/*

 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

#ifndef HEADLESS

#include <stdlib.h>

#include <limits.h>

#include <math.h>

#include <jlong.h>

#include "sun_java2d_metal_MTLTextRenderer.h"

#include "SurfaceData.h"

#include "MTLContext.h"

#include "MTLRenderQueue.h"

#include "MTLTextRenderer.h"

#include "MTLVertexCache.h"

#include "AccelGlyphCache.h"

/**

 * The following constants define the inner and outer bounds of the

 * accelerated glyph cache.

 */

#define MTLTR_CACHE_WIDTH       1024

#define MTLTR_CACHE_HEIGHT      1024

#define MTLTR_CACHE_CELL_WIDTH  32

#define MTLTR_CACHE_CELL_HEIGHT 32

/**

 * The current "glyph mode" state.  This variable is used to track the

 * codepath used to render a particular glyph.  This variable is reset to

 * MODE_NOT_INITED at the beginning of every call to MTLTR_DrawGlyphList().

 * As each glyph is rendered, the glyphMode variable is updated to reflect

 * the current mode, so if the current mode is the same as the mode used

 * to render the previous glyph, we can avoid doing costly setup operations

 * each time.

 */

typedef enum {

    MODE_NOT_INITED,

    MODE_USE_CACHE_GRAY,

    MODE_USE_CACHE_LCD,

    MODE_NO_CACHE_GRAY,

    MODE_NO_CACHE_LCD,

    MODE_NO_CACHE_COLOR

} GlyphMode;

static GlyphMode glyphMode = MODE_NOT_INITED;

/**

 * There are two separate glyph caches: for AA and for LCD.

 * Once one of them is initialized as either GRAY or LCD, it

 * stays in that mode for the duration of the application.  It should

 * be safe to use this one glyph cache for all screens in a multimon

 * environment, since the glyph cache texture is shared between all contexts,

 * and (in theory) OpenGL drivers should be smart enough to manage that

 * texture across all screens.

 */

static GlyphCacheInfo *glyphCacheLCD = NULL;

static GlyphCacheInfo *glyphCacheAA = NULL;

/**

 * The handle to the LCD text fragment program object.

 */

static GLhandleARB lcdTextProgram = 0;

/**

 * This value tracks the previous LCD contrast setting, so if the contrast

 * value hasn't changed since the last time the gamma uniforms were

 * updated (not very common), then we can skip updating the unforms.

 */

static jint lastLCDContrast = -1;

/**

 * This value tracks the previous LCD rgbOrder setting, so if the rgbOrder

 * value has changed since the last time, it indicates that we need to

 * invalidate the cache, which may already store glyph images in the reverse

 * order.  Note that in most real world applications this value will not

 * change over the course of the application, but tests like Font2DTest

 * allow for changing the ordering at runtime, so we need to handle that case.

 */

static jboolean lastRGBOrder = JNI_TRUE;

/**

 * This constant defines the size of the tile to use in the

 * MTLTR_DrawLCDGlyphNoCache() method.  See below for more on why we

 * restrict this value to a particular size.

 */

#define MTLTR_NOCACHE_TILE_SIZE 32

/**

 * These constants define the size of the "cached destination" texture.

 * This texture is only used when rendering LCD-optimized text, as that

 * codepath needs direct access to the destination.  There is no way to

 * access the framebuffer directly from an OpenGL shader, so we need to first

 * copy the destination region corresponding to a particular glyph into

 * this cached texture, and then that texture will be accessed inside the

 * shader.  Copying the destination into this cached texture can be a very

 * expensive operation (accounting for about half the rendering time for

 * LCD text), so to mitigate this cost we try to bulk read a horizontal

 * region of the destination at a time.  (These values are empirically

 * derived for the common case where text runs horizontally.)

 *

 * Note: It is assumed in various calculations below that:

 *     (MTLTR_CACHED_DEST_WIDTH  >= MTLTR_CACHE_CELL_WIDTH)  &&

 *     (MTLTR_CACHED_DEST_WIDTH  >= MTLTR_NOCACHE_TILE_SIZE) &&

 *     (MTLTR_CACHED_DEST_HEIGHT >= MTLTR_CACHE_CELL_HEIGHT) &&

 *     (MTLTR_CACHED_DEST_HEIGHT >= MTLTR_NOCACHE_TILE_SIZE)

 */

#define MTLTR_CACHED_DEST_WIDTH  1024

#define MTLTR_CACHED_DEST_HEIGHT (MTLTR_CACHE_CELL_HEIGHT * 2)

/**

 * The handle to the "cached destination" texture object.

