ShadowMaps + 2 Lights (or more) + glsl1.2 = Trouble - opengl

Question

Well, I've done a test to see if it works the shadowmapping using two light source. Something is wrong, the first shadowmap make a correct shade, but the second shadowmap not. This is the complete code.
FUNCTIONS
void setupMatrices(float position_x,float position_y,float position_z,float lookAt_x,float lookAt_y,float lookAt_z){
glLoadIdentity();
gluLookAt(position_x,position_y,position_z,lookAt_x,lookAt_y,lookAt_z,0,1,0);
}
void setTextureMatrix1(){
static double modelView[16];
static double projection[16];
const GLdouble bias[16] = {0.5, 0.0, 0.0, 0.0,
0.0, 0.5, 0.0, 0.0,
0.0, 0.0, 0.5, 0.0,
0.5, 0.5, 0.5, 1.0};
glGetDoublev(GL_MODELVIEW_MATRIX, modelView);
glGetDoublev(GL_PROJECTION_MATRIX, projection);
glMatrixMode(GL_TEXTURE);
glActiveTexture(GL_TEXTURE6);
glLoadIdentity();
glLoadMatrixd(bias);
glMultMatrixd (projection);
glMultMatrixd (modelView);
glMatrixMode(GL_MODELVIEW);
}
void setTextureMatrix2(){
static double modelView[16];
static double projection[16];
const GLdouble bias[16] = {0.5, 0.0, 0.0, 0.0,
0.0, 0.5, 0.0, 0.0,
0.0, 0.0, 0.5, 0.0,
0.5, 0.5, 0.5, 1.0};
glGetDoublev(GL_MODELVIEW_MATRIX, modelView);
glGetDoublev(GL_PROJECTION_MATRIX, projection);
glMatrixMode(GL_TEXTURE);
glActiveTexture(GL_TEXTURE7);
glLoadIdentity();
glLoadMatrixd(bias);
glMultMatrixd (projection);
glMultMatrixd (modelView);
glMatrixMode(GL_MODELVIEW);
}
void startTranslate1(float x,float y,float z){
glPushMatrix();
glTranslatef(x,y,z);
glMatrixMode(GL_TEXTURE);
glActiveTextureARB(GL_TEXTURE6);
glPushMatrix();
glTranslatef(x,y,z);
}
void startTranslate2(float x,float y,float z){
glPushMatrix();
glTranslatef(x,y,z);
glMatrixMode(GL_TEXTURE);
glActiveTextureARB(GL_TEXTURE7);
glPushMatrix();
glTranslatef(x,y,z);
}
void endTranslate(){
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
glPopMatrix();
}
void drawObjects1(){
glColor4f(0.3f,0.3f,0.3f,1);
glBegin(GL_QUADS);
glVertex3f(-35,2,-35);
glVertex3f(-35,2, 15);
glVertex3f( 15,2, 15);
glVertex3f( 15,2,-35);
glEnd();
glColor4f(0.9f,0.9f,0.9f,1);
startTranslate1(0,4,-5);
glutSolidCube(4);
endTranslate();
}
void drawObjects2(){
glColor4f(0.3f,0.3f,0.3f,1);
glBegin(GL_QUADS);
glVertex3f(-35,2,-35);
glVertex3f(-35,2, 15);
glVertex3f( 15,2, 15);
glVertex3f( 15,2,-35);
glEnd();
glColor4f(0.9f,0.9f,0.9f,1);
startTranslate2(0,4,-5);
glutSolidCube(4);
endTranslate();
}
MAIN
int main(){
GLuint depthTextureId;
glGenTextures(1, &depthTextureId);
glBindTexture(GL_TEXTURE_2D, depthTextureId);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP );
glTexImage2D( GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, shadowMapWidth, shadowMapHeight, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, 0);
glBindTexture(GL_TEXTURE_2D, 0);
GLuint fboId;
GLenum FBOstatus;
glGenFramebuffersEXT(1, &fboId);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fboId);
glDrawBuffer(GL_NONE);
glReadBuffer(GL_NONE);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,GL_TEXTURE_2D, depthTextureId, 0);
FBOstatus = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
if(FBOstatus != GL_FRAMEBUFFER_COMPLETE_EXT)return 1;
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
/////////////////////////////////////////////////////////////////////
GLuint depthTextureId2;
glGenTextures(1, &depthTextureId2);
glBindTexture(GL_TEXTURE_2D, depthTextureId2);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP );
