Textures in CG. What am I doing wrong?

102

Author

August 03, 2008 05:08 AM

I've gotten all the really basic stuff to work but I can't figure out how to load a texture into my shader. I'm going to post the code and I hope one of you can tell me what I'm doing wrong. Also if you see anything else in the code that you think needs to be fixed please tell me. Here is the code: Shader:



struct VS_INPUT
{
	float4 position : POSITION;
	float4 color	: COLOR0;
};

struct VS_OUTPUT
{
	float4 position : POSITION;
	float4 color	: COLOR0;
};

VS_OUTPUT VS(VS_INPUT IN, uniform float4x4 ModelViewProj)
{
	VS_OUTPUT OUT;
	OUT.position = mul(ModelViewProj, IN.position);
	OUT.color = IN.color;
	return OUT;
}

float4 PS(VS_OUTPUT IN, uniform sampler2D Tex0) : COLOR
{
	return tex2D( Tex0, IN.position.xy );
}

Probably this code is the problem:



GLuint LoadTextureRAW( const char * filename, int wrap )
{
    GLuint texture;
    int width, height;
    BYTE * data;
    FILE * file;
    file = fopen( filename, "rb" );
    if ( file == NULL ) return 0;
    width = 256;
    height = 256;
    data = new BYTE[width * height * 3];
    fread( data, width * height * 3, 1, file );
    fclose( file );
    glGenTextures( 1, &texture );
    glBindTexture( GL_TEXTURE_2D, texture );
    glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,wrap ? GL_REPEAT : GL_CLAMP );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,wrap ? GL_REPEAT : GL_CLAMP );
    gluBuild2DMipmaps( GL_TEXTURE_2D, 3, width, height,GL_RGB, GL_UNSIGNED_BYTE, data );
    delete [] data;
    return texture;
}


void render()
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();
	gluLookAt(0.0f, 25.0f, -45.0f, 0.0f, 0.0f, 0.0f, 0, 1, 0);
	cgGLSetStateMatrixParameter(modelViewMatrix, CG_GL_MODELVIEW_PROJECTION_MATRIX, CG_GL_MATRIX_IDENTITY);
	cgGLSetTextureParameter( Tex0, texture[0] );
	cgGLEnableProfile(cgVertexProfile);
	cgGLBindProgram(cg_vs);
	cgGLEnableProfile(cgPixelProfile);
	cgGLBindProgram(cg_ps);
	cgGLEnableTextureParameter( Tex0 );
	glEnableClientState( GL_VERTEX_ARRAY );
	glBindBuffer( GL_ARRAY_BUFFER, vertex_buffer );
	glVertexPointer( 3, GL_FLOAT, 0, 0);
	glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, index_buffer );
	glDrawElements(GL_TRIANGLES,3,GL_UNSIGNED_SHORT,0);
	glDisableClientState( GL_VERTEX_ARRAY );
	cgGLDisableTextureParameter( Tex0 );
	cgGLDisableProfile(cgPixelProfile);
	cgGLDisableProfile(cgVertexProfile);
	SwapBuffers(hDC);
}

Full Application:


#include <windows.h>
#include <stdio.h>
#include <gl\glew.h>
#include <gl\gl.h>
#include <gl\glu.h>
#include <cg\cg.h>
#include <cg\cgGL.h>

HWND            hWnd=NULL;
HGLRC           hRC=NULL;
HDC             hDC=NULL;

bool	keys[256];

CGcontext	 cgContext;
CGprogram	 cg_vs, cg_ps;
CGprofile	 cgVertexProfile, cgPixelProfile;
CGparameter	 position, color, modelViewMatrix;
CGparameter  Tex0;
GLuint       vertex_buffer, index_buffer;
GLuint		 texture[1];

class CVert
{
public:
	float x;
	float y;
	float z;
};

LRESULT	CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

GLvoid GLResize(GLsizei width, GLsizei height)
{
	if(height==0)
		height=1;
	glViewport(0,0,width,height);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(45.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
}

GLuint LoadTextureRAW( const char * filename, int wrap )
{
    GLuint texture;
    int width, height;
    BYTE * data;
    FILE * file;

    file = fopen( filename, "rb" );
    if ( file == NULL ) return 0;
    width = 256;
    height = 256;
    data = new BYTE[width * height * 3];
    fread( data, width * height * 3, 1, file );
    fclose( file );
    glGenTextures( 1, &texture );
    glBindTexture( GL_TEXTURE_2D, texture );
    glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S,wrap ? GL_REPEAT : GL_CLAMP );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T,wrap ? GL_REPEAT : GL_CLAMP );
    gluBuild2DMipmaps( GL_TEXTURE_2D, 3, width, height,GL_RGB, GL_UNSIGNED_BYTE, data );
    delete [] data;