 */

static GLuint cachedDestTextureID = 0;

/**

 * The current bounds of the "cached destination" texture, in destination

 * coordinate space.  The width/height of these bounds will not exceed the

 * MTLTR_CACHED_DEST_WIDTH/HEIGHT values defined above.  These bounds are

 * only considered valid when the isCachedDestValid flag is JNI_TRUE.

 */

static SurfaceDataBounds cachedDestBounds;

/**

 * This flag indicates whether the "cached destination" texture contains

 * valid data.  This flag is reset to JNI_FALSE at the beginning of every

 * call to MTLTR_DrawGlyphList().  Once we copy valid destination data

 * into the cached texture, this flag is set to JNI_TRUE.  This way, we can

 * limit the number of times we need to copy destination data, which is a

 * very costly operation.

 */

static jboolean isCachedDestValid = JNI_FALSE;

/**

 * The bounds of the previously rendered LCD glyph, in destination

 * coordinate space.  We use these bounds to determine whether the glyph

 * currently being rendered overlaps the previously rendered glyph (i.e.

 * its bounding box intersects that of the previously rendered glyph).  If

 * so, we need to re-read the destination area associated with that previous

 * glyph so that we can correctly blend with the actual destination data.

 */

static SurfaceDataBounds previousGlyphBounds;

/**

 * Initializes the one glyph cache (texture and data structure).

 * If lcdCache is JNI_TRUE, the texture will contain RGB data,

 * otherwise we will simply store the grayscale/monochrome glyph images

 * as intensity values (which work well with the GL_MODULATE function).

 */

static jboolean

MTLTR_InitGlyphCache(jboolean lcdCache)

{

    //TODO

    return JNI_TRUE;

}

/**

 * Adds the given glyph to the glyph cache (texture and data structure)

 * associated with the given MTLContext.

 */

static void

MTLTR_AddTmTLyphCache(GlyphInfo *glyph, GLenum pixelFormat)

{

    //TODO

    CacheCellInfo *ccinfo;

    GlyphCacheInfo *gcinfo;

    J2dTraceLn(J2D_TRACE_INFO, "MTLTR_AddTmTLyphCache");

    //J2dTracePrimitive("MTLTR_InitGlyphCache");

}

/**

 * (Re)Initializes the gamma related uniforms.

 *

 * The given contrast value is an int in the range [100, 250] which we will

 * then scale to fit in the range [1.0, 2.5].

 */

static jboolean

MTLTR_UpdateLCDTextContrast(jint contrast)

{

    //TODO

    return JNI_TRUE;

}

/**

 * Updates the current gamma-adjusted source color ("src_adj") of the LCD

 * text shader program.  Note that we could calculate this value in the

 * shader (e.g. just as we do for "dst_adj"), but would be unnecessary work

 * (and a measurable performance hit, maybe around 5%) since this value is

 * constant over the entire glyph list.  So instead we just calculate the

 * gamma-adjusted value once and update the uniform parameter of the LCD

 * shader as needed.

 */

static jboolean

MTLTR_UpdateLCDTextColor(jint contrast)

{

    //TODO

    return JNI_TRUE;

}

/**

 * Enables the LCD text shader and updates any related state, such as the

 * gamma lookup table textures.

 */

static jboolean

MTLTR_EnableLCDGlyphModeState(GLuint glyphTextureID,

                              GLuint dstTextureID,

                              jint contrast)

{

    //TODO

    return JNI_TRUE;

}

void

MTLTR_EnableGlyphVertexCache(MTLContext *mtlc)

{

    //TODO

}

void

MTLTR_DisableGlyphVertexCache(MTLContext *mtlc)

{

    //TODO

    J2dTraceLn(J2D_TRACE_INFO, "MTLTR_DisableGlyphVertexCache");

}

/**

 * Disables any pending state associated with the current "glyph mode".

 */

void

MTLTR_DisableGlyphModeState()

{

    //TODO

    J2dTraceLn1(J2D_TRACE_VERBOSE,

                "MTLTR_DisableGlyphModeState: mode=%d", glyphMode);

}

static jboolean

MTLTR_DrawGrayscaleGlyphViaCache(MTLContext *mtlc,

                                 GlyphInfo *ginfo, jint x, jint y)

{

    //TODO

    return JNI_TRUE;

}

/**

 * Evaluates to true if the rectangle defined by gx1/gy1/gx2/gy2 is

 * inside outerBounds.

 */

#define INSIDE(gx1, gy1, gx2, gy2, outerBounds) \

    (((gx1) >= outerBounds.x1) && ((gy1) >= outerBounds.y1) && \

     ((gx2) <= outerBounds.x2) && ((gy2) <= outerBounds.y2))

/**

 * Evaluates to true if the rectangle defined by gx1/gy1/gx2/gy2 intersects

 * the rectangle defined by bounds.

