flycast/core/rend/gles/gldraw.cpp

#include "glcache.h"
#include "gles.h"
#include "rend/sorter.h"

/*

Drawing and related state management
Takes vertex, textures and renders to the currently set up target

*/

const static u32 CullMode[]= 
{
	GL_NONE, //0    No culling          No culling
	GL_NONE, //1    Cull if Small       Cull if ( |det| < fpu_cull_val )

	GL_FRONT, //2   Cull if Negative    Cull if ( |det| < 0 ) or ( |det| < fpu_cull_val )
	GL_BACK,  //3   Cull if Positive    Cull if ( |det| > 0 ) or ( |det| < fpu_cull_val )
};
const u32 Zfunction[] =
{
	GL_NEVER,       //0 Never
	GL_LESS,        //1 Less
	GL_EQUAL,       //2 Equal
	GL_LEQUAL,      //3 Less Or Equal
	GL_GREATER,     //4 Greater
	GL_NOTEQUAL,    //5 Not Equal
	GL_GEQUAL,      //6 Greater Or Equal
	GL_ALWAYS,      //7 Always
};

/*
0   Zero                  (0, 0, 0, 0)
1   One                   (1, 1, 1, 1)
2   Other Color           (OR, OG, OB, OA)
3   Inverse Other Color   (1-OR, 1-OG, 1-OB, 1-OA)
4   SRC Alpha             (SA, SA, SA, SA)
5   Inverse SRC Alpha     (1-SA, 1-SA, 1-SA, 1-SA)
6   DST Alpha             (DA, DA, DA, DA)
7   Inverse DST Alpha     (1-DA, 1-DA, 1-DA, 1-DA)
*/

const u32 DstBlendGL[] =
{
	GL_ZERO,
	GL_ONE,
	GL_SRC_COLOR,
	GL_ONE_MINUS_SRC_COLOR,
	GL_SRC_ALPHA,
	GL_ONE_MINUS_SRC_ALPHA,
	GL_DST_ALPHA,
	GL_ONE_MINUS_DST_ALPHA
};

const u32 SrcBlendGL[] =
{
	GL_ZERO,
	GL_ONE,
	GL_DST_COLOR,
	GL_ONE_MINUS_DST_COLOR,
	GL_SRC_ALPHA,
	GL_ONE_MINUS_SRC_ALPHA,
	GL_DST_ALPHA,
	GL_ONE_MINUS_DST_ALPHA
};

extern int screen_width;
extern int screen_height;

PipelineShader* CurrentShader;
u32 gcflip;

s32 SetTileClip(u32 val, GLint uniform)
{
	if (!settings.rend.Clipping)
		return 0;

	u32 clipmode = val >> 28;
	s32 clip_mode;
	if (clipmode < 2)
		clip_mode = 0;    //always passes
	else if (clipmode & 1)
		clip_mode = -1;   //render stuff outside the region
	else
		clip_mode = 1;    //render stuff inside the region

	float csx = val & 63;
	float cex = (val >> 6) & 63;
	float csy = (val >> 12) & 31;
	float cey = (val >> 17) & 31;
	csx = csx * 32;
	cex = cex * 32 + 32;
	csy = csy * 32;
	cey = cey * 32 + 32;

	if (csx <= 0 && csy <= 0 && cex >= 640 && cey >= 480)
		return 0;

	if (uniform >= 0 && clip_mode)
	{
		if (!pvrrc.isRTT)
		{
			glm::vec4 clip_start(csx, csy, 0, 1);
			glm::vec4 clip_end(cex, cey, 0, 1);
			clip_start = ViewportMatrix * clip_start;
			clip_end = ViewportMatrix * clip_end;

