/*
 * mii_mui_gl.c
 *
 * Copyright (C) 2024 Michel Pollet <buserror@gmail.com>
 *
 * SPDX-License-Identifier: MIT
 */

/*
 * This contains OpenGL code, no x11 or GLx allowed in here, this is to be
 * used by a native windowing system, or a portable one like SDL2 or GLFW
 */

#include <stdio.h>
#include <stdlib.h>
#include <GL/gl.h>

#ifdef __SSE2__
#include <emmintrin.h> // SSE2 intrinsics
#endif

#include "mii_mui_gl.h"
#include "mii_floppy.h"


typedef struct c2_rect_f {
	float l,t,r,b;
} c2_rect_f;

#define MII_GL_FLOPPY_SEGMENT_COUNT 	32

#define MII_GL_FLOPPY_DISC_RADIUS_IN 	1.8
#define MII_GL_FLOPPY_DISC_RADIUS_OUT 	10
#define MII_GL_FLOPPY_FLUX_RADIUS_IN 	2.0
#define MII_GL_FLOPPY_FLUX_RADIUS_OUT 	9.8


#include <math.h>

static void
mii_gl_make_disc(
		float_array_t * pos,
		const double radius_out,
		const double radius_in,
		const int count)
{
	float_array_clear(pos);

	const double astep = 2 * M_PI / count; // Angle step for each blade

	for (int i = 0; i < MII_GL_FLOPPY_SEGMENT_COUNT; ++i) {
		double a = i * astep, b = (i + 1) * astep;
		// Outer vertex
		double x_out = radius_out * cos(a);
		double y_out = radius_out * sin(a);
		double x_out2 = radius_out * cos(b);
		double y_out2 = radius_out * sin(b);
		// Inner vertex
		double x_in = radius_in * cos(a);
		double y_in = radius_in * sin(a);
		double x_in2 = radius_in * cos(b);
		double y_in2 = radius_in * sin(b);
		// add two triangles winded in the right direction
		float_array_push(pos, x_out); float_array_push(pos, y_out);
		float_array_push(pos, x_in); float_array_push(pos, y_in);
		float_array_push(pos, x_out2); float_array_push(pos, y_out2);

		float_array_push(pos, x_in2); float_array_push(pos, y_in2);
		float_array_push(pos, x_out2); float_array_push(pos, y_out2);
		float_array_push(pos, x_in); float_array_push(pos, y_in);
	}
}
static void
mii_gl_make_floppy(
	mii_vtx_t	* 	vtx,
	float 			tex_width,
	bool 			do_pos,
	bool 			do_tex)
{
	vtx->kind = GL_TRIANGLES;
	if (do_pos) {
		mii_gl_make_disc(&vtx->pos,
				MII_GL_FLOPPY_FLUX_RADIUS_OUT,
				MII_GL_FLOPPY_FLUX_RADIUS_IN,
				MII_GL_FLOPPY_SEGMENT_COUNT);
	}
	if (!do_tex)
		return;
	const double tex_y_in = 1;
	const double tex_y_out = 0;
	float_array_t * tex = &vtx->tex;
	float_array_clear(tex);
	for (int i = 0; i < MII_GL_FLOPPY_SEGMENT_COUNT; ++i) {
		float_array_push(tex, (i * tex_width) / MII_GL_FLOPPY_SEGMENT_COUNT);
		float_array_push(tex, tex_y_out);
		float_array_push(tex, (i * tex_width) / MII_GL_FLOPPY_SEGMENT_COUNT);
		float_array_push(tex, tex_y_in);
		float_array_push(tex, ((i + 1) * tex_width) / MII_GL_FLOPPY_SEGMENT_COUNT);
		float_array_push(tex, tex_y_out);
		float_array_push(tex, ((i + 1) * tex_width) / MII_GL_FLOPPY_SEGMENT_COUNT);
		float_array_push(tex, tex_y_in);
		float_array_push(tex, ((i + 1) * tex_width) / MII_GL_FLOPPY_SEGMENT_COUNT);
		float_array_push(tex, tex_y_out);
		float_array_push(tex, (i * tex_width) / MII_GL_FLOPPY_SEGMENT_COUNT);
		float_array_push(tex, tex_y_in);
	}
}

