/*

 * Copyright (c) 2003, 2008, 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 <jlong.h>

#include <jni_util.h>

#include <math.h>

#include "sun_java2d_opengl_OGLRenderer.h"

#include "OGLRenderer.h"

#include "OGLRenderQueue.h"

#include "OGLSurfaceData.h"

/**

 * Note: Some of the methods in this file apply a "magic number"

 * translation to line segments.  The OpenGL specification lays out the

 * "diamond exit rule" for line rasterization, but it is loose enough to

 * allow for a wide range of line rendering hardware.  (It appears that

 * some hardware, such as the Nvidia GeForce2 series, does not even meet

 * the spec in all cases.)  As such it is difficult to find a mapping

 * between the Java2D and OpenGL line specs that works consistently across

 * all hardware combinations.

 *

 * Therefore the "magic numbers" you see here have been empirically derived

 * after testing on a variety of graphics hardware in order to find some

 * reasonable middle ground between the two specifications.  The general

 * approach is to apply a fractional translation to vertices so that they

 * hit pixel centers and therefore touch the same pixels as in our other

 * pipelines.  Emphasis was placed on finding values so that OGL lines with

 * a slope of +/- 1 hit all the same pixels as our other (software) loops.

 * The stepping in other diagonal lines rendered with OGL may deviate

 * slightly from those rendered with our software loops, but the most

 * important thing is that these magic numbers ensure that all OGL lines

 * hit the same endpoints as our software loops.

 *

 * If you find it necessary to change any of these magic numbers in the

 * future, just be sure that you test the changes across a variety of

 * hardware to ensure consistent rendering everywhere.

 */

void

OGLRenderer_DrawLine(OGLContext *oglc, jint x1, jint y1, jint x2, jint y2)

{

    J2dTraceLn(J2D_TRACE_INFO, "OGLRenderer_DrawLine");

    RETURN_IF_NULL(oglc);

    CHECK_PREVIOUS_OP(GL_LINES);

    if (y1 == y2) {

        // horizontal

        GLfloat fx1 = (GLfloat)x1;

        GLfloat fx2 = (GLfloat)x2;

        GLfloat fy  = ((GLfloat)y1) + 0.2f;

        if (x1 > x2) {

            GLfloat t = fx1; fx1 = fx2; fx2 = t;

        }

        j2d_glVertex2f(fx1+0.2f, fy);

        j2d_glVertex2f(fx2+1.2f, fy);

    } else if (x1 == x2) {

        // vertical

        GLfloat fx  = ((GLfloat)x1) + 0.2f;

        GLfloat fy1 = (GLfloat)y1;

        GLfloat fy2 = (GLfloat)y2;

        if (y1 > y2) {

            GLfloat t = fy1; fy1 = fy2; fy2 = t;

        }

        j2d_glVertex2f(fx, fy1+0.2f);

        j2d_glVertex2f(fx, fy2+1.2f);

    } else {

        // diagonal

        GLfloat fx1 = (GLfloat)x1;

        GLfloat fy1 = (GLfloat)y1;

        GLfloat fx2 = (GLfloat)x2;

        GLfloat fy2 = (GLfloat)y2;

        if (x1 < x2) {

            fx1 += 0.2f;

            fx2 += 1.0f;

        } else {

            fx1 += 0.8f;

            fx2 -= 0.2f;

        }

        if (y1 < y2) {

            fy1 += 0.2f;

            fy2 += 1.0f;

        } else {

            fy1 += 0.8f;

            fy2 -= 0.2f;

        }

        j2d_glVertex2f(fx1, fy1);

        j2d_glVertex2f(fx2, fy2);

    }

}

void

OGLRenderer_DrawRect(OGLContext *oglc, jint x, jint y, jint w, jint h)

{

    J2dTraceLn(J2D_TRACE_INFO, "OGLRenderer_DrawRect");

    if (w < 0 || h < 0) {

        return;

    }

    RETURN_IF_NULL(oglc);

    if (w < 2 || h < 2) {

        // If one dimension is less than 2 then there is no

        // gap in the middle - draw a solid filled rectangle.

