helpers/inline_debug_helper.h"


#ifdef DEBUG
#	define TRACE(x...) printf("GalliumContext: " x)
#	define CALLED() TRACE("CALLED: %s\n", __PRETTY_FUNCTION__)
#else
#	define TRACE(x...)
#	define CALLED()
#endif
#define ERROR(x...) printf("GalliumContext: " x)


GalliumContext::GalliumContext(ulong options)
	:
	fOptions(options),
	fScreen(NULL),
	fCurrentContext(0)
{
	CALLED();

	// Make all contexts a known value
	for (context_id i = 0; i < CONTEXT_MAX; i++)
		fContext[i] = NULL;

	CreateScreen();

	(void) mtx_init(&fMutex, mtx_plain);
}


GalliumContext::~GalliumContext()
{
	CALLED();

	// Destroy our contexts
	Lock();
	for (context_id i = 0; i < CONTEXT_MAX; i++)
		DestroyContext(i);
	Unlock();

	mtx_destroy(&fMutex);

	// TODO: Destroy fScreen
}


status_t
GalliumContext::CreateScreen()
{
	CALLED();

	// Allocate winsys and attach callback hooks
	struct sw_winsys* winsys = hgl_create_sw_winsys();

	if (!winsys) {
		ERROR("%s: Couldn't allocate sw_winsys!\n", __func__);
		return B_ERROR;
	}

	fScreen = sw_screen_create(winsys);

	if (fScreen == NULL) {
		ERROR("%s: Couldn't create screen!\n", __FUNCTION__);
		FREE(winsys);
		return B_ERROR;
	}

	debug_screen_wrap(fScreen);

	const char* driverName = fScreen->get_name(fScreen);
	ERROR("%s: Using %s driver.\n", __func__, driverName);

	return B_OK;
}


context_id
GalliumContext::CreateContext(Bitmap *bitmap)
{
	CALLED();

	struct hgl_context* context = CALLOC_STRUCT(hgl_context);

	if (!context) {
		ERROR("%s: Couldn't create pipe context!\n", __FUNCTION__);
		return 0;
	}

	// Set up the initial things our context needs
	context->bitmap = bitmap;
	context->colorSpace = get_bitmap_color_space(bitmap);
	context->screen = fScreen;
	context->draw = NULL;
	context->read = NULL;
	context->st = NULL;

	// Create st_gl_api
	context->api = hgl_create_st_api();
	if (!context->api) {
		ERROR("%s: Couldn't obtain Mesa state tracker API!\n", __func__);
		return -1;
	}

	// Create state_tracker manager
	context->manager = hgl_create_st_manager(context);

	// Create state tracker visual
	context->stVisual = hgl_create_st_visual(fOptions);

	// Create state tracker framebuffers
	context->draw = hgl_create_st_framebuffer(context);
	context->read = hgl_create_st_framebuffer(context);

	if (!context->draw || !context->read) {
		ERROR("%s: Problem allocating framebuffer!\n", __func__);
		FREE(context->stVisual);
		return -1;
	}

	// Build state tracker attributes
	struct st_context_attribs attribs;
	memset(&attribs, 0, sizeof(attribs));
	attribs.options.force_glsl_extensions_warn = false;
	attribs.profile = ST_PROFILE_DEFAULT;
	attribs.visual = *context->stVisual;
	attribs.major = 1;
	attribs.minor = 0;
	//attribs.flags |= ST_CONTEXT_FLAG_DEBUG;

	// Create context using state tracker api call
	enum st_context_error result;
	context->st = context->api->create_context(context->api, context->manager,
		&attribs, &result, context->st);

	if (!context->st) {
		ERROR("%s: Couldn't create mesa state tracker context!\n",
			__func__);
		switch (result) {
			case ST_CONTEXT_SUCCESS:
				ERROR("%s: State tracker error: SUCCESS?\n", __func__);
				break;
			case ST_CONTEXT_ERROR_NO_MEMORY:
				ERROR("%s: State tracker error: NO_MEMORY\n", __func__);
				break;
			case ST_CONTEXT_ERROR_BAD_API:
				ERROR("%s: State tracker error: BAD_API\n", __func__);
				break;
			case ST_CONTEXT_ERROR_BAD_VERSION:
				ERROR("%s: State tracker error: BAD_VERSION\n", __func__);
				break;
			case ST_CONTEXT_ERROR_BAD_FLAG:
				ERROR("%s: State tracker error: BAD_FLAG\n", __func__);
				break;
			case ST_CONTEXT_ERROR_UNKNOWN_ATTRIBUTE:
				ERROR("%s: State tracker error: BAD_ATTRIBUTE\n", __func__);
				break;
			case ST_CONTEXT_ERROR_UNKNOWN_FLAG:
				ERROR("%s: State tracker error: UNKNOWN_FLAG\n", __func__);
				break;
		}

		hgl_destroy_st_visual(context->stVisual);
		FREE(context);
		return -1;
	}

	assert(!context->st->st_manager_private);
	context->st->st_manager_private = (void*)context;

	struct st_context *stContext = (struct st_context*)context->st;
	
	// Init Gallium3D Post Processing
	// TODO: no pp filters are enabled yet through postProcessEnable
	context->postProcess = pp_init(stContext->pipe, context->postProcessEnable,
		stContext->cso_context);

	context_id contextNext = -1;
	Lock();
	for (context_id i = 0; i < CONTEXT_MAX; i++) {
		if (fContext[i] == NULL) {
			fContext[i] = context;
			contextNext = i;
			break;
		}
	}
	Unlock();

	if (contextNext < 0) {
		ERROR("%s: The next context is invalid... something went wrong!\n",
			__func__);
		//st_destroy_context(context->st);
		FREE(context->stVisual);
		FREE(context);
		return -1;
	}