void
mii_mui_gl_init(
		mii_mui_t *ui)
{
	GLuint tex[MII_PIXEL_LAYERS];
	glGenTextures(MII_PIXEL_LAYERS, tex);
	for (int i = 0; i < MII_PIXEL_LAYERS; i++) {
	//	printf("Texture %d created %d\n", i, tex[i]);
		ui->pixels.v[i].texture.id = tex[i];
		ui->tex_id[i] = tex[i];
	}
	mii_gl_make_disc(&ui->floppy_base,
			MII_GL_FLOPPY_DISC_RADIUS_OUT,
			MII_GL_FLOPPY_DISC_RADIUS_IN,
			MII_GL_FLOPPY_SEGMENT_COUNT);
	mii_mui_gl_prepare_textures(ui);
}

static void
_prep_grayscale_texture(
	mui_drawable_t * dr)
{
	dr->texture.size = dr->pix.size;
//	printf("Creating texture %4d %4dx%3d row_byte %4d\n",
//			dr->texture.id, dr->pix.size.x, dr->pix.size.y, dr->pix.row_bytes);
	glBindTexture(GL_TEXTURE_2D, dr->texture.id);
//	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
//	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	dr->texture.kind = GL_LUMINANCE;
	glTexImage2D(GL_TEXTURE_2D, 0, 1,
			dr->pix.row_bytes, dr->texture.size.y, 0, dr->texture.kind,
			GL_UNSIGNED_BYTE,
			dr->pix.pixels);
}

void
mii_mui_gl_prepare_textures(
		mii_mui_t *ui)
{
	mii_t * mii = &ui->mii;

	glEnable(GL_TEXTURE_2D);
	mui_drawable_t * dr = &ui->pixels.mii;
	glBindTexture(GL_TEXTURE_2D, dr->texture.id);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	// disable the repeat of textures
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	dr->texture.kind = GL_RGBA;
	glTexImage2D(GL_TEXTURE_2D, 0, 4,
			MII_VRAM_WIDTH,
			MII_VRAM_HEIGHT, 0, dr->texture.kind,	// note RGBA here, it's quicker!!
	        GL_UNSIGNED_BYTE,	// GL_UNSIGNED_INT_8_8_8_8_REV
	        mii->video.pixels);

	// bind the mui texture using the GL_ARB_texture_rectangle as well
	dr = &ui->pixels.mui;
	glBindTexture(GL_TEXTURE_2D, dr->texture.id);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

	dr->texture.kind = GL_BGRA;
	glTexImage2D(GL_TEXTURE_2D, 0, 4,
			dr->pix.row_bytes / 4,	// already power of two.
			dr->texture.size.y, 0, dr->texture.kind,
			GL_UNSIGNED_INT_8_8_8_8_REV,
			dr->pix.pixels);

	mii_floppy_t * floppy[2] = {};
	for (int i = 0; i < 7; i++) {
		if (mii_slot_command(mii, i, MII_SLOT_D2_GET_FLOPPY, floppy) == 0)
			break;
	}
	if (floppy[0]) {
		for (int fi = 0; fi < 2; fi++) {
			mii_floppy_t * f = floppy[fi];
			ui->floppy[fi].floppy = f;