			csx = clip_start[0];
			csy = clip_start[1];
			cey = clip_end[1];
			cex = clip_end[0];
		}
		else if (!settings.rend.RenderToTextureBuffer)
		{
			csx *= settings.rend.RenderToTextureUpscale;
			csy *= settings.rend.RenderToTextureUpscale;
			cex *= settings.rend.RenderToTextureUpscale;
			cey *= settings.rend.RenderToTextureUpscale;
		}
		glUniform4f(uniform, std::min(csx, cex), std::min(csy, cey), std::max(csx, cex), std::max(csy, cey));
	}

	return clip_mode;
}

void SetCull(u32 CulliMode)
{
	if (CullMode[CulliMode]==GL_NONE)
		glcache.Disable(GL_CULL_FACE);
	else
	{
		glcache.Enable(GL_CULL_FACE);
		glcache.CullFace(CullMode[CulliMode]); //GL_FRONT/GL_BACK, ...
	}
}

static void SetTextureRepeatMode(GLuint dir, u32 clamp, u32 mirror)
{
	if (clamp)
		glcache.TexParameteri(GL_TEXTURE_2D, dir, GL_CLAMP_TO_EDGE);
	else
		glcache.TexParameteri(GL_TEXTURE_2D, dir, mirror ? GL_MIRRORED_REPEAT : GL_REPEAT);
}

template <u32 Type, bool SortingEnabled>
__forceinline
	void SetGPState(const PolyParam* gp,u32 cflip=0)
{
	if (gp->pcw.Texture && gp->tsp.FilterMode > 1 && Type != ListType_Punch_Through && gp->tcw.MipMapped == 1)
	{
		ShaderUniforms.trilinear_alpha = 0.25 * (gp->tsp.MipMapD & 0x3);
		if (gp->tsp.FilterMode == 2)
			// Trilinear pass A
			ShaderUniforms.trilinear_alpha = 1.0 - ShaderUniforms.trilinear_alpha;
	}
	else
		ShaderUniforms.trilinear_alpha = 1.f;

	bool color_clamp = gp->tsp.ColorClamp && (pvrrc.fog_clamp_min != 0 || pvrrc.fog_clamp_max != 0xffffffff);
	int fog_ctrl = settings.rend.Fog ? gp->tsp.FogCtrl : 2;

	CurrentShader = GetProgram(Type == ListType_Punch_Through ? 1 : 0,
								  SetTileClip(gp->tileclip, -1) + 1,
								  gp->pcw.Texture,
								  gp->tsp.UseAlpha,
								  gp->tsp.IgnoreTexA,
								  gp->tsp.ShadInstr,
								  gp->pcw.Offset,
								  fog_ctrl,
								  gp->pcw.Gouraud,
								  gp->tcw.PixelFmt == PixelBumpMap,
								  color_clamp,
								  ShaderUniforms.trilinear_alpha != 1.f);
	
	glcache.UseProgram(CurrentShader->program);
	if (CurrentShader->trilinear_alpha != -1)
		glUniform1f(CurrentShader->trilinear_alpha, ShaderUniforms.trilinear_alpha);

	SetTileClip(gp->tileclip, CurrentShader->pp_ClipTest);

	//This bit control which pixels are affected
	//by modvols
	const u32 stencil=(gp->pcw.Shadow!=0)?0x80:0x0;

	glcache.StencilFunc(GL_ALWAYS,stencil,stencil);

	glcache.BindTexture(GL_TEXTURE_2D, gp->texid == -1 ? 0 : (GLuint)gp->texid);

	SetTextureRepeatMode(GL_TEXTURE_WRAP_S, gp->tsp.ClampU, gp->tsp.FlipU);
	SetTextureRepeatMode(GL_TEXTURE_WRAP_T, gp->tsp.ClampV, gp->tsp.FlipV);