	TRACE("%s: context #%" B_PRIu64 " is the next available context\n",
		__func__, contextNext);

	return contextNext;
}


void
GalliumContext::DestroyContext(context_id contextID)
{
	// fMutex should be locked *before* calling DestoryContext

	// See if context is used
	if (!fContext[contextID])
		return;

	if (fContext[contextID]->st) {
		fContext[contextID]->st->flush(fContext[contextID]->st, 0, NULL);
		fContext[contextID]->st->destroy(fContext[contextID]->st);
	}

	if (fContext[contextID]->postProcess)
		pp_free(fContext[contextID]->postProcess);

	// Delete state tracker framebuffer objects
	if (fContext[contextID]->read)
		delete fContext[contextID]->read;
	if (fContext[contextID]->draw)
		delete fContext[contextID]->draw;

	if (fContext[contextID]->stVisual)
		hgl_destroy_st_visual(fContext[contextID]->stVisual);

	if (fContext[contextID]->manager)
		hgl_destroy_st_manager(fContext[contextID]->manager);

	FREE(fContext[contextID]);
}


status_t
GalliumContext::SetCurrentContext(Bitmap *bitmap, context_id contextID)
{
	CALLED();

	if (contextID < 0 || contextID > CONTEXT_MAX) {
		ERROR("%s: Invalid context ID range!\n", __func__);
		return B_ERROR;
	}

	Lock();
	context_id oldContextID = fCurrentContext;
	struct hgl_context* context = fContext[contextID];
	Unlock();

	if (!context) {
		ERROR("%s: Invalid context provided (#%" B_PRIu64 ")!\n",
			__func__, contextID);
		return B_ERROR;
	}

	if (!bitmap) {
		context->api->make_current(context->api, NULL, NULL, NULL);
		return B_OK;
	}

	// Everything seems valid, lets set the new context.
	fCurrentContext = contextID;

	if (oldContextID > 0 && oldContextID != contextID) {
		fContext[oldContextID]->st->flush(fContext[oldContextID]->st,
			ST_FLUSH_FRONT, NULL);
	}

	// We need to lock and unlock framebuffers before accessing them
	context->api->make_current(context->api, context->st, context->draw->stfbi,
		context->read->stfbi);

	//if (context->textures[ST_ATTACHMENT_BACK_LEFT]
	//	&& context->textures[ST_ATTACHMENT_DEPTH_STENCIL]
	//	&& context->postProcess) {
	//	TRACE("Postprocessing textures...\n");
	//	pp_init_fbos(context->postProcess,
	//		context->textures[ST_ATTACHMENT_BACK_LEFT]->width0,
	//		context->textures[ST_ATTACHMENT_BACK_LEFT]->height0);
	//}

	context->bitmap = bitmap;
	//context->st->pipe->priv = context;

	return B_OK;
}


status_t
GalliumContext::SwapBuffers(context_id contextID)
{
	CALLED();

	Lock();
	struct hgl_context *context = fContext[contextID];
	Unlock();

	if (!context) {
		ERROR("%s: context not found\n", __func__);
		return B_ERROR;
	}

	// TODO: Where did st_notify_swapbuffers go?
	//st_notify_swapbuffers(context->draw->stfbi);

	context->st->flush(context->st, ST_FLUSH_FRONT, NULL);

	struct st_context *stContext = (struct st_context*)context->st;

	unsigned nColorBuffers = stContext->state.framebuffer.nr_cbufs;
	for (unsigned i = 0; i < nColorBuffers; i++) {
		pipe_surface* surface = stContext->state.framebuffer.cbufs[i];
		if (!surface) {
			ERROR("%s: Color buffer %d invalid!\n", __func__, i);
			continue;
		}

		TRACE("%s: Flushing color buffer #%d\n", __func__, i);

		// We pass our destination bitmap to flush_fronbuffer which passes it
		// to the private winsys display call.
		fScreen->flush_frontbuffer(fScreen, surface->texture, 0, 0,
			context->bitmap, NULL);
	}

	#if 0
	// TODO... should we flush the z stencil buffer?
	pipe_surface* zSurface = stContext->state.framebuffer.zsbuf;
	fScreen->flush_frontbuffer(fScreen, zSurface->texture, 0, 0,
		context->bitmap, NULL);
	#endif

	return B_OK;
}


bool
GalliumContext::Validate(uint32 width, uint32 height)
{
	CALLED();

	if (!fContext[fCurrentContext]) {
		return false;
	}

	if (fContext[fCurrentContext]->width != width
		|| fContext[fCurrentContext]->height != height) {
		Invalidate(width, height);
		return false;
	}
	return true;
}


void
GalliumContext::Invalidate(uint32 width, uint32 height)
{
	CALLED();

	assert(fContext[fCurrentContext]);

	// Update st_context dimensions 
	fContext[fCurrentContext]->width = width;
	fContext[fCurrentContext]->height = height;

	// Is this the best way to invalidate?
	p_atomic_inc(&fContext[fCurrentContext]->read->stfbi->stamp);
	p_atomic_inc(&fContext[fCurrentContext]->draw->stfbi->stamp);
}


void
GalliumContext::Lock()
{
	CALLED();
	mtx_lock(&fMutex);
}


void
GalliumContext::Unlock()
{
	CALLED();
	mtx_unlock(&fMutex);
}
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