        CHECK_PREVIOUS_OP(GL_QUADS);

        GLRECT_BODY_XYWH(x, y, w+1, h+1);

    } else {

        GLfloat fx1 = ((GLfloat)x) + 0.2f;

        GLfloat fy1 = ((GLfloat)y) + 0.2f;

        GLfloat fx2 = fx1 + ((GLfloat)w);

        GLfloat fy2 = fy1 + ((GLfloat)h);

        // Avoid drawing the endpoints twice.

        // Also prefer including the endpoints in the

        // horizontal sections which draw pixels faster.

        CHECK_PREVIOUS_OP(GL_LINES);

        // top

        j2d_glVertex2f(fx1,      fy1);

        j2d_glVertex2f(fx2+1.0f, fy1);

        // right

        j2d_glVertex2f(fx2,      fy1+1.0f);

        j2d_glVertex2f(fx2,      fy2);

        // bottom

        j2d_glVertex2f(fx1,      fy2);

        j2d_glVertex2f(fx2+1.0f, fy2);

        // left

        j2d_glVertex2f(fx1,      fy1+1.0f);

        j2d_glVertex2f(fx1,      fy2);

    }

}

void

OGLRenderer_DrawPoly(OGLContext *oglc,

                     jint nPoints, jint isClosed,

                     jint transX, jint transY,

                     jint *xPoints, jint *yPoints)

{

    jboolean isEmpty = JNI_TRUE;

    jint mx, my;

    jint i;

    J2dTraceLn(J2D_TRACE_INFO, "OGLRenderer_DrawPoly");

    if (xPoints == NULL || yPoints == NULL) {

        J2dRlsTraceLn(J2D_TRACE_ERROR,

                      "OGLRenderer_DrawPoly: points array is null");

        return;

    }

    RETURN_IF_NULL(oglc);

    // Note that BufferedRenderPipe.drawPoly() has already rejected polys

    // with nPoints<2, so we can be certain here that we have nPoints>=2.

    mx = xPoints[0];

    my = yPoints[0];

    CHECK_PREVIOUS_OP(GL_LINE_STRIP);

    for (i = 0; i < nPoints; i++) {

        jint x = xPoints[i];

        jint y = yPoints[i];

        isEmpty = isEmpty && (x == mx && y == my);

        // Translate each vertex by a fraction so that we hit pixel centers.

        j2d_glVertex2f((GLfloat)(x + transX) + 0.5f,

                       (GLfloat)(y + transY) + 0.5f);

    }

    if (isClosed && !isEmpty &&

        (xPoints[nPoints-1] != mx ||

         yPoints[nPoints-1] != my))

    {

        // In this case, the polyline's start and end positions are

        // different and need to be closed manually; we do this by adding

        // one more segment back to the starting position.  Note that we

        // do not need to fill in the last pixel (as we do in the following

        // block) because we are returning to the starting pixel, which

        // has already been filled in.

        j2d_glVertex2f((GLfloat)(mx + transX) + 0.5f,

                       (GLfloat)(my + transY) + 0.5f);

        RESET_PREVIOUS_OP(); // so that we don't leave the line strip open

    } else if (!isClosed || isEmpty) {

        // OpenGL omits the last pixel in a polyline, so we fix this by

        // adding a one-pixel segment at the end.  Also, if the polyline

        // never went anywhere (isEmpty is true), we need to use this

        // workaround to ensure that a single pixel is touched.

