/*

 * Copyright (c) 2007, 2012, 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 <string.h>

#include "sun_java2d_SunGraphics2D.h"

#include "OGLPaints.h"

#include "OGLVertexCache.h"

typedef struct _J2DVertex {

    jfloat tx, ty;

    jubyte r, g, b, a;

    jfloat dx, dy;

} J2DVertex;

static J2DVertex *vertexCache = NULL;

static jint vertexCacheIndex = 0;

static GLuint maskCacheTexID = 0;

static jint maskCacheIndex = 0;

#define OGLVC_ADD_VERTEX(TX, TY, R, G, B, A, DX, DY) \

    do { \

        J2DVertex *v = &vertexCache[vertexCacheIndex++]; \

        v->tx = TX; \

        v->ty = TY; \

        v->r  = R;  \

        v->g  = G;  \

        v->b  = B;  \

        v->a  = A;  \

        v->dx = DX; \

        v->dy = DY; \

    } while (0)

#define OGLVC_ADD_QUAD(TX1, TY1, TX2, TY2, DX1, DY1, DX2, DY2, R, G, B, A) \

    do { \

        OGLVC_ADD_VERTEX(TX1, TY1, R, G, B, A, DX1, DY1); \

        OGLVC_ADD_VERTEX(TX2, TY1, R, G, B, A, DX2, DY1); \

        OGLVC_ADD_VERTEX(TX2, TY2, R, G, B, A, DX2, DY2); \

        OGLVC_ADD_VERTEX(TX1, TY2, R, G, B, A, DX1, DY2); \

    } while (0)

jboolean

OGLVertexCache_InitVertexCache(OGLContext *oglc)

{

    J2dTraceLn(J2D_TRACE_INFO, "OGLVertexCache_InitVertexCache");

    if (vertexCache == NULL) {

        vertexCache = (J2DVertex *)malloc(OGLVC_MAX_INDEX * sizeof(J2DVertex));

        if (vertexCache == NULL) {

            return JNI_FALSE;

        }

    }

    if (!oglc->vertexCacheEnabled) {

        j2d_glTexCoordPointer(2, GL_FLOAT,

                              sizeof(J2DVertex), vertexCache);

        j2d_glColorPointer(4, GL_UNSIGNED_BYTE,

                           sizeof(J2DVertex), ((jfloat *)vertexCache) + 2);

        j2d_glVertexPointer(2, GL_FLOAT,

                            sizeof(J2DVertex), ((jfloat *)vertexCache) + 3);

        j2d_glEnableClientState(GL_TEXTURE_COORD_ARRAY);

        j2d_glEnableClientState(GL_COLOR_ARRAY);

        j2d_glEnableClientState(GL_VERTEX_ARRAY);

        oglc->vertexCacheEnabled = JNI_TRUE;

    }

    return JNI_TRUE;

}

void

OGLVertexCache_FlushVertexCache()

{

    J2dTraceLn(J2D_TRACE_INFO, "OGLVertexCache_FlushVertexCache");

    if (vertexCacheIndex > 0) {

        j2d_glDrawArrays(GL_QUADS, 0, vertexCacheIndex);

    }

    vertexCacheIndex = 0;

}

/**

 * This method is somewhat hacky, but necessary for the foreseeable future.

 * The problem is the way OpenGL handles color values in vertex arrays.  When

 * a vertex in a vertex array contains a color, and then the vertex array

 * is rendered via glDrawArrays(), the global OpenGL color state is actually

 * modified each time a vertex is rendered.  This means that after all

 * vertices have been flushed, the global OpenGL color state will be set to

 * the color of the most recently rendered element in the vertex array.

 *

 * The reason this is a problem for us is that we do not want to flush the

 * vertex array (in the case of mask/glyph operations) or issue a glEnd()

 * (in the case of non-antialiased primitives) everytime the current color

 * changes, which would defeat any benefit from batching in the first place.

 * We handle this in practice by not calling CHECK/RESET_PREVIOUS_OP() when

 * the simple color state is changing in OGLPaints_SetColor().  This is

 * problematic for vertex caching because we may end up with the following

 * situation, for example:

 *   SET_COLOR (orange)

 *   MASK_FILL

 *   MASK_FILL

 *   SET_COLOR (blue; remember, this won't cause a flush)

 *   FILL_RECT (this will cause the vertex array to be flushed)

 *

 * In this case, we would actually end up rendering an orange FILL_RECT,

 * not a blue one as intended, because flushing the vertex cache flush would

 * override the color state from the most recent SET_COLOR call.

 *

 * Long story short, the easiest way to resolve this problem is to call

 * this method just after disabling the mask/glyph cache, which will ensure

 * that the appropriate color state is restored.

 */

void

OGLVertexCache_RestoreColorState(OGLContext *oglc)

{

    if (oglc->paintState == sun_java2d_SunGraphics2D_PAINT_ALPHACOLOR) {

        OGLPaints_SetColor(oglc, oglc->pixel);

    }

}

static jboolean

OGLVertexCache_InitMaskCache()

{

    J2dTraceLn(J2D_TRACE_INFO, "OGLVertexCache_InitMaskCache");

    maskCacheTexID =

        OGLContext_CreateBlitTexture(GL_INTENSITY8, GL_LUMINANCE,

                                     OGLVC_MASK_CACHE_WIDTH_IN_TEXELS,

                                     OGLVC_MASK_CACHE_HEIGHT_IN_TEXELS);

