/**
* Initializes the OpenGL logic op state to XOR mode. Blending is disabled
* before enabling logic op mode. The XOR pixel value will be applied
* later in the OGLContext_SetColor() method.
*/
void
OGLContext_SetXorComposite(OGLContext *oglc, jint xorPixel)
{
J2dTraceLn1(J2D_TRACE_INFO,
"OGLContext_SetXorComposite: xorPixel=%08x", xorPixel);
RETURN_IF_NULL(oglc);
CHECK_PREVIOUS_OP(OGL_STATE_CHANGE);
// disable blending mode
if (oglc->compState == sun_java2d_SunGraphics2D_COMP_ALPHA) {
j2d_glDisable(GL_BLEND);
}
// enable XOR mode
j2d_glEnable(GL_COLOR_LOGIC_OP);
j2d_glLogicOp(GL_XOR);
// set up the alpha test so that we discard transparent fragments (this
// is primarily useful for rendering text in XOR mode)
j2d_glEnable(GL_ALPHA_TEST);
j2d_glAlphaFunc(GL_NOTEQUAL, 0.0f);
// update state
oglc->compState = sun_java2d_SunGraphics2D_COMP_XOR;
oglc->xorPixel = xorPixel;
oglc->extraAlpha = 1.0f;
}
/**
* Enables the LCD text shader and updates any related state, such as the
* gamma lookup table textures.
*/
static jboolean
OGLTR_EnableLCDGlyphModeState(GLuint glyphTextureID, jint contrast)
{
// bind the texture containing glyph data to texture unit 0
j2d_glActiveTextureARB(GL_TEXTURE0_ARB);
j2d_glBindTexture(GL_TEXTURE_2D, glyphTextureID);
// bind the texture tile containing destination data to texture unit 1
j2d_glActiveTextureARB(GL_TEXTURE1_ARB);
if (cachedDestTextureID == 0) {
cachedDestTextureID =
OGLContext_CreateBlitTexture(GL_RGB8, GL_RGB,
OGLTR_CACHED_DEST_WIDTH,
OGLTR_CACHED_DEST_HEIGHT);
if (cachedDestTextureID == 0) {
return JNI_FALSE;
}
}
j2d_glBindTexture(GL_TEXTURE_2D, cachedDestTextureID);
// note that GL_TEXTURE_2D was already enabled for texture unit 0,
// but we need to explicitly enable it for texture unit 1
j2d_glEnable(GL_TEXTURE_2D);
// create the LCD text shader, if necessary
if (lcdTextProgram == 0) {
lcdTextProgram = OGLTR_CreateLCDTextProgram();
if (lcdTextProgram == 0) {
return JNI_FALSE;
}
}
// enable the LCD text shader
j2d_glUseProgramObjectARB(lcdTextProgram);
// update the current contrast settings, if necessary
if (lastLCDContrast != contrast) {
if (!OGLTR_UpdateLCDTextContrast(contrast)) {
return JNI_FALSE;
}
lastLCDContrast = contrast;
}
// update the current color settings
if (!OGLTR_UpdateLCDTextColor(contrast)) {
return JNI_FALSE;
}
// bind the gamma LUT textures
j2d_glActiveTextureARB(GL_TEXTURE2_ARB);
j2d_glBindTexture(GL_TEXTURE_3D, invGammaLutTextureID);
j2d_glEnable(GL_TEXTURE_3D);
j2d_glActiveTextureARB(GL_TEXTURE3_ARB);
j2d_glBindTexture(GL_TEXTURE_3D, gammaLutTextureID);
j2d_glEnable(GL_TEXTURE_3D);
return JNI_TRUE;
}
/**
* Sets up a complex (shape) clip using the OpenGL depth buffer. This
* method prepares the depth buffer so that the clip Region spans can
* be "rendered" into it. The depth buffer is first cleared, then the
* depth func is setup so that when we render the clip spans,
* nothing is rendered into the color buffer, but for each pixel that would
* be rendered, a non-zero value is placed into that location in the depth
* buffer. With depth test enabled, pixels will only be rendered into the
* color buffer if the corresponding value at that (x,y) location in the
* depth buffer differs from the incoming depth value.
*/
void
OGLContext_BeginShapeClip(OGLContext *oglc)
{
J2dTraceLn(J2D_TRACE_INFO, "OGLContext_BeginShapeClip");
RETURN_IF_NULL(oglc);
RESET_PREVIOUS_OP();
j2d_glDisable(GL_SCISSOR_TEST);
// enable depth test and clear depth buffer so that depth values are at
// their maximum; also set the depth func to GL_ALWAYS so that the
// depth values of the clip spans are forced into the depth buffer
j2d_glEnable(GL_DEPTH_TEST);
j2d_glClearDepth(1.0);
j2d_glClear(GL_DEPTH_BUFFER_BIT);
j2d_glDepthFunc(GL_ALWAYS);
// disable writes into the color buffer while we set up the clip
j2d_glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
// save current transform
j2d_glMatrixMode(GL_MODELVIEW);
j2d_glPushMatrix();
// use identity transform plus slight translation in the z-axis when
// setting the clip spans; this will push the clip spans (which would
// normally be at z=0) to the z=1 plane to give them some depth
j2d_glLoadIdentity();
j2d_glTranslatef(0.0f, 0.0f, 1.0f);
}
/**
* Sets the OpenGL scissor bounds to the provided rectangular clip bounds.