        CHECK_PREVIOUS_OP(GL_LINES); // this closes the line strip first

        mx = xPoints[nPoints-1] + transX;

        my = yPoints[nPoints-1] + transY;

        j2d_glVertex2i(mx, my);

        j2d_glVertex2i(mx+1, my+1);

        // no need for RESET_PREVIOUS_OP, as the line strip is no longer open

    } else {

        RESET_PREVIOUS_OP(); // so that we don't leave the line strip open

    }

}

JNIEXPORT void JNICALL

Java_sun_java2d_opengl_OGLRenderer_drawPoly

    (JNIEnv *env, jobject oglr,

     jintArray xpointsArray, jintArray ypointsArray,

     jint nPoints, jboolean isClosed,

     jint transX, jint transY)

{

    jint *xPoints, *yPoints;

    J2dTraceLn(J2D_TRACE_INFO, "OGLRenderer_drawPoly");

    xPoints = (jint *)

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

    if (xPoints != NULL) {

        yPoints = (jint *)

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

        if (yPoints != NULL) {

            OGLContext *oglc = OGLRenderQueue_GetCurrentContext();

            OGLRenderer_DrawPoly(oglc,

                                 nPoints, isClosed,

                                 transX, transY,

                                 xPoints, yPoints);

            // 6358147: reset current state, and ensure rendering is

            // flushed to dest

            if (oglc != NULL) {

                RESET_PREVIOUS_OP();

                j2d_glFlush();

            }

            (*env)->ReleasePrimitiveArrayCritical(env, ypointsArray, yPoints,

                                                  JNI_ABORT);

        }

        (*env)->ReleasePrimitiveArrayCritical(env, xpointsArray, xPoints,

                                              JNI_ABORT);

    }

}

void

OGLRenderer_DrawScanlines(OGLContext *oglc,

                          jint scanlineCount, jint *scanlines)

{

    J2dTraceLn(J2D_TRACE_INFO, "OGLRenderer_DrawScanlines");

    RETURN_IF_NULL(oglc);

    RETURN_IF_NULL(scanlines);

    CHECK_PREVIOUS_OP(GL_LINES);

    while (scanlineCount > 0) {

        // Translate each vertex by a fraction so

        // that we hit pixel centers.

        GLfloat x1 = ((GLfloat)*(scanlines++)) + 0.2f;

        GLfloat x2 = ((GLfloat)*(scanlines++)) + 1.2f;

        GLfloat y  = ((GLfloat)*(scanlines++)) + 0.5f;

        j2d_glVertex2f(x1, y);

        j2d_glVertex2f(x2, y);

        scanlineCount--;

    }

}

void

OGLRenderer_FillRect(OGLContext *oglc, jint x, jint y, jint w, jint h)

{

    J2dTraceLn(J2D_TRACE_INFO, "OGLRenderer_FillRect");

    if (w <= 0 || h <= 0) {

        return;

    }

    RETURN_IF_NULL(oglc);

    CHECK_PREVIOUS_OP(GL_QUADS);

    GLRECT_BODY_XYWH(x, y, w, h);

}

void

OGLRenderer_FillSpans(OGLContext *oglc, jint spanCount, jint *spans)

{

    J2dTraceLn(J2D_TRACE_INFO, "OGLRenderer_FillSpans");

    RETURN_IF_NULL(oglc);

    RETURN_IF_NULL(spans);

    CHECK_PREVIOUS_OP(GL_QUADS);

    while (spanCount > 0) {

        jint x1 = *(spans++);

        jint y1 = *(spans++);

        jint x2 = *(spans++);

        jint y2 = *(spans++);

        GLRECT_BODY_XYXY(x1, y1, x2, y2);

        spanCount--;

    }

}

#define FILL_PGRAM(fx11, fy11, dx21, dy21, dx12, dy12) \

    do { \

        j2d_glVertex2f(fx11,               fy11); \

        j2d_glVertex2f(fx11 + dx21,        fy11 + dy21); \

        j2d_glVertex2f(fx11 + dx21 + dx12, fy11 + dy21 + dy12); \

        j2d_glVertex2f(fx11 + dx12,        fy11 + dy12); \

    } while (0)

void

OGLRenderer_FillParallelogram(OGLContext *oglc,

                              jfloat fx11, jfloat fy11,

                              jfloat dx21, jfloat dy21,

                              jfloat dx12, jfloat dy12)

