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OpenGL Fixing shaders for lighting terrain.

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I've been making a new opengl program which uses shaders and the shaders support up to 8 dynamic lights.
This worked fine when I was just loading models and testing them.
But now that I've added some terrain the light acts very odd with it.

farAwayHillside.png
The further away from the light I go, the more you can actually see it.

closeUpHillside.png
If you get within a reasonable distance, however, the lights vanish.

litPlants.png
This bug does not seem to effect the models very much.

Here is my fragment shader:

#version 330 core

// Interpolated values from the vertex shaders
in vec2 UV;
in vec3 Position_worldspace;
in vec3 Normal_cameraspace;
in vec3 EyeDirection_cameraspace;
in vec3 ambientColor;
in vec3 diffuseColor;
in vec3 specularColor;

in vec3 Light0Direction_cameraspace;
in vec3 Light1Direction_cameraspace;
in vec3 Light2Direction_cameraspace;
in vec3 Light3Direction_cameraspace;
in vec3 Light4Direction_cameraspace;
in vec3 Light5Direction_cameraspace;
in vec3 Light6Direction_cameraspace;
in vec3 Light7Direction_cameraspace;

// Ouput data
out vec3 color;

// Values that stay constant for the whole mesh.
uniform sampler2D myTextureSampler;
uniform mat4 MV;
uniform int textured;
uniform int terrain;
uniform vec3 worldAmbient;

uniform vec3 Light0_Position;
uniform vec3 Light1_Position;
uniform vec3 Light2_Position;
uniform vec3 Light3_Position;
uniform vec3 Light4_Position;
uniform vec3 Light5_Position;
uniform vec3 Light6_Position;
uniform vec3 Light7_Position;

uniform vec3 Light0_Color;
uniform vec3 Light1_Color;
uniform vec3 Light2_Color;
uniform vec3 Light3_Color;
uniform vec3 Light4_Color;
uniform vec3 Light5_Color;
uniform vec3 Light6_Color;
uniform vec3 Light7_Color;

uniform float Light0_Power;
uniform float Light1_Power;
uniform float Light2_Power;
uniform float Light3_Power;
uniform float Light4_Power;
uniform float Light5_Power;
uniform float Light6_Power;
uniform float Light7_Power;

void main()
{
	// Material properties
	vec3 MaterialDiffuseColor = diffuseColor;
	vec3 MaterialAmbientColor = ambientColor;
	vec3 MaterialSpecularColor = specularColor;

	if(terrain == 1)
	{
		MaterialAmbientColor = texture2D( myTextureSampler, UV ).rgb * worldAmbient;
		MaterialDiffuseColor = MaterialAmbientColor;
		MaterialSpecularColor = vec3(0,0,0);
	}
	else
	{

	if(textured == 1)
	{
		MaterialAmbientColor = texture2D( myTextureSampler, UV ).rgb * worldAmbient;
		MaterialDiffuseColor = diffuseColor * texture2D( myTextureSampler, UV ).rgb;
		MaterialSpecularColor = specularColor;
	}
	else
	{
		//blender wasn't exporting ambient colors, so we're using diffuse for now
		MaterialAmbientColor = MaterialDiffuseColor * worldAmbient;
	}

	}

	float distance0 = length( Light0_Position - Position_worldspace );
	float distance1 = length( Light1_Position - Position_worldspace );
	float distance2 = length( Light2_Position - Position_worldspace );
	float distance3 = length( Light3_Position - Position_worldspace );
	float distance4 = length( Light4_Position - Position_worldspace );
	float distance5 = length( Light5_Position - Position_worldspace );
	float distance6 = length( Light6_Position - Position_worldspace );
	float distance7 = length( Light7_Position - Position_worldspace );

	vec3 n = normalize( Normal_cameraspace );
	vec3 E = normalize(EyeDirection_cameraspace);

	vec3 l0 = normalize( Light0Direction_cameraspace );
	float cosTheta0 = clamp( dot( n,l0 ), 0,1 );

	vec3 l1 = normalize( Light1Direction_cameraspace );
	float cosTheta1 = clamp( dot( n,l1 ), 0,1 );

	vec3 l2 = normalize( Light2Direction_cameraspace );
	float cosTheta2 = clamp( dot( n,l2 ), 0,1 );

	vec3 l3 = normalize( Light3Direction_cameraspace );
	float cosTheta3 = clamp( dot( n,l3 ), 0,1 );

	vec3 l4 = normalize( Light4Direction_cameraspace );
	float cosTheta4 = clamp( dot( n,l4 ), 0,1 );

	vec3 l5 = normalize( Light5Direction_cameraspace );
	float cosTheta5 = clamp( dot( n,l5 ), 0,1 );

	vec3 l6 = normalize( Light6Direction_cameraspace );
	float cosTheta6 = clamp( dot( n,l6 ), 0,1 );

