/*
* Mesa 3-D graphics library
*
* Copyright (C) 1999-2007 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Authors:
* Keith Whitwell <keithw@vmware.com>
*/
/**
* This is where we handle assigning vertex colors based on front/back
* facing, compute polygon offset and handle glPolygonMode().
*/
static void TAG(triangle)(struct gl_context *ctx, GLuint e0, GLuint e1, GLuint e2 )
{
struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
SScontext *swsetup = SWSETUP_CONTEXT(ctx);
SWvertex *verts = SWSETUP_CONTEXT(ctx)->verts;
SWvertex *v[3];
GLfloat z[3];
GLfloat offset, oz0, oz1, oz2;
GLenum mode = GL_FILL;
GLuint facing = 0;
GLchan saved_color[3][4] = { { 0 } };
GLfloat saved_col0[3][4] = { { 0 } };
GLfloat saved_spec[3][4] = { { 0 } };
v[0] = &verts[e0];
v[1] = &verts[e1];
v[2] = &verts[e2];
if (IND & (SS_TWOSIDE_BIT | SS_OFFSET_BIT | SS_UNFILLED_BIT))
{
GLfloat ex = v[0]->attrib[VARYING_SLOT_POS][0] - v[2]->attrib[VARYING_SLOT_POS][0];
GLfloat ey = v[0]->attrib[VARYING_SLOT_POS][1] - v[2]->attrib[VARYING_SLOT_POS][1];
GLfloat fx = v[1]->attrib[VARYING_SLOT_POS][0] - v[2]->attrib[VARYING_SLOT_POS][0];
GLfloat fy = v[1]->attrib[VARYING_SLOT_POS][1] - v[2]->attrib[VARYING_SLOT_POS][1];
GLfloat cc = ex*fy - ey*fx;
if (IND & (SS_TWOSIDE_BIT | SS_UNFILLED_BIT))
{
facing = (cc < 0.0F) ^ _mesa_polygon_get_front_bit(ctx);
if (IND & SS_UNFILLED_BIT)
mode = facing ? ctx->Polygon.BackMode : ctx->Polygon.FrontMode;
if (facing == 1) {
if (IND & SS_TWOSIDE_BIT) {
if (VB->BackfaceColorPtr) {
GLfloat (*vbcolor)[4] = VB->BackfaceColorPtr->data;
if (swsetup->intColors) {
COPY_CHAN4(saved_color[0], v[0]->color);
COPY_CHAN4(saved_color[1], v[1]->color);
COPY_CHAN4(saved_color[2], v[2]->color);
}
else {
COPY_4V(saved_col0[0], v[0]->attrib[VARYING_SLOT_COL0]);
COPY_4V(saved_col0[1], v[1]->attrib[VARYING_SLOT_COL0]);
COPY_4V(saved_col0[2], v[2]->attrib[VARYING_SLOT_COL0]);
}
if (VB->BackfaceColorPtr->stride) {
if (swsetup->intColors) {
SS_COLOR(v[0]->color, vbcolor[e0]);
SS_COLOR(v[1]->color, vbcolor[e1]);
SS_COLOR(v[2]->color, vbcolor[e2]);
}
else {
COPY_4V(v[0]->attrib[VARYING_SLOT_COL0], vbcolor[e0]);
COPY_4V(v[1]->attrib[VARYING_SLOT_COL0], vbcolor[e1]);
COPY_4V(v[2]->attrib[VARYING_SLOT_COL0], vbcolor[e2]);
}
}
else {
/* flat shade */
if (swsetup->intColors) {
SS_COLOR(v[0]->color, vbcolor[0]);
SS_COLOR(v[1]->color, vbcolor[0]);
SS_COLOR(v[2]->color, vbcolor[0]);
}
else {
COPY_4V(v[0]->attrib[VARYING_SLOT_COL0], vbcolor[0]);
COPY_4V(v[1]->attrib[VARYING_SLOT_COL0], vbcolor[0]);
COPY_4V(v[2]->attrib[VARYING_SLOT_COL0], vbcolor[0]);
}
}
}
if (VB->BackfaceSecondaryColorPtr) {
GLfloat (*vbspec)[4] = VB->BackfaceSecondaryColorPtr->data;
COPY_4V(saved_spec[0], v[0]->attrib[VARYING_SLOT_COL1]);
COPY_4V(saved_spec[1], v[1]->attrib[VARYING_SLOT_COL1]);
COPY_4V(saved_spec[2], v[2]->attrib[VARYING_SLOT_COL1]);
if (VB->BackfaceSecondaryColorPtr->stride) {
SS_SPEC(v[0]->attrib[VARYING_SLOT_COL1], vbspec[e0]);
SS_SPEC(v[1]->attrib[VARYING_SLOT_COL1], vbspec[e1]);
SS_SPEC(v[2]->attrib[VARYING_SLOT_COL1], vbspec[e2]);
}
else {
SS_SPEC(v[0]->attrib[VARYING_SLOT_COL1], vbspec[0]);
SS_SPEC(v[1]->attrib[VARYING_SLOT_COL1], vbspec[0]);
SS_SPEC(v[2]->attrib[VARYING_SLOT_COL1], vbspec[0]);
}
}
}
}
}
if (IND & SS_OFFSET_BIT) {
const GLfloat max = ctx->DrawBuffer->_DepthMaxF;
/* save original Z values (restored later) */
z[0] = v[0]->attrib[VARYING_SLOT_POS][2];
z[1] = v[1]->attrib[VARYING_SLOT_POS][2];
z[2] = v[2]->attrib[VARYING_SLOT_POS][2];
/* Note that Z values are already scaled to [0,65535] (for example)
* so no MRD value is used here.