	//set texture filter mode
	if (gp->tsp.FilterMode == 0)
	{
		//disable filtering, mipmaps
		glcache.TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
		glcache.TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	}
	else
	{
		//bilinear filtering
		//PowerVR supports also trilinear via two passes, but we ignore that for now
		bool mipmapped = gp->tcw.MipMapped != 0 && gp->tcw.ScanOrder == 0 && settings.rend.UseMipmaps;
		glcache.TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, mipmapped ? GL_LINEAR_MIPMAP_NEAREST : GL_LINEAR);
		glcache.TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
#ifdef GL_TEXTURE_LOD_BIAS
		if (!gl.is_gles && gl.gl_major >= 3 && mipmapped)
			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_LOD_BIAS, D_Adjust_LoD_Bias[gp->tsp.MipMapD]);
#endif
	}

	// Apparently punch-through polys support blending, or at least some combinations
	if (Type == ListType_Translucent || Type == ListType_Punch_Through)
	{
		glcache.Enable(GL_BLEND);
		glcache.BlendFunc(SrcBlendGL[gp->tsp.SrcInstr],DstBlendGL[gp->tsp.DstInstr]);
	}
	else
		glcache.Disable(GL_BLEND);

	//set cull mode !
	//cflip is required when exploding triangles for triangle sorting
	//gcflip is global clip flip, needed for when rendering to texture due to mirrored Y direction
	SetCull(gp->isp.CullMode^cflip^gcflip);

	//set Z mode, only if required
	if (Type == ListType_Punch_Through || (Type == ListType_Translucent && SortingEnabled))
	{
		glcache.DepthFunc(GL_GEQUAL);
	}
	else
	{
		glcache.DepthFunc(Zfunction[gp->isp.DepthMode]);
	}

	if (SortingEnabled && !settings.rend.PerStripSorting)
		glcache.DepthMask(GL_FALSE);
	else
	{
		// Z Write Disable seems to be ignored for punch-through.
		// Fixes Worms World Party, Bust-a-Move 4 and Re-Volt
		if (Type == ListType_Punch_Through)
			glcache.DepthMask(GL_TRUE);
		else
			glcache.DepthMask(!gp->isp.ZWriteDis);
	}
}

template <u32 Type, bool SortingEnabled>
void DrawList(const List<PolyParam>& gply, int first, int count)
{
	PolyParam* params = &gply.head()[first];


	if (count==0)
		return;
	//we want at least 1 PParam


	//set some 'global' modes for all primitives

	glcache.Enable(GL_STENCIL_TEST);
	glcache.StencilFunc(GL_ALWAYS,0,0);
	glcache.StencilOp(GL_KEEP,GL_KEEP,GL_REPLACE);

	while(count-->0)
	{
		if (params->count>2) //this actually happens for some games. No idea why ..
		{
			if ((Type == ListType_Opaque || (Type == ListType_Translucent && !SortingEnabled)) && params->isp.DepthMode == 0)
			{
				// depthFunc = never
				params++;
				continue;
			}
			SetGPState<Type,SortingEnabled>(params);
			glDrawElements(GL_TRIANGLE_STRIP, params->count, gl.index_type,
					(GLvoid*)(gl.get_index_size() * params->first)); glCheck();
		}

		params++;
	}
}

static vector<SortTrigDrawParam> pidx_sort;

static void SortTriangles(int first, int count)
{
	vector<u32> vidx_sort;
	GenSorted(first, count, pidx_sort, vidx_sort);

	//Upload to GPU if needed
	if (pidx_sort.size())
	{
		//Bind and upload sorted index buffer
		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, gl.vbo.idxs2); glCheck();
		if (gl.index_type == GL_UNSIGNED_SHORT)
		{
			static bool overrun;
			static List<u16> short_vidx;
			if (short_vidx.daty != NULL)
				short_vidx.Free();
			short_vidx.Init(vidx_sort.size(), &overrun, NULL);
			for (int i = 0; i < vidx_sort.size(); i++)
				*(short_vidx.Append()) = vidx_sort[i];
			glBufferData(GL_ELEMENT_ARRAY_BUFFER, short_vidx.bytes(), short_vidx.head(), GL_STREAM_DRAW);
		}
		else
			glBufferData(GL_ELEMENT_ARRAY_BUFFER, vidx_sort.size() * sizeof(u32), &vidx_sort[0], GL_STREAM_DRAW);
		glCheck();
	}
}

void DrawSorted(bool multipass)
{
	//if any drawing commands, draw them
	if (pidx_sort.size())
	{
		u32 count=pidx_sort.size();
		
