#include "context.h"

C3D_Context __C3D_Context;

static void C3Di_SetTex(GPU_TEXUNIT unit, C3D_Tex* tex)
{
	u32 reg[4];
	reg[0] = tex->fmt;
	reg[1] = osConvertVirtToPhys((u32)tex->data) >> 3;
	reg[2] = (u32)tex->height | ((u32)tex->width << 16);
	reg[3] = tex->param;

	switch (unit)
	{
		case GPU_TEXUNIT0:
			GPUCMD_AddWrite(GPUREG_TEXUNIT0_TYPE, reg[0]);
			GPUCMD_AddWrite(GPUREG_TEXUNIT0_LOC, reg[1]);
			GPUCMD_AddWrite(GPUREG_TEXUNIT0_DIM, reg[2]);
			GPUCMD_AddWrite(GPUREG_TEXUNIT0_PARAM, reg[3]);
			break;
		case GPU_TEXUNIT1:
			GPUCMD_AddWrite(GPUREG_TEXUNIT1_TYPE, reg[0]);
			GPUCMD_AddWrite(GPUREG_TEXUNIT1_LOC, reg[1]);
			GPUCMD_AddWrite(GPUREG_TEXUNIT1_DIM, reg[2]);
			GPUCMD_AddWrite(GPUREG_TEXUNIT1_PARAM, reg[3]);
			break;
		case GPU_TEXUNIT2:
			GPUCMD_AddWrite(GPUREG_TEXUNIT2_TYPE, reg[0]);
			GPUCMD_AddWrite(GPUREG_TEXUNIT2_LOC, reg[1]);
			GPUCMD_AddWrite(GPUREG_TEXUNIT2_DIM, reg[2]);
			GPUCMD_AddWrite(GPUREG_TEXUNIT2_PARAM, reg[3]);
			break;
	}
}

static aptHookCookie hookCookie;

static void C3Di_AptEventHook(int hookType, void* param)
{
	C3D_Context* ctx = C3Di_GetContext();

	switch (hookType)
	{
		case APTHOOK_ONSUSPEND:
		{
			break;
		}
		case APTHOOK_ONRESTORE:
		{
			ctx->flags |= C3DiF_AttrInfo | C3DiF_BufInfo | C3DiF_Effect | C3DiF_RenderBuf
				| C3DiF_Viewport | C3DiF_Scissor | C3DiF_Program
				| C3DiF_TexAll | C3DiF_TexEnvBuf | C3DiF_TexEnvAll | C3DiF_LightEnv;

			C3D_LightEnv* env = ctx->lightEnv;
			if (env)
				env->Dirty(env);
			break;
		}
	}
}

bool C3D_Init(size_t cmdBufSize)
{
	int i;
	C3D_Context* ctx = C3Di_GetContext();

	if (ctx->flags & C3DiF_Active)
		return false;

	ctx->cmdBufSize = cmdBufSize;
	ctx->cmdBuf = linearAlloc(cmdBufSize);
	if (!ctx->cmdBuf) return false;

	GPUCMD_SetBuffer(ctx->cmdBuf, ctx->cmdBufSize, 0);

	ctx->flags = C3DiF_Active | C3DiF_TexEnvBuf | C3DiF_TexEnvAll | C3DiF_Effect | C3DiF_TexAll;

	// TODO: replace with direct struct access
	C3D_DepthMap(-1.0f, 0.0f);
	C3D_CullFace(GPU_CULL_BACK_CCW);
	C3D_StencilTest(false, GPU_ALWAYS, 0x00, 0xFF, 0x00);
	C3D_StencilOp(GPU_STENCIL_KEEP, GPU_STENCIL_KEEP, GPU_STENCIL_KEEP);
	C3D_BlendingColor(0);
	C3D_DepthTest(true, GPU_GREATER, GPU_WRITE_ALL);
	C3D_AlphaTest(false, GPU_ALWAYS, 0x00);
	C3D_AlphaBlend(GPU_BLEND_ADD, GPU_BLEND_ADD, GPU_SRC_ALPHA, GPU_ONE_MINUS_SRC_ALPHA, GPU_SRC_ALPHA, GPU_ONE_MINUS_SRC_ALPHA);

	ctx->texEnvBuf = 0;
	ctx->texEnvBufClr = 0xFFFFFFFF;

	for (i = 0; i < 3; i ++)
		ctx->tex[i] = NULL;

	for (i = 0; i < 6; i ++)
		TexEnv_Init(&ctx->texEnv[i]);

	aptHook(&hookCookie, C3Di_AptEventHook, NULL);

	return true;
}

void C3D_SetViewport(u32 x, u32 y, u32 w, u32 h)
{
	C3D_Context* ctx = C3Di_GetContext();
	ctx->flags |= C3DiF_Viewport | C3DiF_Scissor;
	ctx->viewport[0] = f32tof24(w / 2.0f);
	ctx->viewport[1] = f32tof31(2.0f / w) << 1;
	ctx->viewport[2] = f32tof24(h / 2.0f);
	ctx->viewport[3] = f32tof31(2.0f / h) << 1;
	ctx->viewport[4] = (y << 16) | (x & 0xFFFF);
	ctx->scissor[0] = GPU_SCISSOR_DISABLE;
}

void C3D_SetScissor(GPU_SCISSORMODE mode, u32 x, u32 y, u32 w, u32 h)
{
	C3D_Context* ctx = C3Di_GetContext();
	ctx->flags |= C3DiF_Scissor;
	ctx->scissor[0] = mode;
	if (mode == GPU_SCISSOR_DISABLE) return;
	ctx->scissor[1] = (y << 16) | (x & 0xFFFF);
	ctx->scissor[2] = ((h-1) << 16) | ((w-1) & 0xFFFF);
}

