diff options
Diffstat (limited to 'src/video/trail.c')
| -rw-r--r-- | src/video/trail.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/src/video/trail.c b/src/video/trail.c new file mode 100644 index 0000000..f1b276d --- /dev/null +++ b/src/video/trail.c @@ -0,0 +1,224 @@ +#include "video/video.h" +#include "game/game.h" + +#define TEX_SPLIT (1.0 - BOW_DIST2) / (1 - BOW_DIST1) +#undef TEX_SPLIT + +static float normal1[] = { 1.0, 0.0, 0.0 }; +static float normal2[] = { 0.0, 1.0, 0.0 }; + +/* + getDists returns the minimum distance from (the wall) *line to the + specified (eye) point + the z component is ignored + */ +float getDist(segment2 *s, float* eye) { + float n[2]; + float tmp[2]; + n[0] = s->vStart.v[0] + s->vDirection.v[1]; + n[1] = s->vStart.v[1] - s->vDirection.v[0]; + tmp[0] = eye[0] - s->vStart.v[0]; + tmp[1] = eye[1] - s->vStart.v[1]; + if(n[0] == n[1] == 0) return length(tmp); + return abs(scalarprod2(n, tmp) / length(n)); +} + +/* + getSegmentEnd[XY]() returns the end point of the + last trail segment line (before the lightcycles bow starts) +*/ + +float dists[] = { BOW_DIST2, BOW_DIST3, BOW_DIST1, 0 }; + +float getSegmentEndX(Data *data, int dist) { + float tlength, blength; + segment2 *s = data->trails + data->trailOffset; + + if(dirsX[data->dir] == 0) + return s->vStart.v[0] + s->vDirection.v[0]; + + tlength = segment2_Length(s); + blength = (tlength < 2 * BOW_LENGTH) ? tlength / 2 : BOW_LENGTH; + return + s->vStart.v[0] + s->vDirection.v[0] - + dists[dist] * blength * dirsX[ data->dir ]; +} + +float getSegmentEndY(Data *data, int dist) { + float tlength, blength; + segment2 *s = data->trails + data->trailOffset; + + if(dirsY[data->dir] == 0) + return s->vStart.v[1] + s->vDirection.v[1]; + + tlength = segment2_Length(s); + blength = (tlength < 2 * BOW_LENGTH) ? tlength / 2 : BOW_LENGTH; + return + s->vStart.v[1] + s->vDirection.v[1] - + dists[dist] * blength * dirsY[ data->dir ]; +} + +/* getSegmentEndUV() calculates the texture coordinates for the last segment */ +float getSegmentEndUV(segment2 *s, Data *data) { + float tlength, blength; + tlength = segment2_Length(s); + blength = (tlength < 2 * BOW_LENGTH) ? tlength / 2 : BOW_LENGTH; + return (tlength - 2 * blength) / DECAL_WIDTH; +} + +/* getSegmentUV gets UV coordinates for an ordinary segment */ +float getSegmentUV(segment2 *s) { + return segment2_Length(s) / DECAL_WIDTH; +} + +/* + drawTrailLines() draws a white line on top of each trail segment + the alpha value is reduced with increasing distance to the player +*/ + +void drawTrailLines(Player *p, PlayerVisual *pV) { + segment2 *s; + float height; + + float *normal; + float dist; + float alpha; + Data *data; + Camera *cam; + + float trail_top[] = { 1.0, 1.0, 1.0, 1.0 }; + + data = p->data; + cam = p->camera; + + height = data->trail_height; + if(height <= 0) return; + + /* + glDepthMask(GL_FALSE); + glDisable(GL_DEPTH_TEST); + */ + + if (gSettingsCache.antialias_lines) { + glEnable(GL_LINE_SMOOTH); /* enable line antialiasing */ + } + + glEnable(GL_BLEND); + glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); + glDisable(GL_LIGHTING); + + glBegin(GL_LINES); + + s = data->trails; + while(s != data->trails + data->trailOffset) { + /* the current line is not drawn */ + /* compute distance from line to eye point */ + dist = getDist(s, cam->cam); + alpha = (game2->rules.grid_size - dist / 2) / game2->rules.grid_size; + // trail_top[3] = alpha; + glColor4fv(trail_top); + + if(s->vDirection.v[1] == 0) normal = normal1; + else normal = normal2; + glNormal3fv(normal); + glVertex3f(s->vStart.v[0], + s->vStart.v[1], + height); + glVertex3f(s->vStart.v[0] + s->vDirection.v[0], + s->vStart.v[1] + s->vDirection.v[1], + height); + s++; + polycount++; + } + glEnd(); + + /* compute distance from line to eye point */ + dist = getDist(s, cam->cam); + alpha = (game2->rules.grid_size - dist / 2) / game2->rules.grid_size; + // trail_top[3] = alpha; + glColor4fv(trail_top); + + glBegin(GL_LINES); + + glVertex3f(s->vStart.v[0], + s->vStart.v[1], + height); + glVertex3f( getSegmentEndX(data, 0), + getSegmentEndY(data, 0), + height ); + + glEnd(); + + /* glEnable(GL_LIGHTING); */ + glDisable(GL_BLEND); + glDisable(GL_LINE_SMOOTH); /* disable line antialiasing */ + + /* + glEnable(GL_DEPTH_TEST); + glDepthMask(GL_TRUE); + */ +} + +/* + drawTrailShadow() draws a alpha-blended shadow on the floor for each + trail segment. + The light source source is (in homogenous coordinates) + at (-1,-1,1,0) (I hope that's correct) +*/ + +void drawTrailShadow(Player* p, PlayerVisual *pV) { + /* states */ + + if(gSettingsCache.use_stencil) { + glEnable(GL_STENCIL_TEST); + glStencilOp(GL_REPLACE, GL_REPLACE, GL_REPLACE); + glStencilFunc(GL_GREATER, 1, 1); + glEnable(GL_BLEND); + glColor4fv(shadow_color); + glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); + } else { + glColor3f(0, 0, 0); + glDisable(GL_BLEND); + } + + /* transformation */ + + glPushMatrix(); + glMultMatrixf(shadow_matrix); + + /* geometry */ + { + int vOffset = 0; + int iOffset = 0; + + TrailMesh mesh; + mesh.pVertices = (vec3*) malloc(1000 * sizeof(vec3)); + mesh.pNormals = (vec3*) malloc(1000 * sizeof(vec3)); + mesh.pColors = (unsigned char*) malloc(1000 * 4 * sizeof(float)); + mesh.pTexCoords = (vec2*) malloc(1000 * sizeof(vec2)); + mesh.pIndices = (unsigned short*) malloc(1000 * 2); + mesh.iUsed = 0; + + trailGeometry(p, pV, &mesh, &vOffset, &iOffset); + bowGeometry(p, pV, &mesh, &vOffset, &iOffset); + trailStatesShadowed(); + trailRender(&mesh); + // no states restore, because we're drawing shadowed geometry + + free(mesh.pVertices); + free(mesh.pNormals); + free(mesh.pColors); + free(mesh.pTexCoords); + free(mesh.pIndices); + } + + /* restore */ + + if(gSettingsCache.use_stencil) + glDisable(GL_STENCIL_TEST); + + glDisable(GL_BLEND); + + glPopMatrix(); +} + |