	vec3 l7 = normalize( Light7Direction_cameraspace );
	float cosTheta7 = clamp( dot( n,l7 ), 0,1 );

	vec3 R0 = reflect(-l0,n);
	float cosAlpha0 = clamp( dot( E,R0 ), 0,1 );

	vec3 R1 = reflect(-l1,n);
	float cosAlpha1 = clamp( dot( E,R1 ), 0,1 );

	vec3 R2 = reflect(-l2,n);
	float cosAlpha2 = clamp( dot( E,R2 ), 0,1 );

	vec3 R3 = reflect(-l3,n);
	float cosAlpha3 = clamp( dot( E,R3 ), 0,1 );

	vec3 R4 = reflect(-l4,n);
	float cosAlpha4 = clamp( dot( E,R4 ), 0,1 );

	vec3 R5 = reflect(-l5,n);
	float cosAlpha5 = clamp( dot( E,R5 ), 0,1 );

	vec3 R6 = reflect(-l6,n);
	float cosAlpha6 = clamp( dot( E,R6 ), 0,1 );

	vec3 R7 = reflect(-l7,n);
	float cosAlpha7 = clamp( dot( E,R7 ), 0,1 );

	vec3 colorPower0 = Light0_Color * Light0_Power;
	vec3 colorPower1 = Light1_Color * Light1_Power;
	vec3 colorPower2 = Light2_Color * Light2_Power;
	vec3 colorPower3 = Light3_Color * Light3_Power;
	vec3 colorPower4 = Light4_Color * Light4_Power;
	vec3 colorPower5 = Light5_Color * Light5_Power;
	vec3 colorPower6 = Light6_Color * Light6_Power;
	vec3 colorPower7 = Light7_Color * Light7_Power;

	vec3 MaterialDiffuseColor0 = colorPower0 * cosTheta0 / (distance0*distance0);
	vec3 MaterialSpecularColor0 = Light0_Color * Light0_Power * pow(cosAlpha0,5) / (distance0*distance0);

	vec3 MaterialDiffuseColor1 = colorPower1 * cosTheta1 / (distance1*distance1);
	vec3 MaterialSpecularColor1 = Light1_Color * Light1_Power * pow(cosAlpha1,5) / (distance1*distance1);

	vec3 MaterialDiffuseColor2 = colorPower2 * cosTheta2 / (distance2*distance2);
	vec3 MaterialSpecularColor2 = Light2_Color * Light2_Power * pow(cosAlpha2,5) / (distance2*distance2);

	vec3 MaterialDiffuseColor3 = colorPower3 * cosTheta3 / (distance3*distance3);
	vec3 MaterialSpecularColor3 = Light3_Color * Light3_Power * pow(cosAlpha3,5) / (distance3*distance3);

	vec3 MaterialDiffuseColor4 = colorPower4 * cosTheta4 / (distance4*distance4);
	vec3 MaterialSpecularColor4 = Light4_Color * Light4_Power * pow(cosAlpha4,5) / (distance4*distance4);

	vec3 MaterialDiffuseColor5 = colorPower5 * cosTheta5 / (distance5*distance5);
	vec3 MaterialSpecularColor5 = Light5_Color * Light5_Power * pow(cosAlpha5,5) / (distance5*distance5);

	vec3 MaterialDiffuseColor6 = colorPower6 * cosTheta6 / (distance6*distance6);
	vec3 MaterialSpecularColor6 = Light6_Color * Light6_Power * pow(cosAlpha6,5) / (distance6*distance6);

	vec3 MaterialDiffuseColor7 = colorPower7 * cosTheta7 / (distance7*distance7);
	vec3 MaterialSpecularColor7 = Light7_Color * Light7_Power * pow(cosAlpha7,5) / (distance7*distance7);
	
	color = MaterialAmbientColor;

	color += (MaterialDiffuseColor * MaterialDiffuseColor0) + (MaterialSpecularColor * MaterialSpecularColor0);
	color += (MaterialDiffuseColor * MaterialDiffuseColor1) + (MaterialSpecularColor * MaterialSpecularColor1);
	color += (MaterialDiffuseColor * MaterialDiffuseColor2) + (MaterialSpecularColor * MaterialSpecularColor2);
	color += (MaterialDiffuseColor * MaterialDiffuseColor3) + (MaterialSpecularColor * MaterialSpecularColor3);
	color += (MaterialDiffuseColor * MaterialDiffuseColor4) + (MaterialSpecularColor * MaterialSpecularColor4);
	color += (MaterialDiffuseColor * MaterialDiffuseColor5) + (MaterialSpecularColor * MaterialSpecularColor5);
	color += (MaterialDiffuseColor * MaterialDiffuseColor6) + (MaterialSpecularColor * MaterialSpecularColor6);
	color += (MaterialDiffuseColor * MaterialDiffuseColor7) + (MaterialSpecularColor * MaterialSpecularColor7);
}