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP );
glTexImage2D( GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, shadowMapWidth, shadowMapHeight, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, 0);
glBindTexture(GL_TEXTURE_2D, 0);
GLuint fboId2;
GLenum FBOstatus2;
glGenFramebuffersEXT(1, &fboId2);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fboId2);
glDrawBuffer(GL_NONE);
glReadBuffer(GL_NONE);
glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,GL_TEXTURE_2D, depthTextureId2, 0);
FBOstatus2 = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
if(FBOstatus2 != GL_FRAMEBUFFER_COMPLETE_EXT)return 1;
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
GLfloat angulo = 0.0;
GLfloat posZ = 0.0;
glEnable(GL_CULL_FACE);
glHint(GL_PERSPECTIVE_CORRECTION_HINT,GL_NICEST);
MAIN LOOP
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT,fboId);
glViewport(0,0,640,480);
glClear(GL_DEPTH_BUFFER_BIT);
glColorMask(GL_FALSE,GL_FALSE,GL_FALSE,GL_FALSE);
setupMatrices(5.0,15.0,0.0,-5.0,0.0,-5.0);
glCullFace(GL_FRONT);
drawObjects1();
setTextureMatrix1();
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT,0);
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT,fboId2);
glViewport(0,0,640,480);
glClear(GL_DEPTH_BUFFER_BIT);
glColorMask(GL_FALSE,GL_FALSE,GL_FALSE,GL_FALSE);
setupMatrices(p_light[0],p_light[1],p_light[2],l_light[0],l_light[1],l_light[2]);
glCullFace(GL_FRONT);
drawObjects2();
setTextureMatrix2();
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT,0);
glViewport(0,0,640,480);
glColorMask(GL_TRUE,GL_TRUE,GL_TRUE,GL_TRUE);
glUseProgram(p);
glUniform1i(shadowMapUniform,6);
glActiveTexture(GL_TEXTURE6);
glBindTexture(GL_TEXTURE_2D,depthTextureId);
glUniform1i(shadowMapUniform2,7);
glActiveTexture(GL_TEXTURE7);
glBindTexture(GL_TEXTURE_2D,depthTextureId2);
glCullFace(GL_BACK);
setupMatrices(p_camera[0],p_camera[1],p_camera[2],l_camera[0],l_camera[1],l_camera[2]);
drawObjects1();
glBindTexture(GL_TEXTURE_2D,0);
glUseProgram(0);
VERTEX SHADER
varying vec4 ShadowCoord1;
varying vec4 ShadowCoord2;
void main(){
ShadowCoord1 = gl_TextureMatrix[6] * gl_Vertex;
ShadowCoord2 = gl_TextureMatrix[7] * gl_Vertex;
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
gl_FrontColor = gl_Color;
}
FRAGMENT SHADER
uniform sampler2D ShadowMap;
uniform sampler2D ShadowMap2;
varying vec4 ShadowCoord1;
varying vec4 ShadowCoord2;
varying vec3 pvertice;
void main(){
vec4 shadowCoordinateWdivide1 = ShadowCoord1 / ShadowCoord1.w ;
vec4 shadowCoordinateWdivide2 = ShadowCoord2 / ShadowCoord2.w ;
shadowCoordinateWdivide1.z += 0.0001;
shadowCoordinateWdivide2.z += 0.0001;
float distanceFromLight1 = texture2D(ShadowMap,shadowCoordinateWdivide1.st).z;
float distanceFromLight2 = texture2D(ShadowMap2,shadowCoordinateWdivide2.st).z;
float shadow1 = 1.0;
if (ShadowCoord1.w > 0.0){
shadow1 = distanceFromLight1 < shadowCoordinateWdivide1.z ? 0.5 : 1.0 ;
}
float shadow2 = 1.0;
if (ShadowCoord2.w > 0.0){
shadow2 = distanceFromLight2 < shadowCoordinateWdivide2.z ? 0.5 : 1.0 ;
}
gl_FragColor = mix(shadow1,shadow2,0.5) * gl_Color;
}
What is wrong? This looks like...
If I try to move around the object it looks bad.
While with a single light in the same position it looks like this.
If I try to move around the object this looks good.
Thanks.

Answer 1

Those bias impact self shadowing, try setting them a bit higher.
shadowCoordinateWdivide1.z += 0.0001;
shadowCoordinateWdivide2.z += 0.0001;