*/
void
OGLContext_SetRectClip(OGLContext *oglc, OGLSDOps *dstOps,
jint x1, jint y1, jint x2, jint y2)
{
jint width = x2 - x1;
jint height = y2 - y1;
J2dTraceLn4(J2D_TRACE_INFO,
"OGLContext_SetRectClip: x=%d y=%d w=%d h=%d",
x1, y1, width, height);
RETURN_IF_NULL(dstOps);
RETURN_IF_NULL(oglc);
CHECK_PREVIOUS_OP(OGL_STATE_CHANGE);
if ((width < 0) || (height < 0)) {
// use an empty scissor rectangle when the region is empty
width = 0;
height = 0;
}
j2d_glDisable(GL_DEPTH_TEST);
j2d_glEnable(GL_SCISSOR_TEST);
// the scissor rectangle is specified using the lower-left
// origin of the clip region (in the framebuffer's coordinate
// space), so we must account for the x/y offsets of the
// destination surface
j2d_glScissor(dstOps->xOffset + x1,
dstOps->yOffset + dstOps->height - (y1 + height),
width, height);
}
/**
* Initializes the alpha channel of the current surface so that it contains
* fully opaque alpha values.
*/
static void
OGLContext_InitAlphaChannel()
{
GLboolean scissorEnabled;
J2dTraceLn(J2D_TRACE_INFO, "OGLContext_InitAlphaChannel");
// it is possible for the scissor test to be enabled at this point;
// if it is, disable it temporarily since it can affect the glClear() op
scissorEnabled = j2d_glIsEnabled(GL_SCISSOR_TEST);
if (scissorEnabled) {
j2d_glDisable(GL_SCISSOR_TEST);
}
// set the color mask so that we only affect the alpha channel
j2d_glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_TRUE);
// clear the color buffer so that the alpha channel is fully opaque
j2d_glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
j2d_glClear(GL_COLOR_BUFFER_BIT);
// restore the color mask (as it was set in OGLContext_SetViewport())
j2d_glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_FALSE);
// re-enable scissor test, only if it was enabled earlier
if (scissorEnabled) {
j2d_glEnable(GL_SCISSOR_TEST);
}
}
void
OGLTR_EnableGlyphVertexCache(OGLContext *oglc)
{
J2dTraceLn(J2D_TRACE_INFO, "OGLTR_EnableGlyphVertexCache");
if (glyphCache == NULL) {
if (!OGLTR_InitGlyphCache(JNI_FALSE)) {
return;
}
}
j2d_glEnable(GL_TEXTURE_2D);
j2d_glBindTexture(GL_TEXTURE_2D, glyphCache->cacheID);
j2d_glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
// for grayscale/monochrome text, the current OpenGL source color
// is modulated with the glyph image as part of the texture
// application stage, so we use GL_MODULATE here
OGLC_UPDATE_TEXTURE_FUNCTION(oglc, GL_MODULATE);
}
/**
* Initializes the OpenGL blending state. XOR mode is disabled and the
* appropriate blend functions are setup based on the AlphaComposite rule
* constant.
*/
void
OGLContext_SetAlphaComposite(OGLContext *oglc,
jint rule, jfloat extraAlpha, jint flags)
{
J2dTraceLn1(J2D_TRACE_INFO,
"OGLContext_SetAlphaComposite: flags=%d", flags);
RETURN_IF_NULL(oglc);
CHECK_PREVIOUS_OP(OGL_STATE_CHANGE);
// disable XOR mode
if (oglc->compState == sun_java2d_SunGraphics2D_COMP_XOR) {
j2d_glDisable(GL_COLOR_LOGIC_OP);
j2d_glDisable(GL_ALPHA_TEST);
}
// we can safely disable blending when:
// - comp is SrcNoEa or SrcOverNoEa, and
// - the source is opaque
// (turning off blending can have a large positive impact on
// performance)
if ((rule == RULE_Src || rule == RULE_SrcOver) &&
(extraAlpha == 1.0f) &&
(flags & OGLC_SRC_IS_OPAQUE))
{
J2dTraceLn1(J2D_TRACE_VERBOSE,
" disabling alpha comp: rule=%d ea=1.0 src=opq", rule);
j2d_glDisable(GL_BLEND);
} else {
J2dTraceLn2(J2D_TRACE_VERBOSE,
" enabling alpha comp: rule=%d ea=%f", rule, extraAlpha);
j2d_glEnable(GL_BLEND);
j2d_glBlendFunc(StdBlendRules[rule].src, StdBlendRules[rule].dst);
}
// update state
oglc->compState = sun_java2d_SunGraphics2D_COMP_ALPHA;
oglc->extraAlpha = extraAlpha;
}
/**
* Used to track whether we are within a series of simple primitive operations
* or texturing operations. The op parameter determines the nature of the
* operation that is to follow. Valid values for this op parameter are:
*
* GL_QUADS
* GL_LINES
* GL_LINE_LOOP
* GL_LINE_STRIP
* (basically any of the valid parameters for glBegin())
*
* GL_TEXTURE_2D
* GL_TEXTURE_RECTANGLE_ARB
*
* OGL_STATE_RESET
* OGL_STATE_CHANGE
* OGL_STATE_MASK_OP
* OGL_STATE_GLYPH_OP
*
* Note that the above constants are guaranteed to be unique values. The
* last few are defined to be negative values to differentiate them from
* the core GL* constants, which are defined to be non-negative.