    return texture;
}

void load_mesh()
{
	CVert* vertices = new CVert[3];
	vertices[0].x=0;
	vertices[0].y=0;
	vertices[0].z=0;
	vertices[1].x=10;
	vertices[1].y=0;
	vertices[1].z=0;
	vertices[2].x=0;
	vertices[2].y=10;
	vertices[2].z=0;
	int* indices = new int[3];
	indices[0]=2;
	indices[1]=1;
	indices[2]=0;
	glGenBuffers( 1, &vertex_buffer );
	glBindBuffer( GL_ARRAY_BUFFER, vertex_buffer );
	glBufferData( GL_ARRAY_BUFFER, 9*sizeof(float), vertices, GL_STATIC_DRAW );
	glGenBuffers( 1, &index_buffer );
	glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, index_buffer );
	glBufferData( GL_ELEMENT_ARRAY_BUFFER, 3*sizeof(int), indices, GL_STATIC_DRAW );
	delete [] vertices;
	delete [] indices;
}

void render()
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();
	gluLookAt(0.0f, 25.0f, -45.0f, 0.0f, 0.0f, 0.0f, 0, 1, 0);
	cgGLSetStateMatrixParameter(modelViewMatrix, CG_GL_MODELVIEW_PROJECTION_MATRIX, CG_GL_MATRIX_IDENTITY);

    cgGLSetTextureParameter( Tex0, texture[0] );

	cgGLEnableProfile(cgVertexProfile);
	cgGLBindProgram(cg_vs);
	cgGLEnableProfile(cgPixelProfile);
	cgGLBindProgram(cg_ps);

	cgGLEnableTextureParameter( Tex0 );

	glEnableClientState( GL_VERTEX_ARRAY );
	glBindBuffer( GL_ARRAY_BUFFER, vertex_buffer );
	glVertexPointer( 3, GL_FLOAT, 0, 0);
	glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, index_buffer );
	glDrawElements(GL_TRIANGLES,3,GL_UNSIGNED_SHORT,0);
	glDisableClientState( GL_VERTEX_ARRAY );



	cgGLDisableTextureParameter( Tex0 );

	cgGLDisableProfile(cgPixelProfile);
	cgGLDisableProfile(cgVertexProfile);
	SwapBuffers(hDC);
}

LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
	switch (uMsg)
	{
		case WM_CLOSE:
		{
			PostQuitMessage(0);
			return 0;
		}
		case WM_KEYDOWN:
		{
			keys[wParam] = TRUE;
			return 0;
		}
		case WM_KEYUP:
		{
			keys[wParam] = FALSE;
			return 0;
		}
		case WM_CREATE:
		{
			GLResize(LOWORD(lParam),HIWORD(lParam));
			return 0;
		}
		case WM_SIZE:
		{
			GLResize(LOWORD(lParam),HIWORD(lParam));
			return 0;
		}
	}
	return DefWindowProc(hWnd,uMsg,wParam,lParam);
}

int WINAPI WinMain(	HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow )
{
	RECT		WindowRect;
	WindowRect.left=0;
	WindowRect.right=640;
	WindowRect.top=0;
	WindowRect.bottom=480;	
	WNDCLASS	wc;
	wc.style			= CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
	wc.lpfnWndProc		= (WNDPROC) WndProc;
	wc.cbClsExtra		= 0;
	wc.cbWndExtra		= 0;
	wc.hInstance		= 0;
	wc.hIcon			= LoadIcon(NULL, IDI_WINLOGO);
	wc.hCursor			= LoadCursor(NULL, IDC_ARROW);
	wc.hbrBackground	= 0;
	wc.lpszMenuName		= 0;
	wc.lpszClassName	= "Debug";
	RegisterClass(&wc);
	hWnd = CreateWindowEx( WS_EX_APPWINDOW  | WS_EX_WINDOWEDGE, "Debug",
 	"Debug" ,WS_OVERLAPPEDWINDOW | WS_CLIPSIBLINGS | WS_CLIPCHILDREN,
 	WindowRect.left, WindowRect.top, WindowRect.right-WindowRect.left,
 	WindowRect.bottom-WindowRect.top, 0, 0, 0, 0);
	ShowWindow(hWnd,SW_SHOW);
	UnregisterClass( "Debug", wc.hInstance );
	static PIXELFORMATDESCRIPTOR pfd={ sizeof(PIXELFORMATDESCRIPTOR), 1,
 	PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL |PFD_DOUBLEBUFFER,PFD_TYPE_RGBA, 16,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16, 0, 0, PFD_MAIN_PLANE, 0, 0, 0, 0 };
	hDC=GetDC(hWnd);
	SetPixelFormat(hDC,ChoosePixelFormat(hDC,&pfd),&pfd);
	hRC = wglCreateContext(hDC);
	wglMakeCurrent(hDC,hRC);
	glShadeModel(GL_SMOOTH);
	glClearColor(1.0f, 0.0f, 0.0f, 0.0f);
	glClearDepth(1.0f);
	glEnable(GL_DEPTH_TEST);
	glDepthFunc(GL_LEQUAL);
	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
	cgContext = cgCreateContext();
	cgVertexProfile = cgGLGetLatestProfile(CG_GL_VERTEX);
	cgPixelProfile = cgGLGetLatestProfile(CG_GL_FRAGMENT);
	cg_vs = cgCreateProgramFromFile(cgContext, CG_SOURCE, "Data/Shaders/default.cg", cgVertexProfile, "VS", 0);
	cgGLLoadProgram(cg_vs);
	cg_ps = cgCreateProgramFromFile(cgContext, CG_SOURCE, "Data/Shaders/default.cg", cgPixelProfile, "PS", 0);
	cgGLLoadProgram(cg_ps);
	position		= cgGetNamedParameter(cg_vs, "IN.position");
	color			= cgGetNamedParameter(cg_vs, "IN.color");
	modelViewMatrix	= cgGetNamedParameter(cg_vs, "ModelViewProj");
	Tex0            = cgGetNamedParameter(cg_ps, "Tex0");
	GLResize(WindowRect.right-WindowRect.left, WindowRect.bottom-WindowRect.top);
	glewInit();
	load_mesh();