 */

#define INTERSECTS(gx1, gy1, gx2, gy2, bounds) \

    ((bounds.x2 > (gx1)) && (bounds.y2 > (gy1)) && \

     (bounds.x1 < (gx2)) && (bounds.y1 < (gy2)))

/**

 * This method checks to see if the given LCD glyph bounds fall within the

 * cached destination texture bounds.  If so, this method can return

 * immediately.  If not, this method will copy a chunk of framebuffer data

 * into the cached destination texture and then update the current cached

 * destination bounds before returning.

 */

static void

MTLTR_UpdateCachedDestination(MTLSDOps *dstOps, GlyphInfo *ginfo,

                              jint gx1, jint gy1, jint gx2, jint gy2,

                              jint glyphIndex, jint totalGlyphs)

{

    //TODO

}

static jboolean

MTLTR_DrawLCDGlyphViaCache(MTLContext *mtlc, MTLSDOps *dstOps,

                           GlyphInfo *ginfo, jint x, jint y,

                           jint glyphIndex, jint totalGlyphs,

                           jboolean rgbOrder, jint contrast,

                           jint dstTextureID, jboolean * opened)

{

    //TODO

    return JNI_TRUE;

}

static jboolean

MTLTR_DrawGrayscaleGlyphNoCache(MTLContext *mtlc,

                                GlyphInfo *ginfo, jint x, jint y, BMTLSDOps *dstOps)

{

    jfloat dx1, dy1, dx2, dy2;

    jint width = ginfo->width;

    jint height = ginfo->height;

    J2dTraceLn(J2D_TRACE_INFO, "MTLTR_DrawGrayscaleGlyphNoCache");

    /*

     * TODO : Glyph caching is not used yet we need to

     * implement it.

     */

    if (glyphMode != MODE_NO_CACHE_GRAY) {

        glyphMode = MODE_NO_CACHE_GRAY;

    }

    dx1 = (jfloat)x;

    dy1 = (jfloat)y;

    dx2 = x + width;

    dy2 = y + height;

    J2dTraceLn4(J2D_TRACE_INFO,

        "Destination coordinates dx1 = %f dy1 = %f dx2 = %f dy2 = %f", dx1, dy1, dx2, dy2);

    MTLVertexCache_AddVertexTriangles(dx1, dy1, dx2, dy2);

    return JNI_TRUE;

}

static jboolean

MTLTR_DrawLCDGlyphNoCache(MTLContext *mtlc, MTLSDOps *dstOps,

                          GlyphInfo *ginfo, jint x, jint y,

                          jint rowBytesOffset,

                          jboolean rgbOrder, jint contrast,

                          jint dstTextureID)

{

    //TODO

    return JNI_TRUE;

}

static jboolean

MTLTR_DrawColorGlyphNoCache(MTLContext *mtlc, GlyphInfo *ginfo, jint x, jint y)

{

    //TODO

    return JNI_TRUE;

}

// see DrawGlyphList.c for more on this macro...

#define FLOOR_ASSIGN(l, r) \

    if ((r)<0) (l) = ((int)floor(r)); else (l) = ((int)(r))

void

MTLTR_DrawGlyphList(JNIEnv *env, MTLContext *mtlc, BMTLSDOps *dstOps,

                    jint totalGlyphs, jboolean usePositions,

                    jboolean subPixPos, jboolean rgbOrder, jint lcdContrast,

                    jfloat glyphListOrigX, jfloat glyphListOrigY,

                    unsigned char *images, unsigned char *positions)

{

    int glyphCounter;

    J2dTraceLn(J2D_TRACE_INFO, "MTLTR_DrawGlyphList");

    RETURN_IF_NULL(mtlc);

    RETURN_IF_NULL(dstOps);

    RETURN_IF_NULL(images);

    if (usePositions) {

        RETURN_IF_NULL(positions);

    }

    glyphMode = MODE_NOT_INITED;

    isCachedDestValid = JNI_FALSE;

    J2dTraceLn1(J2D_TRACE_INFO, "totalGlyphs = %d", totalGlyphs);

    MTLVertexCache_CreateSamplingEncoder(mtlc, dstOps);

    for (glyphCounter = 0; glyphCounter < totalGlyphs; glyphCounter++) {

        J2dTraceLn(J2D_TRACE_INFO, "Entered for loop for glyph list");

        jint x, y;

        jfloat glyphx, glyphy;

        jboolean grayscale, ok;

        GlyphInfo *ginfo = (GlyphInfo *)jlong_to_ptr(NEXT_LONG(images));

        if (ginfo == NULL) {

            // this shouldn't happen, but if it does we'll just break out...

