• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
NimrodPSI

OpenGL
OpenGL 3.2+ and GLSL texturing

7 posts in this topic

Hello all, I have recently begun the switch from old OpenGL to the newer specification that uses VAO's and VBO's for like... everything.
I am having alot of trouble getting texturing to work with GLSL and my VAO's, I managed to get lighting and color with GLSL working earlier(using an individuale VBO for ther verts, color, and normals) so i know my view/projection/model matrixies are all okay. I manually generate all the verticies of a cube into v[108] (im not using TRIAGLE_STRIPS right now so its 2 tri's a side) and then the tex coords for each vertex into t[72]. Since each vertex of 3 floats only requires two tex coords right? Might be useful to know im going off Swiftless's OpenGL 4 GLSL tutorials so I'm using glm and glew.

Also I use glBindAttribute to always pass the vertices position as a vec3 and to pass the tex coords as a vec2 into my Shader program(the same way i passed verts, color and normals earlier)

Any way heres some code:

This generates my VAO from 2 VBO's, one fro my verts and the other tex coords.
[code]glGenVertexArrays(1, &vaoID);
glBindVertexArray(vaoID);

glGenBuffers(2, &vboID[0]);
//Verticies
glBindBuffer(GL_ARRAY_BUFFER, vboID[0]);
glBufferData(GL_ARRAY_BUFFER, 108 * sizeof(GLfloat), v, GL_STATIC_DRAW);
glVertexAttribPointer((GLuint)0, 3, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(0);
//Tex Coords
glBindBuffer(GL_ARRAY_BUFFER, vboID[1]);
glBufferData(GL_ARRAY_BUFFER, 72 * sizeof(GLfloat), t, GL_STATIC_DRAW);
glVertexAttribPointer((GLuint)1, 2, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(1);

glBindVertexArray(0);[/code]

Then I draw the cube like so:
[code]
shader->bind();
int projectionMatrixLocation = glGetUniformLocation(shader->id(), "projectionMatrix");
int viewMatrixLocation = glGetUniformLocation(shader->id(), "viewMatrix");
int modelMatrixLocation = glGetUniformLocation(shader->id(), "modelMatrix");
int texture_location = glGetUniformLocation(shader->id(), "texture_color");

glUniformMatrix4fv(projectionMatrixLocation, 1, GL_FALSE, &projectionMatrix[0][0]);
glUniformMatrix4fv(viewMatrixLocation, 1, GL_FALSE, &viewMatrix[0][0]);
glUniformMatrix4fv(modelMatrixLocation, 1, GL_FALSE, &modelMatrix[0][0]);

glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture[0]);
glUniform1i(texture_location, 0);


glBindVertexArray(vaoID);
glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(0);


shader->unbind();
[/code]

...and my Vertex and Pixel(fragment) shaders respectivley:
[code]
#version 150 core

uniform mat4 projectionMatrix;
uniform mat4 viewMatrix;
uniform mat4 modelMatrix;

in vec3 in_Position;
in vec2 in_TexCoord;

void main(void){
gl_TexCoord[0] = in_TexCoord;

gl_Position = projectionMatrix * viewMatrix * modelMatrix * vec4(in_Position, 1.0);
}
[/code]

[code]
#version 150 core

uniform sampler2D texture_color;

void main(void){
gl_FragColor = texture2D(texture_color, gl_TexCoord[0].st);

}
[/code]
The result is a white cube that seems to lose its scaleing compared to when I specify a solid gl_FragColor

My assumtion is something to do with gl_TexCoord[0] not being a vec2 like in_TexCoord but I can't seem to find much/any documentaion on GLSL when using custom arrays for everything. All the examples I've seen use gl_MultiTexCoord[0] to pull the tex coords from the now depriciated glMultiTexCoordxx()... I think [img]http://public.gamedev.net//public/style_emoticons/default/happy.png[/img].
I can post the vertex and tex coords initialization routine if that would help but its alot of crap lol.
I apologize if I'm not giving enough info or too much lol. I greatly appreciate any help given!!
0

Share this post


Link to post
Share on other sites
I'm not sure about the gl_TexCoord[0] issue, but I would suggest just to define your own varying texcoord variable and not use the builtin one. Are you checking shaders and programs for compile errors?