{

    J2dTraceLn6(J2D_TRACE_INFO,

                "OGLRenderer_FillParallelogram "

                "(x=%6.2f y=%6.2f "

                "dx1=%6.2f dy1=%6.2f "

                "dx2=%6.2f dy2=%6.2f)",

                fx11, fy11,

                dx21, dy21,

                dx12, dy12);

    RETURN_IF_NULL(oglc);

    CHECK_PREVIOUS_OP(GL_QUADS);

    FILL_PGRAM(fx11, fy11, dx21, dy21, dx12, dy12);

}

void

OGLRenderer_DrawParallelogram(OGLContext *oglc,

                              jfloat fx11, jfloat fy11,

                              jfloat dx21, jfloat dy21,

                              jfloat dx12, jfloat dy12,

                              jfloat lwr21, jfloat lwr12)

{

    // dx,dy for line width in the "21" and "12" directions.

    jfloat ldx21 = dx21 * lwr21;

    jfloat ldy21 = dy21 * lwr21;

    jfloat ldx12 = dx12 * lwr12;

    jfloat ldy12 = dy12 * lwr12;

    // calculate origin of the outer parallelogram

    jfloat ox11 = fx11 - (ldx21 + ldx12) / 2.0f;

    jfloat oy11 = fy11 - (ldy21 + ldy12) / 2.0f;

    J2dTraceLn8(J2D_TRACE_INFO,

                "OGLRenderer_DrawParallelogram "

                "(x=%6.2f y=%6.2f "

                "dx1=%6.2f dy1=%6.2f lwr1=%6.2f "

                "dx2=%6.2f dy2=%6.2f lwr2=%6.2f)",

                fx11, fy11,

                dx21, dy21, lwr21,

                dx12, dy12, lwr12);

    RETURN_IF_NULL(oglc);

    CHECK_PREVIOUS_OP(GL_QUADS);

    // Only need to generate 4 quads if the interior still

    // has a hole in it (i.e. if the line width ratio was

    // less than 1.0)

    if (lwr21 < 1.0f && lwr12 < 1.0f) {

        // Note: "TOP", "BOTTOM", "LEFT" and "RIGHT" here are

        // relative to whether the dxNN variables are positive

        // and negative.  The math works fine regardless of

        // their signs, but for conceptual simplicity the

        // comments will refer to the sides as if the dxNN

        // were all positive.  "TOP" and "BOTTOM" segments

        // are defined by the dxy21 deltas.  "LEFT" and "RIGHT"

        // segments are defined by the dxy12 deltas.

        // Each segment includes its starting corner and comes

        // to just short of the following corner.  Thus, each

        // corner is included just once and the only lengths

        // needed are the original parallelogram delta lengths

        // and the "line width deltas".  The sides will cover

        // the following relative territories:

        //

        //     T T T T T R

        //      L         R

        //       L         R

        //        L         R

        //         L         R

        //          L B B B B B

        // TOP segment, to left side of RIGHT edge

        // "width" of original pgram, "height" of hor. line size

        fx11 = ox11;

        fy11 = oy11;

        FILL_PGRAM(fx11, fy11, dx21, dy21, ldx12, ldy12);

        // RIGHT segment, to top of BOTTOM edge

        // "width" of vert. line size , "height" of original pgram

        fx11 = ox11 + dx21;

        fy11 = oy11 + dy21;

        FILL_PGRAM(fx11, fy11, ldx21, ldy21, dx12, dy12);

        // BOTTOM segment, from right side of LEFT edge

        // "width" of original pgram, "height" of hor. line size

        fx11 = ox11 + dx12 + ldx21;

        fy11 = oy11 + dy12 + ldy21;

        FILL_PGRAM(fx11, fy11, dx21, dy21, ldx12, ldy12);

        // LEFT segment, from bottom of TOP edge

        // "width" of vert. line size , "height" of inner pgram

        fx11 = ox11 + ldx12;

        fy11 = oy11 + ldy12;