	texture[0]=LoadTextureRAW( "u.raw", 0 );

	MSG msg;
	ZeroMemory( &msg, sizeof( msg ) );
	while( msg.message!=WM_QUIT )
	{
		if( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) )
		{
			TranslateMessage( &msg );
			DispatchMessage( &msg );
		}
		else
			render();
	}
	wglMakeCurrent(NULL,NULL);
	wglDeleteContext(hRC);
	hRC=NULL;
	return (msg.wParam);
}

[Edited by - EmptyVoid on August 3, 2008 11:36:51 AM]

This is your life, and it's ending one minute at a time. - Fight club

superpig

1,826

August 03, 2008 11:45 AM

What happens when you run the code currently?

Richard "Superpig" Fine - saving pigs from untimely fates - Microsoft DirectX MVP 2006/2007/2008/2009
"Shaders are not meant to do everything. Of course you can try to use it for everything, but it's like playing football using cabbage." - MickeyMouse

EmptyVoid

102

Author

August 03, 2008 01:54 PM

Quote:Original post by superpig
What happens when you run the code currently?

Big empty window and no triangle any where to be found.

[Edited by - EmptyVoid on August 3, 2008 3:54:07 PM]

This is your life, and it's ending one minute at a time. - Fight club

EmptyVoid

102

Author

August 03, 2008 03:01 PM

Also when I change the shader to just output the color like this:

[source c++]struct VS_INPUT{	float4 position : POSITION;	float4 color	: COLOR0;};struct VS_OUTPUT{	float4 position : POSITION;	float4 color	: COLOR0;};VS_OUTPUT VS(VS_INPUT IN, uniform float4x4 ModelViewProj){	VS_OUTPUT OUT;	OUT.position = mul(ModelViewProj, IN.position);	OUT.color = IN.color;	return OUT;}float4 PS(VS_OUTPUT IN, uniform sampler2D Tex0) : COLOR{	return IN.color.xyzw;}

It then works fine but no texture...

This is your life, and it's ending one minute at a time. - Fight club

nullsquared

128

August 03, 2008 03:43 PM

I'm pretty sure you can't get the POSITION binding into a pixel shader. Pass down TEXCOORD0 from the vertex shader to the pixel shader, and use that.

www.nullular.com

hlsl

100

August 03, 2008 03:44 PM

Not sure but I think you need to output texture coordinates from vertex shader like this:

//------------------------------------------------------------------------------------------------------struct VS_INPUT{    float4 pos : POSITION;    float2 tc : TEXCOORD0;};//------------------------------------------------------------------------------------------------------struct VS_OUTPUT{    float4 pos : POSITION;    float2 tc : TEXCOORD0;};//------------------------------------------------------------------------------------------------------VS_OUTPUT VS(VS_INPUT In){    VS_OUTPUT Out = (VS_OUTPUT)0;	    Out.pos = mul(In.pos, matWorldViewProj);    Out.tc = In.tc;    return Out;}

EmptyVoid

102

Author

August 03, 2008 09:28 PM

Quote:Original post by agi_shi
I'm pretty sure you can't get the POSITION binding into a pixel shader. Pass down TEXCOORD0 from the vertex shader to the pixel shader, and use that.

*Face palm* I probably would have noticed that if I was using HLSL. Ok seems to work now.

This is your life, and it's ending one minute at a time. - Fight club

Textures in CG. What am I doing wrong?

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Textures in CG. What am I doing wrong?

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