You said you're using glBindAttribute, do you mean glBindAttribLocation?
0

Share this post


Link to post
Share on other sites
If you read Swiftless, he says:

[quote]In GLSL 1.50, we no longer have gl_ModelViewMatrix, gl_ProjectionMatrix, gl_Vertex, etc, etc[/quote] So it appears you cannot use the built-in texture coordinate array. Declare your own varying vec2 variable, set it to the attribute texture coordinate in the vertex shader, and feed it to the fragment shader. Also, don't use the built-in fragment color variable. Declare your own vec4. Something like this:


[code]
#version 150 core

uniform mat4 projectionMatrix;
uniform mat4 viewMatrix;
uniform mat4 modelMatrix;

in vec3 in_Position;
in vec2 in_TexCoord;


out vec2 out_TexCoord;


void main(void){
out_TexCoord = in_TexCoord;

gl_Position = projectionMatrix * viewMatrix * modelMatrix * vec4(in_Position, 1.0);
}


[/code]




[code]
#version 150 core

in vec2 out_TexCoord;
uniform sampler2D texture_color;
out vec4 FragColor;

void main(void){
FragColor = texture2D(texture_color, out_TexCoord.st);

}[/code]

If that doesn't work, check the stuff that Karwosts mentioned above.
1

Share this post


Link to post
Share on other sites
@karwosts - Yes I meant glBindAttribLocation, sorry I had literally been up all night working with the new GL specification and It was starting to hurt my brain lol.

Okay I dropped the usage of gl_TexCoord[0] and did as Jesse7 suggested but that still didn't work, although not because it's incorrect. The issue seems to be the texture loader I have been using all the time from all my intermediate mode stuff. Not sure what was wrong with it but replaceing it with Swiftless's RAW texture loader code and doing the things Jesse7 suggested worked like a charm. It may be worth noteing that in the fragment shader the line:
[code]FragColor = texture2D(texture_color, out_TexCoord.st); [/code]

You don't need the .st at the end of our varying vec2 out_TexCoord, or at least it works without it. What is the purpose of the .st at the end of a vec2 varialbe?
Anyways I hate the RAW format so I guess it's time to write my own Targa loader.
Thank you all for your help! ^_^
0

Share this post


Link to post
Share on other sites
[quote name='NimrodPSI' timestamp='1329868338' post='4915325']
What is the purpose of the .st at the end of a vec2 varialbe?
Anyways I hate the RAW format so I guess it's time to write my own Targa loader.
[/quote] I guess .st is redundant since we have a vec2. For loading Targas and a slew of other formats, you could use FreeImage or DevIL. SOIL is another one but it doesn't seem to work with a core profile.
0

Share this post


Link to post
Share on other sites
Well I had been using a pretty good Targa loader for a while and had even adapted the code to load my own height maps. Although I now have figured out why my texture loader wasn't working In the first place. I tried replaceing the filtering on the RAW texture loader to use mipmaps and used gluBuild2DMipmaps(); but as soon as I ran it resulted in the same black cube. So my old texture loader that also used mipmaps was wrong due to this. I've looked around a bit about GLSL mipmaping and found the command texture2dLod(); So I'm going to persue that route at some point.
0

Share this post


Link to post
Share on other sites
[quote name='NimrodPSI' timestamp='1329949496' post='4915691']
I tried replaceing the filtering on the RAW texture loader to use mipmaps and used gluBuild2DMipmaps(); but as soon as I ran it resulted in the same black cube. So my old texture loader that also used mipmaps was wrong due to this. I've looked around a bit about GLSL mipmaping and found the command texture2dLod(); So I'm going to persue that route at some point.
[/quote] Yeah, if you use deprecated code with a core profile you sometimes get weird stuff like black textures [img]http://public.gamedev.net//public/style_emoticons/default/blink.png[/img]. I don't much about that GLSL command, but another way of generating mipmaps is by calling glGenerateMipmap () right after you load the texture:
[code]