		{
			//set some 'global' modes for all primitives

			glcache.Enable(GL_STENCIL_TEST);
			glcache.StencilFunc(GL_ALWAYS,0,0);
			glcache.StencilOp(GL_KEEP,GL_KEEP,GL_REPLACE);

			for (u32 p=0; p<count; p++)
			{
				const PolyParam* params = pidx_sort[p].ppid;
				if (pidx_sort[p].count>2) //this actually happens for some games. No idea why ..
				{
					SetGPState<ListType_Translucent,true>(params);
					glDrawElements(GL_TRIANGLES, pidx_sort[p].count, gl.index_type,
							(GLvoid*)(gl.get_index_size() * pidx_sort[p].first)); glCheck();
				
#if 0
					//Verify restriping -- only valid if no sort
					int fs=pidx_sort[p].first;

					for (u32 j=0; j<(params->count-2); j++)
					{
						for (u32 k=0; k<3; k++)
						{
							verify(idx_base[params->first+j+k]==vidx_sort[fs++]);
						}
					}

					verify(fs==(pidx_sort[p].first+pidx_sort[p].count));
#endif
				}
				params++;
			}

			if (multipass && settings.rend.TranslucentPolygonDepthMask)
			{
				// Write to the depth buffer now. The next render pass might need it. (Cosmic Smash)
				glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
				glcache.Disable(GL_BLEND);

				glcache.StencilMask(0);

				// We use the modifier volumes shader because it's fast. We don't need textures, etc.
				glcache.UseProgram(gl.modvol_shader.program);
				glUniform1f(gl.modvol_shader.sp_ShaderColor, 1.f);

				glcache.DepthFunc(GL_GEQUAL);
				glcache.DepthMask(GL_TRUE);

				for (u32 p = 0; p < count; p++)
				{
					const PolyParam* params = pidx_sort[p].ppid;
					if (pidx_sort[p].count > 2 && !params->isp.ZWriteDis) {
						// FIXME no clipping in modvol shader
						//SetTileClip(gp->tileclip,true);

						SetCull(params->isp.CullMode ^ gcflip);

						glDrawElements(GL_TRIANGLES, pidx_sort[p].count, gl.index_type,
								(GLvoid*)(gl.get_index_size() * pidx_sort[p].first));
					}
				}
				glcache.StencilMask(0xFF);
				glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
			}
		}
		// Re-bind the previous index buffer for subsequent render passes
		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, gl.vbo.idxs);
	}
}

//All pixels are in area 0 by default.
//If inside an 'in' volume, they are in area 1
//if inside an 'out' volume, they are in area 0
/*
	Stencil bits:
		bit 7: mv affected (must be preserved)
		bit 1: current volume state
		but 0: summary result (starts off as 0)

	Lower 2 bits:

	IN volume (logical OR):
	00 -> 00
	01 -> 01
	10 -> 01
	11 -> 01

	Out volume (logical AND):
	00 -> 00
	01 -> 00
	10 -> 00
	11 -> 01
*/
void SetMVS_Mode(ModifierVolumeMode mv_mode, ISP_Modvol ispc)
{
	if (mv_mode == Xor)
	{
		// set states
		glcache.Enable(GL_DEPTH_TEST);
		// write only bit 1
		glcache.StencilMask(2);
		// no stencil testing
		glcache.StencilFunc(GL_ALWAYS, 0, 2);
		// count the number of pixels in front of the Z buffer (xor zpass)
		glcache.StencilOp(GL_KEEP, GL_KEEP, GL_INVERT);

