(OpenGL ShadowMap)Shadow cast on incorrect faces - opengl

Question

Here is the demo image:
(Left top 256x256 rect is the depth texture)
I render the shadow map in the first pass(with parallel projection),
then render the scene in the second pass,
then render the scene with shadow map in the final pass.
the shadow is sometimes rendered twice or on the wrong surfaces
Is there any solution?
Full code here:
typedef struct
{
vec3_t org;//origin
vec3_t off;//position offset
vec3_t ang;//angle
float dist;//radius
int w;//default 512
int h;//default 512
int depth;//depth texture
int color;//color texture
int dimension;//default = 8
float mvmatrix[16];
float projmatrix[16];
cl_entity_t *followent;
int inuse;
}sdlight_t;
void R_RenderDepthMap()
{
qglPolygonOffset( 5.0, 0.0 );
qglEnable(GL_POLYGON_OFFSET_FILL);
if(cursdlight->followent)
{
VectorCopy(cursdlight->followent->origin, cursdlight->org);
}
qglMatrixMode(GL_PROJECTION);
qglLoadIdentity();
qglOrtho(-cursdlight->w / cursdlight->dimension, cursdlight->w / cursdlight->dimension, -cursdlight->h / cursdlight->dimension, cursdlight->h / cursdlight->dimension, -9999, 9999);//cursdlight->dist
qglMatrixMode(GL_MODELVIEW);
qglLoadIdentity();
qglRotatef(-90, 1, 0, 0);
qglRotatef(90, 0, 0, 1);
qglRotatef(-cursdlight->ang[2], 1, 0, 0);
qglRotatef(-cursdlight->ang[0], 0, 1, 0);
qglRotatef(-cursdlight->ang[1], 0, 0, 1);
qglTranslatef(-cursdlight->org[0], -cursdlight->org[1], -cursdlight->org[2]);
qglViewport(0, 0, cursdlight->w, cursdlight->h);
glGetFloatv(GL_PROJECTION_MATRIX, cursdlight->projmatrix);
glGetFloatv(GL_MODELVIEW_MATRIX, cursdlight->mvmatrix);
qglDepthRange(1.0, 0.0);
qglDepthFunc(GL_LEQUAL);
qglEnable(GL_CULL_FACE);
//qglCullFace(GL_FRONT);
qglClearColor(1, 1, 1, 1);
qglClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
//Render Models..
R_DrawEntitiesOnList();
qglDisable(GL_POLYGON_OFFSET_FILL);
qglBindFramebufferEXT(GL_READ_FRAMEBUFFER, s_BackBufferFBO.s_hBackBufferFBO);
qglActiveTextureARB(GL_TEXTURE0);
qglBindTexture(GL_TEXTURE_2D, cursdlight->depth);
qglCopyTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT24, 0, 0, cursdlight->w, cursdlight->h, 0);
}
void R_SetupShadowLight(void)
{
// enable automatic texture coordinates generation
GLfloat planeS[] = {1.0, 0.0, 0.0, 0.0};
GLfloat planeT[] = {0.0, 1.0, 0.0, 0.0};
GLfloat planeR[] = {0.0, 0.0, 1.0, 0.0};
GLfloat planeQ[] = {0.0, 0.0, 0.0, 1.0};
// setup texture stages
qglActiveTextureARB(GL_TEXTURE0_ARB);
qglBindTexture(GL_TEXTURE_2D, cursdlight->depth);
qglTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
qglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE_ARB, GL_COMPARE_REF_TO_TEXTURE);
qglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_FUNC_ARB, GL_LEQUAL);
qglTexParameteri(GL_TEXTURE_2D, GL_DEPTH_TEXTURE_MODE_ARB, GL_INTENSITY);
qglEnable(GL_TEXTURE_GEN_S);
qglEnable(GL_TEXTURE_GEN_T);
qglEnable(GL_TEXTURE_GEN_R);
qglEnable(GL_TEXTURE_GEN_Q);
qglTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
qglTexGenfv(GL_S, GL_EYE_PLANE, planeS);
qglTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
qglTexGenfv(GL_T, GL_EYE_PLANE, planeT);
qglTexGeni(GL_R, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
qglTexGenfv(GL_R, GL_EYE_PLANE, planeR);
qglTexGeni(GL_Q, GL_TEXTURE_GEN_MODE, GL_EYE_LINEAR);
qglTexGenfv(GL_Q, GL_EYE_PLANE, planeQ);
// load texture projection matrix
qglMatrixMode(GL_TEXTURE);
qglLoadIdentity();
qglTranslatef(0.5, 0.5, 0.5);
qglScalef(0.5, 0.5, 0.5);
qglMultMatrixf(cursdlight->projmatrix);
qglMultMatrixf(cursdlight->mvmatrix);
qglMatrixMode(GL_MODELVIEW);
if (gl_polyoffset->value)
{
qglEnable(GL_POLYGON_OFFSET_FILL);
qglPolygonOffset(-1, -gl_polyoffset->value);
}
qglDepthMask(GL_FALSE);
qglEnable(GL_BLEND);
qglBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
qglColor4f(1,1,1,1);
qglUseProgramObjectARB(shadow_program);
qglUniform1iARB(shadow_uniform.shadowmap, 0);
}
void R_FinishShadowLight(void)
{
qglUseProgramObjectARB(0);
if (gl_polyoffset->value)
{
qglDisable(GL_POLYGON_OFFSET_FILL);
}
qglDepthMask(GL_TRUE);
qglDisable(GL_BLEND);
qglActiveTextureARB(GL_TEXTURE0_ARB);
qglTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_COMPARE_MODE_ARB, GL_NONE);
qglMatrixMode(GL_TEXTURE);
qglLoadIdentity();
qglDisable(GL_TEXTURE_GEN_S);
qglDisable(GL_TEXTURE_GEN_T);
qglDisable(GL_TEXTURE_GEN_R);
qglDisable(GL_TEXTURE_GEN_Q);
qglMatrixMode(GL_MODELVIEW);
}
void R_DrawShadows(void)
{
for (int i = 0; i < numsdlights; i++)
{
cursdlight = &sdlights[i];
if(!R_ShouldCastShadow())
continue;
R_SetupShadowLight();
R_DrawSceneShadow();
R_FinishShadowLight();
}
}
GLSL part:
//vertex shader
varying vec4 shadowcoord;
void main()
{
shadowcoord = gl_TextureMatrix[0] * gl_Vertex;
gl_Position = ftransform();
}
//fragment shader
#version 120
uniform sampler2DShadow shadowmap;
varying vec4 shadowcoord;
uniform float xoffset = 1.0/512.0;
uniform float yoffset = 1.0/512.0;
float lookup(vec4 coord, vec2 offSet)
{
return shadow2DProj(shadowmap, coord + vec4(offSet.x * xoffset, offSet.y * yoffset, 0.0, 0.0) ).w;
}
void main()
{
float shadow;
shadow = lookup(shadowcoord, vec2(0.0,0.0)) + lookup(shadowcoord, vec2(0.035,0.0)) + lookup(shadowcoord, vec2(-0.035,0.0)) + lookup(shadowcoord, vec2(0.0,0.035)) + lookup(shadowcoord, vec2(0.0,-0.035));
shadow /= 5.0;
if(shadow == 1.0)
discard;
else
gl_FragColor = vec4(0.0, 0.0, 0.0, (1.0-shadow) * 0.5);
}