    // init special fully opaque tile in the upper-right corner of

    // the mask cache texture

    {

        GLubyte allOnes[OGLVC_MASK_CACHE_TILE_SIZE];

        memset(allOnes, 0xff, OGLVC_MASK_CACHE_TILE_SIZE);

        j2d_glTexSubImage2D(GL_TEXTURE_2D, 0,

                            OGLVC_MASK_CACHE_SPECIAL_TILE_X,

                            OGLVC_MASK_CACHE_SPECIAL_TILE_Y,

                            OGLVC_MASK_CACHE_TILE_WIDTH,

                            OGLVC_MASK_CACHE_TILE_HEIGHT,

                            GL_LUMINANCE, GL_UNSIGNED_BYTE, allOnes);

    }

    return JNI_TRUE;

}

void

OGLVertexCache_EnableMaskCache(OGLContext *oglc)

{

    J2dTraceLn(J2D_TRACE_INFO, "OGLVertexCache_EnableMaskCache");

    if (!OGLVertexCache_InitVertexCache(oglc)) {

        return;

    }

    if (maskCacheTexID == 0) {

        if (!OGLVertexCache_InitMaskCache()) {

            return;

        }

    }

    j2d_glEnable(GL_TEXTURE_2D);

    j2d_glBindTexture(GL_TEXTURE_2D, maskCacheTexID);

    OGLC_UPDATE_TEXTURE_FUNCTION(oglc, GL_MODULATE);

    j2d_glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

}

void

OGLVertexCache_DisableMaskCache(OGLContext *oglc)

{

    J2dTraceLn(J2D_TRACE_INFO, "OGLVertexCache_DisableMaskCache");

    OGLVertexCache_FlushVertexCache();

    OGLVertexCache_RestoreColorState(oglc);

    j2d_glDisable(GL_TEXTURE_2D);

    j2d_glPixelStorei(GL_UNPACK_ALIGNMENT, 4);

    j2d_glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);

    j2d_glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);

    j2d_glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);

    maskCacheIndex = 0;

}

void

OGLVertexCache_AddMaskQuad(OGLContext *oglc,

                           jint srcx, jint srcy,

                           jint dstx, jint dsty,

                           jint width, jint height,

                           jint maskscan, void *mask)

{

    jfloat tx1, ty1, tx2, ty2;

    jfloat dx1, dy1, dx2, dy2;

    J2dTraceLn1(J2D_TRACE_INFO, "OGLVertexCache_AddMaskQuad: %d",

                maskCacheIndex);

    if (maskCacheIndex >= OGLVC_MASK_CACHE_MAX_INDEX ||

        vertexCacheIndex >= OGLVC_MAX_INDEX)

    {

        OGLVertexCache_FlushVertexCache();

        maskCacheIndex = 0;

    }

    if (mask != NULL) {

        jint texx = OGLVC_MASK_CACHE_TILE_WIDTH *

            (maskCacheIndex % OGLVC_MASK_CACHE_WIDTH_IN_TILES);

        jint texy = OGLVC_MASK_CACHE_TILE_HEIGHT *

            (maskCacheIndex / OGLVC_MASK_CACHE_WIDTH_IN_TILES);

        // update the source pointer offsets

        j2d_glPixelStorei(GL_UNPACK_SKIP_PIXELS, srcx);

        j2d_glPixelStorei(GL_UNPACK_SKIP_ROWS, srcy);

        j2d_glPixelStorei(GL_UNPACK_ROW_LENGTH, maskscan);

        // copy alpha mask into texture tile

        j2d_glTexSubImage2D(GL_TEXTURE_2D, 0,

                            texx, texy, width, height,

                            GL_LUMINANCE, GL_UNSIGNED_BYTE, mask);

        tx1 = ((jfloat)texx) / OGLVC_MASK_CACHE_WIDTH_IN_TEXELS;

        ty1 = ((jfloat)texy) / OGLVC_MASK_CACHE_HEIGHT_IN_TEXELS;

        maskCacheIndex++;

    } else {

        // use special fully opaque tile

        tx1 = ((jfloat)OGLVC_MASK_CACHE_SPECIAL_TILE_X) /

            OGLVC_MASK_CACHE_WIDTH_IN_TEXELS;

        ty1 = ((jfloat)OGLVC_MASK_CACHE_SPECIAL_TILE_Y) /

            OGLVC_MASK_CACHE_HEIGHT_IN_TEXELS;

    }

    tx2 = tx1 + (((jfloat)width) / OGLVC_MASK_CACHE_WIDTH_IN_TEXELS);

    ty2 = ty1 + (((jfloat)height) / OGLVC_MASK_CACHE_HEIGHT_IN_TEXELS);

    dx1 = (jfloat)dstx;

    dy1 = (jfloat)dsty;

    dx2 = dx1 + width;

    dy2 = dy1 + height;

    OGLVC_ADD_QUAD(tx1, ty1, tx2, ty2,

                   dx1, dy1, dx2, dy2,

                   oglc->r, oglc->g, oglc->b, oglc->a);

}

void

OGLVertexCache_AddGlyphQuad(OGLContext *oglc,

                            jfloat tx1, jfloat ty1, jfloat tx2, jfloat ty2,

                            jfloat dx1, jfloat dy1, jfloat dx2, jfloat dy2)

{

    J2dTraceLn(J2D_TRACE_INFO, "OGLVertexCache_AddGlyphQuad");

    if (vertexCacheIndex >= OGLVC_MAX_INDEX) {

        OGLVertexCache_FlushVertexCache();

    }

    OGLVC_ADD_QUAD(tx1, ty1, tx2, ty2,

                   dx1, dy1, dx2, dy2,

                   oglc->r, oglc->g, oglc->b, oglc->a);

}

#endif /* !HEADLESS */