		// Cull mode needs to be set
		SetCull(ispc.CullMode);
	}
	else if (mv_mode == Or)
	{
		// set states
		glcache.Enable(GL_DEPTH_TEST);
		// write only bit 1
		glcache.StencilMask(2);
		// no stencil testing
		glcache.StencilFunc(GL_ALWAYS, 2, 2);
		// Or'ing of all triangles
		glcache.StencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);

		// Cull mode needs to be set
		SetCull(ispc.CullMode);
	}
	else
	{
		// Inclusion or Exclusion volume

		// no depth test
		glcache.Disable(GL_DEPTH_TEST);
		// write bits 1:0
		glcache.StencilMask(3);

		if (mv_mode == Inclusion)
		{
			// Inclusion volume
			//res : old : final 
			//0   : 0      : 00
			//0   : 1      : 01
			//1   : 0      : 01
			//1   : 1      : 01
			
			// if (1<=st) st=1; else st=0;
			glcache.StencilFunc(GL_LEQUAL,1,3);
			glcache.StencilOp(GL_ZERO, GL_ZERO, GL_REPLACE);
		}
		else
		{
			// Exclusion volume
			/*
				I've only seen a single game use it, so i guess it doesn't matter ? (Zombie revenge)
				(actually, i think there was also another, racing game)
			*/
			// The initial value for exclusion volumes is 1 so we need to invert the result before and'ing.
			//res : old : final 
			//0   : 0   : 00
			//0   : 1   : 01
			//1   : 0   : 00
			//1   : 1   : 00

			// if (1 == st) st = 1; else st = 0;
			glcache.StencilFunc(GL_EQUAL, 1, 3);
			glcache.StencilOp(GL_ZERO, GL_ZERO, GL_KEEP);
		}
	}
}


static void SetupMainVBO()
{
#ifndef GLES2
	if (gl.gl_major >= 3)
		glBindVertexArray(gl.vbo.vao);
#endif
	glBindBuffer(GL_ARRAY_BUFFER, gl.vbo.geometry); glCheck();
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, gl.vbo.idxs); glCheck();

	//setup vertex buffers attrib pointers
	glEnableVertexAttribArray(VERTEX_POS_ARRAY); glCheck();
	glVertexAttribPointer(VERTEX_POS_ARRAY, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex,x)); glCheck();

	glEnableVertexAttribArray(VERTEX_COL_BASE_ARRAY); glCheck();
	glVertexAttribPointer(VERTEX_COL_BASE_ARRAY, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(Vertex), (void*)offsetof(Vertex,col)); glCheck();

	glEnableVertexAttribArray(VERTEX_COL_OFFS_ARRAY); glCheck();
	glVertexAttribPointer(VERTEX_COL_OFFS_ARRAY, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(Vertex), (void*)offsetof(Vertex,spc)); glCheck();

	glEnableVertexAttribArray(VERTEX_UV_ARRAY); glCheck();
	glVertexAttribPointer(VERTEX_UV_ARRAY, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex,u)); glCheck();
}

void SetupModvolVBO()
{
#ifndef GLES2
	if (gl.gl_major >= 3)
		glBindVertexArray(gl.vbo.vao);
#endif
	glBindBuffer(GL_ARRAY_BUFFER, gl.vbo.modvols); glCheck();

	//setup vertex buffers attrib pointers
	glEnableVertexAttribArray(VERTEX_POS_ARRAY); glCheck();
	glVertexAttribPointer(VERTEX_POS_ARRAY, 3, GL_FLOAT, GL_FALSE, sizeof(float)*3, (void*)0); glCheck();

	glDisableVertexAttribArray(VERTEX_UV_ARRAY);
	glDisableVertexAttribArray(VERTEX_COL_OFFS_ARRAY);
	glDisableVertexAttribArray(VERTEX_COL_BASE_ARRAY);
}
void DrawModVols(int first, int count)
{
	if (count == 0 || pvrrc.modtrig.used() == 0)
		return;