*/
offset = ctx->Polygon.OffsetUnits;
if (cc * cc > 1e-16F) {
const GLfloat ez = z[0] - z[2];
const GLfloat fz = z[1] - z[2];
const GLfloat oneOverArea = 1.0F / cc;
const GLfloat dzdx = fabsf((ey * fz - ez * fy) * oneOverArea);
const GLfloat dzdy = fabsf((ez * fx - ex * fz) * oneOverArea);
offset += MAX2(dzdx, dzdy) * ctx->Polygon.OffsetFactor;
}
/* new Z values */
oz0 = CLAMP(v[0]->attrib[VARYING_SLOT_POS][2] + offset, 0.0F, max);
oz1 = CLAMP(v[1]->attrib[VARYING_SLOT_POS][2] + offset, 0.0F, max);
oz2 = CLAMP(v[2]->attrib[VARYING_SLOT_POS][2] + offset, 0.0F, max);
}
}
if (mode == GL_POINT) {
if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetPoint) {
v[0]->attrib[VARYING_SLOT_POS][2] = oz0;
v[1]->attrib[VARYING_SLOT_POS][2] = oz1;
v[2]->attrib[VARYING_SLOT_POS][2] = oz2;
}
_swsetup_render_tri(ctx, e0, e1, e2, facing, _swsetup_edge_render_point_tri);
} else if (mode == GL_LINE) {
if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetLine) {
v[0]->attrib[VARYING_SLOT_POS][2] = oz0;
v[1]->attrib[VARYING_SLOT_POS][2] = oz1;
v[2]->attrib[VARYING_SLOT_POS][2] = oz2;
}
_swsetup_render_tri(ctx, e0, e1, e2, facing, _swsetup_edge_render_line_tri);
} else {
if ((IND & SS_OFFSET_BIT) && ctx->Polygon.OffsetFill) {
v[0]->attrib[VARYING_SLOT_POS][2] = oz0;
v[1]->attrib[VARYING_SLOT_POS][2] = oz1;
v[2]->attrib[VARYING_SLOT_POS][2] = oz2;
}
_swrast_Triangle( ctx, v[0], v[1], v[2] );
}
/*
* Restore original vertex colors, etc.
*/
if (IND & SS_OFFSET_BIT) {
v[0]->attrib[VARYING_SLOT_POS][2] = z[0];
v[1]->attrib[VARYING_SLOT_POS][2] = z[1];
v[2]->attrib[VARYING_SLOT_POS][2] = z[2];
}
if (IND & SS_TWOSIDE_BIT) {
if (facing == 1) {
if (VB->BackfaceColorPtr) {
if (swsetup->intColors) {
COPY_CHAN4(v[0]->color, saved_color[0]);
COPY_CHAN4(v[1]->color, saved_color[1]);
COPY_CHAN4(v[2]->color, saved_color[2]);
}
else {
COPY_4V(v[0]->attrib[VARYING_SLOT_COL0], saved_col0[0]);
COPY_4V(v[1]->attrib[VARYING_SLOT_COL0], saved_col0[1]);
COPY_4V(v[2]->attrib[VARYING_SLOT_COL0], saved_col0[2]);
}
}
if (VB->BackfaceSecondaryColorPtr) {
COPY_4V(v[0]->attrib[VARYING_SLOT_COL1], saved_spec[0]);
COPY_4V(v[1]->attrib[VARYING_SLOT_COL1], saved_spec[1]);
COPY_4V(v[2]->attrib[VARYING_SLOT_COL1], saved_spec[2]);
}
}
}
}
/* Need to fixup edgeflags when decomposing to triangles:
*/
static void TAG(quadfunc)( struct gl_context *ctx, GLuint v0,
GLuint v1, GLuint v2, GLuint v3 )
{
if (IND & SS_UNFILLED_BIT) {
struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
if (VB->EdgeFlag) { /* XXX this test shouldn't be needed (bug 12614) */
GLubyte ef1 = VB->EdgeFlag[v1];
GLubyte ef3 = VB->EdgeFlag[v3];
VB->EdgeFlag[v1] = 0;
TAG(triangle)( ctx, v0, v1, v3 );
VB->EdgeFlag[v1] = ef1;
VB->EdgeFlag[v3] = 0;
TAG(triangle)( ctx, v1, v2, v3 );
VB->EdgeFlag[v3] = ef3;
}
} else {
TAG(triangle)( ctx, v0, v1, v3 );
TAG(triangle)( ctx, v1, v2, v3 );
}
}
static void TAG(init)( void )
{
tri_tab[IND] = TAG(triangle);
quad_tab[IND] = TAG(quadfunc);
}
#undef IND
#undef TAG