			dr = &ui->pixels.floppy[fi].bits;
			// the init() call clears the structure, keep our id around
			unsigned int tex = dr->texture.id;
			mui_drawable_init(dr,
					C2_PT(MII_FLOPPY_DEFAULT_TRACK_SIZE, MII_FLOPPY_TRACK_COUNT),
					8, floppy[fi]->track_data, MII_FLOPPY_DEFAULT_TRACK_SIZE);
			dr->texture.id = tex;
			_prep_grayscale_texture(dr);
			if (!f->heat)
				f->heat = calloc(1, sizeof(*f->heat));
			dr = &ui->pixels.floppy[fi].hm_read;
			tex = dr->texture.id;
			mui_drawable_init(dr,
					C2_PT(MII_FLOPPY_HM_TRACK_SIZE, MII_FLOPPY_TRACK_COUNT),
					8, f->heat->read.map, MII_FLOPPY_HM_TRACK_SIZE);
			dr->texture.id = tex;
			_prep_grayscale_texture(dr);
			dr = &ui->pixels.floppy[fi].hm_write;
			tex = dr->texture.id;
			mui_drawable_init(dr,
					C2_PT(MII_FLOPPY_HM_TRACK_SIZE, MII_FLOPPY_TRACK_COUNT),
					8, f->heat->write.map, MII_FLOPPY_HM_TRACK_SIZE);
			dr->texture.id = tex;
			_prep_grayscale_texture(dr);
			mii_gl_make_floppy(&ui->floppy[fi].vtx, 1.0, true, true);
		}
	} else {
		printf("%s No floppy found\n", __func__);
		for (int fi = 0; fi < 2; fi++) {
			ui->floppy[fi].floppy = NULL;
			mui_drawable_clear(&ui->pixels.floppy[fi].bits);
			mui_drawable_clear(&ui->pixels.floppy[fi].hm_read);
			mui_drawable_clear(&ui->pixels.floppy[fi].hm_write);
			mii_gl_make_floppy(&ui->floppy[fi].vtx, 1.0, true, true);
		}
	}
	GLenum err = glGetError();
	if (err != GL_NO_ERROR) {
		printf("%s Error creating texture: %d\n", __func__, err);
	}
}


static void
_mii_decay_heatmap_one(
		mii_track_heatmap_t *hm)
{
	uint32_t count = 0;
	const int decay = 4;
#ifdef __SSE2__
	const int size = (MII_FLOPPY_TRACK_COUNT * MII_FLOPPY_HM_TRACK_SIZE) / 16;
	__m128i * hmw = (__m128i*)&hm->map[0];
	const __m128i s = _mm_set1_epi8(decay);
	for (int i = 0; i < size; i++) {
		__m128i b = _mm_load_si128(hmw + i);
		__m128i c = _mm_subs_epu8(b, s);
		hmw[i] = c;
		count += _mm_movemask_epi8(_mm_cmpgt_epi8(c, _mm_setzero_si128()));
	}
#else
	const int size = MII_FLOPPY_TRACK_COUNT * MII_FLOPPY_HM_TRACK_SIZE;
	uint8_t * hmb = (uint8_t*)&hm->map[0];
	for (int i = 0; i < size; i++) {
		uint8_t b = hmb[i];
		b = b > decay ? b - decay : 0;
		hmb[i] = b;
		count += !!b;
	}
#endif
	hm->cleared = count == 0;
}

static void
_mii_decay_heatmap(
		mii_floppy_heatmap_t *h)
{
	if (h->read.seed != h->read.tex || !h->read.cleared) {
		h->read.tex = h->read.tex;
		_mii_decay_heatmap_one(&h->read);
	}
	if (h->write.seed != h->write.tex || !h->write.cleared) {
		h->write.tex = h->write.tex;
		_mii_decay_heatmap_one(&h->write);
	}
}


bool
mii_mui_gl_run(
		mii_mui_t *ui)
{
	mii_t * mii = &ui->mii;
	mui_t * mui = &ui->mui;

	mui_run(mui);
	bool draw = false;
	if (pixman_region32_not_empty(&mui->inval)) {
		draw = true;
		mui_drawable_t * dr = &ui->pixels.mui;
		mui_draw(mui, dr, 0);
		glBindTexture(GL_TEXTURE_2D, dr->texture.id);