	SetupModvolVBO();

	glcache.Disable(GL_BLEND);

	glcache.UseProgram(gl.modvol_shader.program);
	glUniform1f(gl.modvol_shader.sp_ShaderColor, 1 - FPU_SHAD_SCALE.scale_factor / 256.f);

	glcache.Enable(GL_DEPTH_TEST);
	glcache.DepthMask(GL_FALSE);
	glcache.DepthFunc(GL_GREATER);

	glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);

	ModifierVolumeParam* params = &pvrrc.global_param_mvo.head()[first];

	int mod_base = -1;

	for (u32 cmv = 0; cmv < count; cmv++)
	{
		ModifierVolumeParam& param = params[cmv];

		if (param.count == 0)
			continue;

		u32 mv_mode = param.isp.DepthMode;

		if (mod_base == -1)
			mod_base = param.first;

		if (!param.isp.VolumeLast && mv_mode > 0)
			SetMVS_Mode(Or, param.isp);		// OR'ing (open volume or quad)
		else
			SetMVS_Mode(Xor, param.isp);	// XOR'ing (closed volume)

		glDrawArrays(GL_TRIANGLES, param.first * 3, param.count * 3);

		if (mv_mode == 1 || mv_mode == 2)
		{
			// Sum the area
			SetMVS_Mode(mv_mode == 1 ? Inclusion : Exclusion, param.isp);
			glDrawArrays(GL_TRIANGLES, mod_base * 3, (param.first + param.count - mod_base) * 3);
			mod_base = -1;
		}
	}
	//disable culling
	SetCull(0);
	//enable color writes
	glColorMask(GL_TRUE,GL_TRUE,GL_TRUE,GL_TRUE);

	//black out any stencil with '1'
	glcache.Enable(GL_BLEND);
	glcache.BlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);

	glcache.Enable(GL_STENCIL_TEST);
	glcache.StencilFunc(GL_EQUAL,0x81,0x81); //only pixels that are Modvol enabled, and in area 1

	//clear the stencil result bit
	glcache.StencilMask(0x3);    //write to lsb
	glcache.StencilOp(GL_ZERO,GL_ZERO,GL_ZERO);

	//don't do depth testing
	glcache.Disable(GL_DEPTH_TEST);

	SetupMainVBO();
	glDrawArrays(GL_TRIANGLE_STRIP,0,4);

	//restore states
	glcache.Enable(GL_DEPTH_TEST);
}

void DrawStrips()
{
	SetupMainVBO();
	//Draw the strips !

	//We use sampler 0
	glActiveTexture(GL_TEXTURE0);

	RenderPass previous_pass = {};
    for (int render_pass = 0; render_pass < pvrrc.render_passes.used(); render_pass++) {
        const RenderPass& current_pass = pvrrc.render_passes.head()[render_pass];

        DEBUG_LOG(RENDERER, "Render pass %d OP %d PT %d TR %d MV %d", render_pass + 1,
        		current_pass.op_count - previous_pass.op_count,
				current_pass.pt_count - previous_pass.pt_count,
				current_pass.tr_count - previous_pass.tr_count,
				current_pass.mvo_count - previous_pass.mvo_count);

		//initial state
		glcache.Enable(GL_DEPTH_TEST);
		glcache.DepthMask(GL_TRUE);

		//Opaque
		DrawList<ListType_Opaque,false>(pvrrc.global_param_op, previous_pass.op_count, current_pass.op_count - previous_pass.op_count);

		//Alpha tested
		DrawList<ListType_Punch_Through,false>(pvrrc.global_param_pt, previous_pass.pt_count, current_pass.pt_count - previous_pass.pt_count);

		// Modifier volumes
		if (settings.rend.ModifierVolumes)
			DrawModVols(previous_pass.mvo_count, current_pass.mvo_count - previous_pass.mvo_count);