            J2dRlsTraceLn(J2D_TRACE_ERROR,

                          "MTLTR_DrawGlyphList: glyph info is null");

            break;

        }

        grayscale = (ginfo->rowBytes == ginfo->width);

        if (usePositions) {

            jfloat posx = NEXT_FLOAT(positions);

            jfloat posy = NEXT_FLOAT(positions);

            glyphx = glyphListOrigX + posx + ginfo->topLeftX;

            glyphy = glyphListOrigY + posy + ginfo->topLeftY;

            FLOOR_ASSIGN(x, glyphx);

            FLOOR_ASSIGN(y, glyphy);

        } else {

            glyphx = glyphListOrigX + ginfo->topLeftX;

            glyphy = glyphListOrigY + ginfo->topLeftY;

            FLOOR_ASSIGN(x, glyphx);

            FLOOR_ASSIGN(y, glyphy);

            glyphListOrigX += ginfo->advanceX;

            glyphListOrigY += ginfo->advanceY;

        }

        if (ginfo->image == NULL) {

            continue;

        }

        //TODO : Right now we have initial texture mapping logic

        // as we implement LCD, cache usage add new selection condition.

        if (grayscale) {

            // grayscale or monochrome glyph data

            if (ginfo->width <= MTLTR_CACHE_CELL_WIDTH &&

                ginfo->height <= MTLTR_CACHE_CELL_HEIGHT)

            {

                J2dTraceLn(J2D_TRACE_INFO, "Forced Grayscale no cache");

                //ok = MTLTR_DrawGrayscaleGlyphViaCache(oglc, ginfo, x, y);

                // TODO: Replace no cache with cache rendering

                ok = MTLTR_DrawGrayscaleGlyphNoCache(mtlc, ginfo, x, y, dstOps);

            } else {

                J2dTraceLn(J2D_TRACE_INFO, "Grayscale no cache");

                ok = MTLTR_DrawGrayscaleGlyphNoCache(mtlc, ginfo, x, y, dstOps);

            }

        } else {

            // LCD-optimized glyph data

            jint rowBytesOffset = 0;

            if (subPixPos) {

                jint frac = (jint)((glyphx - x) * 3);

                if (frac != 0) {

                    rowBytesOffset = 3 - frac;

                    x += 1;

                }

            }

            // TODO: Implement LCD text rendering

            if (rowBytesOffset == 0 &&

                ginfo->width <= MTLTR_CACHE_CELL_WIDTH &&

                ginfo->height <= MTLTR_CACHE_CELL_HEIGHT)

            {

                J2dTraceLn(J2D_TRACE_INFO, "LCD cache");

                /*ok = MTLTR_DrawLCDGlyphViaCache(oglc, dstOps,

                                                ginfo, x, y,

                                                glyphCounter, totalGlyphs,

                                                rgbOrder, lcdContrast,

                                                dstTextureID);*/

                ok = JNI_FALSE;

            } else {

                J2dTraceLn(J2D_TRACE_INFO, "LCD no cache");

                /*ok = MTLTR_DrawLCDGlyphNoCache(oglc, dstOps,

                                               ginfo, x, y,

                                               rowBytesOffset,

                                               rgbOrder, lcdContrast,

                                               dstTextureID);*/

                ok = JNI_FALSE;

            }

        }

        if (!ok) {

            break;

        }

    }

    MTLVertexCache_FlushVertexCache(mtlc);

    // TODO : Disable glyph state.

}

JNIEXPORT void JNICALL

Java_sun_java2d_metal_MTLTextRenderer_drawGlyphList

    (JNIEnv *env, jobject self,

     jint numGlyphs, jboolean usePositions,

     jboolean subPixPos, jboolean rgbOrder, jint lcdContrast,

     jfloat glyphListOrigX, jfloat glyphListOrigY,

     jlongArray imgArray, jfloatArray posArray)

{

    unsigned char *images;

    J2dTraceLn(J2D_TRACE_INFO, "MTLTextRenderer_drawGlyphList");

    images = (unsigned char *)

        (*env)->GetPrimitiveArrayCritical(env, imgArray, NULL);

    if (images != NULL) {

        MTLContext *mtlc = MTLRenderQueue_GetCurrentContext();

        BMTLSDOps *dstOps = MTLRenderQueue_GetCurrentDestination();

        if (usePositions) {

            unsigned char *positions = (unsigned char *)

                (*env)->GetPrimitiveArrayCritical(env, posArray, NULL);

            if (positions != NULL) {

                MTLTR_DrawGlyphList(env, mtlc, dstOps,

                                    numGlyphs, usePositions,

                                    subPixPos, rgbOrder, lcdContrast,

                                    glyphListOrigX, glyphListOrigY,

                                    images, positions);

                (*env)->ReleasePrimitiveArrayCritical(env, posArray,

                                                      positions, JNI_ABORT);

            }