		pixman_region32_intersect_rect(&mui->redraw, &mui->redraw,
				0, 0, dr->pix.size.x, dr->pix.size.y);
		int rc = 0;
		c2_rect_t *ra = (c2_rect_t*)pixman_region32_rectangles(&mui->redraw, &rc);
	//	rc = 1; ra = &C2_RECT(0, 0, mui->screen_size.x, mui->screen_size.y);
		if (rc) {
	//		printf("GL: %d rects to redraw\n", rc);
			for (int i = 0; i < rc; i++) {
				c2_rect_t r = ra[i];
	//			printf("GL: %d,%d %dx%d\n", r.l, r.t, c2_rect_width(&r), c2_rect_height(&r));
				glPixelStorei(GL_UNPACK_ROW_LENGTH, dr->pix.row_bytes / 4);
				glTexSubImage2D(GL_TEXTURE_2D, 0, r.l, r.t,
						c2_rect_width(&r), c2_rect_height(&r),
						dr->texture.kind,
						GL_UNSIGNED_INT_8_8_8_8_REV,
						dr->pix.pixels + (r.t * dr->pix.row_bytes) + (r.l * 4));
			}
		}
		glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
		pixman_region32_clear(&mui->redraw);
	}
	uint32_t current_frame = mii->video.frame_count;
	if (current_frame != mii->video.frame_drawn) {
	//	miigl_counter_tick(&ui->videoc, miigl_get_time());
		draw = true;
		mii->video.frame_drawn = current_frame;
		// update the whole texture
		mui_drawable_t * dr = &ui->pixels.mii;
		glBindTexture(GL_TEXTURE_2D, dr->texture.id);
		glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0,
				MII_VRAM_WIDTH,
				MII_VIDEO_HEIGHT, dr->texture.kind,
				GL_UNSIGNED_INT_8_8_8_8_REV,
				mii->video.pixels);
	}
	for (int fi = 0; fi < 2; fi++) {
		if (!ui->floppy[fi].floppy)
			continue;
		mui_drawable_t * dr = NULL;
		mii_floppy_t * f = ui->floppy[fi].floppy;
		if (ui->floppy[fi].seed_load != f->seed_dirty) {
			draw = true;
			ui->floppy[fi].seed_load = f->seed_dirty;
		//	printf("Floppy %d: Reloading texture\n", fi);
			dr = &ui->pixels.floppy[fi].bits;
			int bc = (f->tracks[0].bit_count + 7) / 8;
			int max = MII_FLOPPY_DEFAULT_TRACK_SIZE;
			ui->floppy[fi].max_width = (double)bc / (double)max;
			glBindTexture(GL_TEXTURE_2D, dr->texture.id);
			glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0,
					dr->pix.row_bytes, dr->pix.size.y,
					dr->texture.kind, GL_UNSIGNED_BYTE,
					f->track_data);
			// dont recalculate the vertices, just the texture coordinates
			mii_gl_make_floppy(&ui->floppy[fi].vtx,
							ui->floppy[fi].max_width, false, true);
		}
		int rm = f->heat->read.tex != f->heat->read.seed ||
						!f->heat->read.cleared;
		int wm = f->heat->write.tex != f->heat->write.seed ||
						!f->heat->write.cleared;
		// don't decay if we're not running
		if (ui->mii.state == MII_RUNNING)
			_mii_decay_heatmap(f->heat);
		if (rm) {
			glPixelStorei(GL_UNPACK_ROW_LENGTH, MII_FLOPPY_HM_TRACK_SIZE);
			dr = &ui->pixels.floppy[fi].hm_read;
			glBindTexture(GL_TEXTURE_2D, dr->texture.id);
			glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0,
					dr->pix.row_bytes, dr->pix.size.y,
					dr->texture.kind, GL_UNSIGNED_BYTE,
					f->heat->read.map);
		}
		if (wm) {
			glPixelStorei(GL_UNPACK_ROW_LENGTH, MII_FLOPPY_HM_TRACK_SIZE);
			dr = &ui->pixels.floppy[fi].hm_write;
			glBindTexture(GL_TEXTURE_2D, dr->texture.id);
			glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0,
					dr->pix.row_bytes, dr->pix.size.y,
					dr->texture.kind, GL_UNSIGNED_BYTE,
					f->heat->write.map);
		}
		glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
	}
	return draw;
}

void
mii_mui_gl_render(
		mii_mui_t *ui)
{
	glClearColor(
		.6f * ui->mui_alpha,
		.6f * ui->mui_alpha,
		.6f * ui->mui_alpha,
		1.0f);
	glClear(GL_COLOR_BUFFER_BIT);
	glPushAttrib(GL_ENABLE_BIT|GL_COLOR_BUFFER_BIT|GL_TRANSFORM_BIT);
	glDisable(GL_CULL_FACE);
	glDisable(GL_DEPTH_TEST);
	glDisable(GL_SCISSOR_TEST);
	glEnable(GL_BLEND);
	glEnable(GL_TEXTURE_2D);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