// use trilinear filtering
glBindTexture(GL_TEXTURE_2D, textureId);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER, GL_LINEAR );
glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA, w, h, 0, GL_RGBA,GL_UNSIGNED_BYTE,pixels);

// generate mipmaps
glGenerateMipmap(GL_TEXTURE_2D);
[/code]
1

Share this post


Link to post
Share on other sites
Confirmed and working! Thank you, that was much easier than all the hassle of generating my own and passing them to GLSL or something. Now I just need to brush up on some matrix maths and I'm good to go lol.
0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0

  • Similar Content

    • By fllwr0491
      I googled around but are unable to find source code or details of implementation.
      What keywords should I search for this topic?
      Things I would like to know:
      A. How to ensure that partially covered pixels are rasterized?
         Apparently by expanding each triangle by 1 pixel or so, rasterization problem is almost solved.
         But it will result in an unindexable triangle list without tons of overlaps. Will it incur a large performance penalty?
      B. A-buffer like bitmask needs a read-modiry-write operation.
         How to ensure proper synchronizations in GLSL?
         GLSL seems to only allow int32 atomics on image.
      C. Is there some simple ways to estimate coverage on-the-fly?
         In case I am to draw 2D shapes onto an exisitng target:
         1. A multi-pass whatever-buffer seems overkill.
         2. Multisampling could cost a lot memory though all I need is better coverage.
            Besides, I have to blit twice, if draw target is not multisampled.
       
    • By mapra99
      Hello

      I am working on a recent project and I have been learning how to code in C# using OpenGL libraries for some graphics. I have achieved some quite interesting things using TAO Framework writing in Console Applications, creating a GLUT Window. But my problem now is that I need to incorporate the Graphics in a Windows Form so I can relate the objects that I render with some .NET Controls.

      To deal with this problem, I have seen in some forums that it's better to use OpenTK instead of TAO Framework, so I can use the glControl that OpenTK libraries offer. However, I haven't found complete articles, tutorials or source codes that help using the glControl or that may insert me into de OpenTK functions. Would somebody please share in this forum some links or files where I can find good documentation about this topic? Or may I use another library different of OpenTK?

      Thanks!
    • By Solid_Spy
      Hello, I have been working on SH Irradiance map rendering, and I have been using a GLSL pixel shader to render SH irradiance to 2D irradiance maps for my static objects. I already have it working with 9 3D textures so far for the first 9 SH functions.
      In my GLSL shader, I have to send in 9 SH Coefficient 3D Texures that use RGBA8 as a pixel format. RGB being used for the coefficients for red, green, and blue, and the A for checking if the voxel is in use (for the 3D texture solidification shader to prevent bleeding).
      My problem is, I want to knock this number of textures down to something like 4 or 5. Getting even lower would be a godsend. This is because I eventually plan on adding more SH Coefficient 3D Textures for other parts of the game map (such as inside rooms, as opposed to the outside), to circumvent irradiance probe bleeding between rooms separated by walls. I don't want to reach the 32 texture limit too soon. Also, I figure that it would be a LOT faster.
      Is there a way I could, say, store 2 sets of SH Coefficients for 2 SH functions inside a texture with RGBA16 pixels? If so, how would I extract them from inside GLSL? Let me know if you have any suggestions ^^.
    • By KarimIO
      EDIT: I thought this was restricted to Attribute-Created GL contexts, but it isn't, so I rewrote the post.
      Hey guys, whenever I call SwapBuffers(hDC), I get a crash, and I get a "Too many posts were made to a semaphore." from Windows as I call SwapBuffers. What could be the cause of this?
      Update: No crash occurs if I don't draw, just clear and swap.
      static PIXELFORMATDESCRIPTOR pfd = // pfd Tells Windows How We Want Things To Be { sizeof(PIXELFORMATDESCRIPTOR), // Size Of This Pixel Format Descriptor 1, // Version Number PFD_DRAW_TO_WINDOW | // Format Must Support Window PFD_SUPPORT_OPENGL | // Format Must Support OpenGL PFD_DOUBLEBUFFER, // Must Support Double Buffering PFD_TYPE_RGBA, // Request An RGBA Format 32, // Select Our Color Depth 0, 0, 0, 0, 0, 0, // Color Bits Ignored 0, // No Alpha Buffer 0, // Shift Bit Ignored 0, // No Accumulation Buffer 0, 0, 0, 0, // Accumulation Bits Ignored 24, // 24Bit Z-Buffer (Depth Buffer) 0, // No Stencil Buffer 0, // No Auxiliary Buffer PFD_MAIN_PLANE, // Main Drawing Layer 0, // Reserved 0, 0, 0 // Layer Masks Ignored }; if (!(hDC = GetDC(windowHandle))) return false; unsigned int PixelFormat; if (!(PixelFormat = ChoosePixelFormat(hDC, &pfd))) return false; if (!SetPixelFormat(hDC, PixelFormat, &pfd)) return false; hRC = wglCreateContext(hDC); if (!hRC) { std::cout << "wglCreateContext Failed!\n"; return false; } if (wglMakeCurrent(hDC, hRC) == NULL) { std::cout << "Make Context Current Second Failed!\n"; return false; } ... // OGL Buffer Initialization glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT); glBindVertexArray(vao); glUseProgram(myprogram); glDrawElements(GL_TRIANGLES, indexCount, GL_UNSIGNED_SHORT, (void *)indexStart); SwapBuffers(GetDC(window_handle));  
    • By Tchom
      Hey devs!
       