void C3Di_UpdateContext(void)
{
	int i;
	C3D_Context* ctx = C3Di_GetContext();

	if (ctx->flags & C3DiF_NeedFinishDrawing)
	{
		ctx->flags &= ~C3DiF_NeedFinishDrawing;
		//GPU_FinishDrawing();
	}

	if (ctx->flags & C3DiF_Program)
	{
		ctx->flags &= ~C3DiF_Program;
		shaderProgramUse(ctx->program);
	}

	if (ctx->flags & C3DiF_RenderBuf)
	{
		ctx->flags &= ~C3DiF_RenderBuf;
		C3Di_RenderBufBind(ctx->rb);
	}

	if (ctx->flags & C3DiF_Viewport)
	{
		ctx->flags &= ~C3DiF_Viewport;
		GPUCMD_AddIncrementalWrites(GPUREG_VIEWPORT_WIDTH, ctx->viewport, 4);
		GPUCMD_AddWrite(GPUREG_VIEWPORT_XY, ctx->viewport[4]);
	}

	if (ctx->flags & C3DiF_Scissor)
	{
		ctx->flags &= ~C3DiF_Scissor;
		GPUCMD_AddIncrementalWrites(GPUREG_SCISSORTEST_MODE, ctx->scissor, 3);
	}

	if (ctx->flags & C3DiF_AttrInfo)
	{
		ctx->flags &= ~C3DiF_AttrInfo;
		C3Di_AttrInfoBind(&ctx->attrInfo);
	}

	if (ctx->flags & C3DiF_BufInfo)
	{
		ctx->flags &= ~C3DiF_BufInfo;
		C3Di_BufInfoBind(&ctx->bufInfo);
	}

	if (ctx->flags & C3DiF_Effect)
	{
		ctx->flags &= ~C3DiF_Effect;
		C3Di_EffectBind(&ctx->effect);
	}

	if (ctx->flags & C3DiF_TexAll)
	{
		GPU_TEXUNIT units = 0;

		for (i = 0; i < 3; i ++)
		{
			static const u8 parm[] = { GPU_TEXUNIT0, GPU_TEXUNIT1, GPU_TEXUNIT2 };

			if (ctx->tex[i])
			{
				units |= parm[i];
				if (ctx->flags & C3DiF_Tex(i))
					C3Di_SetTex(parm[i], ctx->tex[i]);
			}
		}

		ctx->flags &= ~C3DiF_TexAll;
		GPUCMD_AddMaskedWrite(GPUREG_006F, 0x2, units<<8);        // enables texcoord outputs
		GPUCMD_AddWrite(GPUREG_TEXUNIT_ENABLE, 0x00011000|units); // enables texture units
	}

	if (ctx->flags & C3DiF_TexEnvBuf)
	{
		ctx->flags &= ~C3DiF_TexEnvBuf;
		GPUCMD_AddMaskedWrite(GPUREG_TEXENV_UPDATE_BUFFER, 0x2, ctx->texEnvBuf);
		GPUCMD_AddWrite(GPUREG_TEXENV_BUFFER_COLOR, ctx->texEnvBufClr);
	}

	if (ctx->flags & C3DiF_TexEnvAll)
	{
		for (i = 0; i < 6; i ++)
		{
			if (!(ctx->flags & C3DiF_TexEnv(i))) continue;
			C3Di_TexEnvBind(i, &ctx->texEnv[i]);
		}
		ctx->flags &= ~C3DiF_TexEnvAll;
	}

	C3D_LightEnv* env = ctx->lightEnv;

	if (ctx->flags & C3DiF_LightEnv)
	{
		u32 enable = env != NULL;
		GPUCMD_AddWrite(GPUREG_LIGHTING_ENABLE0, enable);
		GPUCMD_AddWrite(GPUREG_LIGHTING_ENABLE1, !enable);
		ctx->flags &= ~C3DiF_LightEnv;
	}

	if (env)
		env->Update(env);

	C3D_UpdateUniforms(GPU_VERTEX_SHADER);
	C3D_UpdateUniforms(GPU_GEOMETRY_SHADER);
}

void C3D_FlushAsync(void)
{
	C3D_Context* ctx = C3Di_GetContext();

	if (!(ctx->flags & C3DiF_Active))
		return;

	if (ctx->flags & C3DiF_NeedFinishDrawing)
	{
		ctx->flags &= ~C3DiF_NeedFinishDrawing;
		GPUCMD_AddWrite(GPUREG_FRAMEBUFFER_FLUSH, 0x00000001);
		GPUCMD_AddWrite(GPUREG_FRAMEBUFFER_INVALIDATE, 0x00000001);
		GPUCMD_AddWrite(GPUREG_0063, 0x00000001);
	}

	GPUCMD_Finalize();
	GPUCMD_FlushAndRun();
	GPUCMD_SetBuffer(ctx->cmdBuf, ctx->cmdBufSize, 0);
}

void C3D_Fini(void)
{
	C3D_Context* ctx = C3Di_GetContext();

	if (!(ctx->flags & C3DiF_Active))
		return;

	aptUnhook(&hookCookie);
	linearFree(ctx->cmdBuf);
	ctx->flags = 0;
}

void C3D_BindProgram(shaderProgram_s* program)
{
	C3D_Context* ctx = C3Di_GetContext();

	if (!(ctx->flags & C3DiF_Active))
		return;

	ctx->program = program;
	ctx->flags |= C3DiF_Program;
}