	/* setup viewport/project */
	glViewport(0, 0,
				(GLsizei)ui->window_size.x,
				(GLsizei)ui->window_size.y);
	glMatrixMode(GL_PROJECTION);
	glPushMatrix();
	glLoadIdentity();
	glOrtho(0.0f, ui->window_size.x, ui->window_size.y,
				0.0f, -1.0f, 1.0f);
	glMatrixMode(GL_MODELVIEW);
	glPushMatrix();
	glLoadIdentity();
	// This (was) the recommended way to handle pixel alignment in glOrtho
	// mode, but this seems to have changed -- now it looks like Linear filtering
//	glTranslatef(0.375f, 0.375f, 0.0f);
	{
		/* draw mii texture */
		glColor3f(1.0f, 1.0f, 1.0f);
		mui_drawable_t * dr = &ui->pixels.mii;
		glEnable(GL_TEXTURE_2D);
		glBindTexture(GL_TEXTURE_2D, dr->texture.id);
		glBegin(GL_QUADS);
		c2_rect_t r = ui->video_frame;
		glTexCoord2f(0, 0);
				glVertex2f(r.l, r.t);
		glTexCoord2f(MII_VIDEO_WIDTH / (double)MII_VRAM_WIDTH, 0);
				glVertex2f(r.r, r.t);
		glTexCoord2f(MII_VIDEO_WIDTH / (double)MII_VRAM_WIDTH,
					MII_VIDEO_HEIGHT / (double)MII_VRAM_HEIGHT);
				glVertex2f(r.r, r.b);
		glTexCoord2f(0,
					MII_VIDEO_HEIGHT / (double)MII_VRAM_HEIGHT);
				glVertex2f(r.l, r.b);
		glEnd();