*
* For simple primitives, this method allows us to batch similar primitives
* within the same glBegin()/glEnd() pair. For example, if we have 100
* consecutive FILL_RECT operations, we only have to call glBegin(GL_QUADS)
* for the first op, and then subsequent operations will consist only of
* glVertex*() calls, which helps improve performance. The glEnd() call
* only needs to be issued before an operation that cannot happen within a
* glBegin()/glEnd() pair (e.g. updating the clip), or one that requires a
* different primitive mode (e.g. GL_LINES).
*
* For operations that involve texturing, this method helps us to avoid
* calling glEnable(GL_TEXTURE_2D) and glDisable(GL_TEXTURE_2D) around each
* operation. For example, if we have an alternating series of ISO_BLIT
* and MASK_BLIT operations (both of which involve texturing), we need
* only to call glEnable(GL_TEXTURE_2D) before the first ISO_BLIT operation.
* The glDisable(GL_TEXTURE_2D) call only needs to be issued before an
* operation that cannot (or should not) happen while texturing is enabled
* (e.g. a context change, or a simple primitive operation like GL_QUADS).
*/
void
OGLRenderQueue_CheckPreviousOp(jint op)
{
if (previousOp == op) {
// The op is the same as last time, so we can return immediately.
return;
}
J2dTraceLn1(J2D_TRACE_VERBOSE,
"OGLRenderQueue_CheckPreviousOp: new op=%d", op);
switch (previousOp) {
case GL_TEXTURE_2D:
case GL_TEXTURE_RECTANGLE_ARB:
if (op == OGL_STATE_CHANGE) {
// Optimization: Certain state changes (those marked as
// OGL_STATE_CHANGE) are allowed while texturing is enabled.
// In this case, we can allow previousOp to remain as it is and
// then return early.
return;
} else {
// Otherwise, op must be a primitive operation, or a reset, so
// we will disable texturing.
j2d_glDisable(previousOp);
// This next step of binding to zero should not be strictly
// necessary, but on some older Nvidia boards (e.g. GeForce 2)
// problems will arise if GL_TEXTURE_2D and
// GL_TEXTURE_RECTANGLE_ARB are bound at the same time, so we
// will do this just to be safe.
j2d_glBindTexture(previousOp, 0);
}
break;
case OGL_STATE_MASK_OP:
OGLVertexCache_DisableMaskCache(oglc);
break;
case OGL_STATE_GLYPH_OP:
OGLTR_DisableGlyphVertexCache(oglc);
break;
case OGL_STATE_PGRAM_OP:
OGLRenderer_DisableAAParallelogramProgram();
break;
case OGL_STATE_RESET:
case OGL_STATE_CHANGE:
// No-op
break;
default:
// In this case, op must be one of:
// - the start of a different primitive type (glBegin())
// - a texturing operation
// - a state change (not allowed within glBegin()/glEnd() pairs)
// - a reset
// so we must first complete the previous primitive operation.
j2d_glEnd();
break;
}
switch (op) {
case GL_TEXTURE_2D:
case GL_TEXTURE_RECTANGLE_ARB:
// We are starting a texturing operation, so enable texturing.
j2d_glEnable(op);
break;
case OGL_STATE_MASK_OP:
OGLVertexCache_EnableMaskCache(oglc);
break;
case OGL_STATE_GLYPH_OP:
OGLTR_EnableGlyphVertexCache(oglc);
break;
case OGL_STATE_PGRAM_OP:
OGLRenderer_EnableAAParallelogramProgram();
break;
case OGL_STATE_RESET:
case OGL_STATE_CHANGE:
// No-op
break;
default:
// We are starting a primitive operation, so call glBegin() with
// the given primitive type.
j2d_glBegin(op);
break;
}
previousOp = op;
}