		//Alpha blended
		{
			if (current_pass.autosort)
            {
				if (!settings.rend.PerStripSorting)
				{
					SortTriangles(previous_pass.tr_count, current_pass.tr_count - previous_pass.tr_count);
					DrawSorted(render_pass < pvrrc.render_passes.used() - 1);
				}
				else
				{
					SortPParams(previous_pass.tr_count, current_pass.tr_count - previous_pass.tr_count);
					DrawList<ListType_Translucent,true>(pvrrc.global_param_tr, previous_pass.tr_count, current_pass.tr_count - previous_pass.tr_count);
				}
            }
			else
				DrawList<ListType_Translucent,false>(pvrrc.global_param_tr, previous_pass.tr_count, current_pass.tr_count - previous_pass.tr_count);
		}
		previous_pass = current_pass;
	}
}

static void DrawQuad(GLuint texId, float x, float y, float w, float h, float u0, float v0, float u1, float v1)
{
	struct Vertex vertices[] = {
		{ x,     y + h, 0.1, { 255, 255, 255, 255 }, { 0, 0, 0, 0 }, u0, v1 },
		{ x,     y,     0.1, { 255, 255, 255, 255 }, { 0, 0, 0, 0 }, u0, v0 },
		{ x + w, y + h, 0.1, { 255, 255, 255, 255 }, { 0, 0, 0, 0 }, u1, v1 },
		{ x + w, y,     0.1, { 255, 255, 255, 255 }, { 0, 0, 0, 0 }, u1, v0 },
	};
	GLushort indices[] = { 0, 1, 2, 1, 3 };

	glcache.Disable(GL_SCISSOR_TEST);
	glcache.Disable(GL_DEPTH_TEST);
	glcache.Disable(GL_STENCIL_TEST);
	glcache.Disable(GL_CULL_FACE);
	glcache.Disable(GL_BLEND);

	ShaderUniforms.trilinear_alpha = 1.0;

	PipelineShader *shader = GetProgram(0, 1, 1, 0, 1, 0, 0, 2, false, false, false, false);
	glcache.UseProgram(shader->program);

	glActiveTexture(GL_TEXTURE0);
	glcache.BindTexture(GL_TEXTURE_2D, texId);

	SetupMainVBO();
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STREAM_DRAW);
	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STREAM_DRAW);

	glDrawElements(GL_TRIANGLE_STRIP, 5, GL_UNSIGNED_SHORT, (void *)0);
}

void DrawFramebuffer()
{
	DrawQuad(fbTextureId, 0, 0, 640.f, 480.f, 0, 0, 1, 1);
	glcache.DeleteTextures(1, &fbTextureId);
	fbTextureId = 0;
}

bool render_output_framebuffer()
{
	glcache.Disable(GL_SCISSOR_TEST);
	if (gl.gl_major < 3)
	{
		glViewport(0, 0, screen_width, screen_height);
		if (gl.ofbo.tex == 0)
			return false;
		glBindFramebuffer(GL_FRAMEBUFFER, 0);
		float scl = 480.f / screen_height;
		float tx = (screen_width * scl - 640.f) / 2;
		DrawQuad(gl.ofbo.tex, -tx, 0, 640.f + tx * 2, 480.f, 0, 1, 1, 0);
	}
	else
	{
#ifndef GLES2
		if (gl.ofbo.fbo == 0)
			return false;
		glBindFramebuffer(GL_READ_FRAMEBUFFER, gl.ofbo.fbo);
		glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
		glBlitFramebuffer(0, 0, gl.ofbo.width, gl.ofbo.height,
				0, 0, screen_width, screen_height,
				GL_COLOR_BUFFER_BIT, GL_LINEAR);
    	glBindFramebuffer(GL_FRAMEBUFFER, 0);
#endif
	}
	return true;
}