		/* draw floppy textures, floppy 0 is left of the screen,
		   floppy 1 is right */
		for (int i = 0; i < 2; i++) {
			dr = &ui->pixels.floppy[i].bits;
			mii_floppy_t *f = ui->floppy[i].floppy;
			if (!f || !dr->pix.pixels)
				continue;
			if (ui->mii.state == MII_RUNNING) {
				if (f->motor) {
					if (dr->texture.opacity < 1.0f)
						dr->texture.opacity += 0.10f;
					if (dr->texture.opacity > 1.0f)
						dr->texture.opacity = 1.0f;
				} else  {
					if (dr->texture.opacity > 0.0f)
						dr->texture.opacity -= 0.01f;
					if (dr->texture.opacity < 0.0f)
						dr->texture.opacity = 0.0f;
				}
			}
			float main_opacity = dr->texture.opacity;
			if (main_opacity <= 0.0f)
				continue;
			const float angle_offset = 60;	// head angle offset on display
			if (1) {
				glPushMatrix();
				// make floppy slide in/out with opacity
				glTranslatef(-10 - (100.0 * ( 1.0f - main_opacity) ),
						200 + (i * 350), 0);
				glScalef(15, 15, 1);
				{
					glColor4f(0.0f, 0.0f, 0.0f, main_opacity);
					glDisable(GL_TEXTURE_2D);
					glEnableClientState(GL_VERTEX_ARRAY);
					glVertexPointer(2, GL_FLOAT, 0, ui->floppy_base.e);
					int element_count = ui->floppy_base.count / 2;
					glDrawArrays(GL_TRIANGLES, 0, element_count);
				}
				int track_id = f->track_id[f->qtrack];
				double bc = (double)f->bit_position /
						(double)f->tracks[track_id].bit_count;
				bc = 360 - (bc * 360.0);
				bc += angle_offset;
				if (bc >= 360.0)
					bc -= 360.0;
				glRotatef(bc, 0, 0, 1);
				dr = &ui->pixels.floppy[i].bits;
				glEnable(GL_TEXTURE_2D);
				glBindTexture(GL_TEXTURE_2D, dr->texture.id);
//				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
//				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
				glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
				glColor4f(1.0f, 1.0f, 1.0f, main_opacity);
				glEnableClientState(GL_VERTEX_ARRAY);
				glEnableClientState(GL_TEXTURE_COORD_ARRAY);
				glVertexPointer(2, GL_FLOAT, 0, ui->floppy[i].vtx.pos.e);
				glTexCoordPointer(2, GL_FLOAT, 0, ui->floppy[i].vtx.tex.e);
				int element_count = ui->floppy[i].vtx.pos.count / 2;
				glDrawArrays(ui->floppy[i].vtx.kind, 0, element_count);
				// draw heatmap and head with full opacity
				// otherwise we get wierd artifacts
				if (f->heat) {
					glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_COLOR);
					dr = &ui->pixels.floppy[i].hm_read;
					glColor4f(0.0f, 1.0f, 0.0f, 1.0);
					glBindTexture(GL_TEXTURE_2D, dr->texture.id);
					glDrawArrays(ui->floppy[i].vtx.kind, 0, element_count);
					dr = &ui->pixels.floppy[i].hm_write;
					glColor4f(1.0f, 0.0f, 0.0f, 1.0);
					glBindTexture(GL_TEXTURE_2D, dr->texture.id);
					glDrawArrays(ui->floppy[i].vtx.kind, 0, element_count);
				}
				glDisableClientState(GL_VERTEX_ARRAY);
				glDisableClientState(GL_TEXTURE_COORD_ARRAY);
				if (main_opacity > 0.8f) {
					// Draw head small rectangle
					dr = &ui->pixels.floppy[i].bits;
					track_id = f->qtrack / 4;
					glDisable(GL_TEXTURE_2D);
					glRotatef(-bc + angle_offset, 0, 0, 1);
					glTranslatef(MII_GL_FLOPPY_FLUX_RADIUS_IN +
								(((35 - track_id) / 35.0) *
								(MII_GL_FLOPPY_FLUX_RADIUS_OUT-
								MII_GL_FLOPPY_FLUX_RADIUS_IN)), 0, 0);
					const float r = 0.3;
					glColor4f(1.0f, 0.0f, 0.0f, main_opacity);
					glBegin(GL_QUADS);
					glVertex2f(-r, -r); glVertex2f(-r, r);
					glVertex2f(r, r); glVertex2f(r, -r);
					glEnd();
				}
				glPopMatrix();
			}
		}
		/* draw mui texture */
		if (ui->mui_alpha > 0.0f) {
			glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
			glColor4f(1.0f, 1.0f, 1.0f, ui->mui_alpha);
			dr = &ui->pixels.mui;
			glEnable(GL_TEXTURE_2D);
			glBindTexture(GL_TEXTURE_2D, dr->texture.id);
			glBegin(GL_QUADS);
			glTexCoord2f(0, 0); glVertex2f(0, 0);
			glTexCoord2f(
					ui->window_size.x / (double)(dr->pix.row_bytes / 4), 0);
					glVertex2f(ui->window_size.x, 0);
			glTexCoord2f(ui->window_size.x / (double)(dr->pix.row_bytes / 4),
						ui->window_size.y / (double)(dr->texture.size.y));
					glVertex2f(ui->window_size.x, ui->window_size.y);
			glTexCoord2f(0,
						ui->window_size.y / (double)(dr->texture.size.y));
					glVertex2f(0, ui->window_size.y);
			glEnd();
		}
	}
	glDisable(GL_CULL_FACE);
	glDisable(GL_DEPTH_TEST);
	glDisable(GL_SCISSOR_TEST);
	glDisable(GL_BLEND);
	glDisable(GL_TEXTURE_2D);

	glBindTexture(GL_TEXTURE_2D, 0);
	glMatrixMode(GL_MODELVIEW);
	glPopMatrix();
	glMatrixMode(GL_PROJECTION);
	glPopMatrix();
	glPopAttrib();
}