        FILL_PGRAM(fx11, fy11, ldx21, ldy21, dx12, dy12);

    } else {

        // The line width ratios were large enough to consume

        // the entire hole in the middle of the parallelogram

        // so we can just issue one large quad for the outer

        // parallelogram.

        dx21 += ldx21;

        dy21 += ldy21;

        dx12 += ldx12;

        dy12 += ldy12;

        FILL_PGRAM(ox11, oy11, dx21, dy21, dx12, dy12);

    }

}

static GLhandleARB aaPgramProgram = 0;

/*

 * This shader fills the space between an outer and inner parallelogram.

 * It can be used to draw an outline by specifying both inner and outer

 * values.  It fills pixels by estimating what portion falls inside the

 * outer shape, and subtracting an estimate of what portion falls inside

 * the inner shape.  Specifying both inner and outer values produces a

 * standard "wide outline".  Specifying an inner shape that falls far

 * outside the outer shape allows the same shader to fill the outer

 * shape entirely since pixels that fall within the outer shape are never

 * inside the inner shape and so they are filled based solely on their

 * coverage of the outer shape.

 *

 * The setup code renders this shader over the bounds of the outer

 * shape (or the only shape in the case of a fill operation) and

 * sets the texture 0 coordinates so that 0,0=>0,1=>1,1=>1,0 in those

 * texture coordinates map to the four corners of the parallelogram.

 * Similarly the texture 1 coordinates map the inner shape to the

 * unit square as well, but in a different coordinate system.

 *

 * When viewed in the texture coordinate systems the parallelograms

 * we are filling are unit squares, but the pixels have then become

 * tiny parallelograms themselves.  Both of the texture coordinate

 * systems are affine transforms so the rate of change in X and Y

 * of the texture coordinates are essentially constants and happen

 * to correspond to the size and direction of the slanted sides of

 * the distorted pixels relative to the "square mapped" boundary

 * of the parallelograms.

 *

 * The shader uses the dFdx() and dFdy() functions to measure the "rate

 * of change" of these texture coordinates and thus gets an accurate

 * measure of the size and shape of a pixel relative to the two

 * parallelograms.  It then uses the bounds of the size and shape

 * of a pixel to intersect with the unit square to estimate the

 * coverage of the pixel.  Unfortunately, without a lot more work

 * to calculate the exact area of intersection between a unit

 * square (the original parallelogram) and a parallelogram (the

 * distorted pixel), this shader only approximates the pixel

 * coverage, but emperically the estimate is very useful and

 * produces visually pleasing results, if not theoretically accurate.

 */

static const char *aaPgramShaderSource =

    "void main() {"

    // Calculate the vectors for the "legs" of the pixel parallelogram

    // for the outer parallelogram.

    "    vec2 oleg1 = dFdx(gl_TexCoord[0].st);"

    "    vec2 oleg2 = dFdy(gl_TexCoord[0].st);"

    // Calculate the bounds of the distorted pixel parallelogram.

    "    vec2 corner = gl_TexCoord[0].st - (oleg1+oleg2)/2.0;"

    "    vec2 omin = min(corner, corner+oleg1);"

    "    omin = min(omin, corner+oleg2);"

    "    omin = min(omin, corner+oleg1+oleg2);"

    "    vec2 omax = max(corner, corner+oleg1);"

    "    omax = max(omax, corner+oleg2);"

    "    omax = max(omax, corner+oleg1+oleg2);"

    // Calculate the vectors for the "legs" of the pixel parallelogram

    // for the inner parallelogram.

    "    vec2 ileg1 = dFdx(gl_TexCoord[1].st);"

    "    vec2 ileg2 = dFdy(gl_TexCoord[1].st);"

    // Calculate the bounds of the distorted pixel parallelogram.

    "    corner = gl_TexCoord[1].st - (ileg1+ileg2)/2.0;"

    "    vec2 imin = min(corner, corner+ileg1);"