      I've been working on a OpenGL ES 2.0 android engine and I have begun implementing some simple (point) lighting. I had something fairly simple working, so I tried to get fancy and added color-tinting light. And it works great... with only one or two lights. Any more than that, the application drops about 15 frames per light added (my ideal is at least 4 or 5). I know implementing lighting is expensive, I just didn't think it was that expensive. I'm fairly new to the world of OpenGL and GLSL, so there is a good chance I've written some crappy shader code. If anyone had any feedback or tips on how I can optimize this code, please let me know.
       
      Vertex Shader
      uniform mat4 u_MVPMatrix; uniform mat4 u_MVMatrix; attribute vec4 a_Position; attribute vec3 a_Normal; attribute vec2 a_TexCoordinate; varying vec3 v_Position; varying vec3 v_Normal; varying vec2 v_TexCoordinate; void main() { v_Position = vec3(u_MVMatrix * a_Position); v_TexCoordinate = a_TexCoordinate; v_Normal = vec3(u_MVMatrix * vec4(a_Normal, 0.0)); gl_Position = u_MVPMatrix * a_Position; } Fragment Shader
      precision mediump float; uniform vec4 u_LightPos["+numLights+"]; uniform vec4 u_LightColours["+numLights+"]; uniform float u_LightPower["+numLights+"]; uniform sampler2D u_Texture; varying vec3 v_Position; varying vec3 v_Normal; varying vec2 v_TexCoordinate; void main() { gl_FragColor = (texture2D(u_Texture, v_TexCoordinate)); float diffuse = 0.0; vec4 colourSum = vec4(1.0); for (int i = 0; i < "+numLights+"; i++) { vec3 toPointLight = vec3(u_LightPos[i]); float distance = length(toPointLight - v_Position); vec3 lightVector = normalize(toPointLight - v_Position); float diffuseDiff = 0.0; // The diffuse difference contributed from current light diffuseDiff = max(dot(v_Normal, lightVector), 0.0); diffuseDiff = diffuseDiff * (1.0 / (1.0 + ((1.0-u_LightPower[i])* distance * distance))); //Determine attenuatio diffuse += diffuseDiff; gl_FragColor.rgb *= vec3(1.0) / ((vec3(1.0) + ((vec3(1.0) - vec3(u_LightColours[i]))*diffuseDiff))); //The expensive part } diffuse += 0.1; //Add ambient light gl_FragColor.rgb *= diffuse; } Am I making any rookie mistakes? Or am I just being unrealistic about what I can do? Thanks in advance
  • Popular Now