My vertex shader:

#version 330 core

// Input vertex data, different for all executions of this shader.
layout(location = 0) in vec3 vertexPosition_modelspace;
layout(location = 1) in vec2 vertexUV;
layout(location = 2) in vec3 vertexNormal_modelspace;
layout(location = 3) in vec3 vertexAmbientColor;
layout(location = 4) in vec3 vertexDiffuseColor;
layout(location = 5) in vec3 vertexSpecularColor;

// Output data ; will be interpolated for each fragment.
out vec2 UV;
out vec3 Position_worldspace;
out vec3 Normal_cameraspace;
out vec3 EyeDirection_cameraspace;
out vec3 ambientColor;
out vec3 diffuseColor;
out vec3 specularColor;

out vec3 Light0Direction_cameraspace;
out vec3 Light1Direction_cameraspace;
out vec3 Light2Direction_cameraspace;
out vec3 Light3Direction_cameraspace;
out vec3 Light4Direction_cameraspace;
out vec3 Light5Direction_cameraspace;
out vec3 Light6Direction_cameraspace;
out vec3 Light7Direction_cameraspace;

// Values that stay constant for the whole mesh.
uniform mat4 MVP;
uniform mat4 V;
uniform mat4 M;

uniform vec3 Light0_Position;
uniform vec3 Light1_Position;
uniform vec3 Light2_Position;
uniform vec3 Light3_Position;
uniform vec3 Light4_Position;
uniform vec3 Light5_Position;
uniform vec3 Light6_Position;
uniform vec3 Light7_Position;

void main()
{
	// Output position of the vertex, in clip space : MVP * position
	gl_Position =  MVP * vec4(vertexPosition_modelspace,1);
	
	// Position of the vertex, in worldspace : M * position
	Position_worldspace = (M * vec4(vertexPosition_modelspace,1)).xyz;
	
	// Vector that goes from the vertex to the camera, in camera space.
	// In camera space, the camera is at the origin (0,0,0).
	vec3 vertexPosition_cameraspace = ( V * M * vec4(vertexPosition_modelspace,1)).xyz;
	EyeDirection_cameraspace = vec3(0,0,0) - vertexPosition_cameraspace;

	// Vector that goes from the vertex to the light, in camera space. M is ommited because it's identity.
	
	vec3 Light0Position_cameraspace = ( V * vec4(Light0_Position,0)).xyz;
	Light0Direction_cameraspace = Light0Position_cameraspace + EyeDirection_cameraspace;
	vec3 Light1Position_cameraspace = ( V * vec4(Light1_Position,0)).xyz;
	Light1Direction_cameraspace = Light1Position_cameraspace + EyeDirection_cameraspace;
	vec3 Light2Position_cameraspace = ( V * vec4(Light2_Position,0)).xyz;
	Light2Direction_cameraspace = Light2Position_cameraspace + EyeDirection_cameraspace;
	vec3 Light3Position_cameraspace = ( V * vec4(Light3_Position,0)).xyz;
	Light3Direction_cameraspace = Light3Position_cameraspace + EyeDirection_cameraspace;
	vec3 Light4Position_cameraspace = ( V * vec4(Light4_Position,0)).xyz;
	Light4Direction_cameraspace = Light4Position_cameraspace + EyeDirection_cameraspace;
	vec3 Light5Position_cameraspace = ( V * vec4(Light5_Position,0)).xyz;
	Light5Direction_cameraspace = Light5Position_cameraspace + EyeDirection_cameraspace;
	vec3 Light6Position_cameraspace = ( V * vec4(Light6_Position,0)).xyz;
	Light6Direction_cameraspace = Light6Position_cameraspace + EyeDirection_cameraspace;
	vec3 Light7Position_cameraspace = ( V * vec4(Light7_Position,0)).xyz;
	Light7Direction_cameraspace = Light7Position_cameraspace + EyeDirection_cameraspace;
	
	// Normal of the the vertex, in camera space
	Normal_cameraspace = ( V * M * vec4(vertexNormal_modelspace,0)).xyz; // Only correct if ModelMatrix does not scale the model ! Use its inverse transpose if not.
	
	// UV of the vertex. No special space for this one.
	UV = vertexUV;
	diffuseColor = vertexDiffuseColor;
	ambientColor = vertexAmbientColor;
	specularColor = vertexSpecularColor;
}

And some code from the program itself:

int heightMap[200][200];
GLuint terrainVAO;
GLuint terrainTexture;
GLuint terrainVertBuffer;
GLuint terrainNormalBuffer;
GLuint terrainUVBuffer;
GLuint terrainDiffBuffer;
GLuint terrainSpecBuffer;
vector<glm::vec3> terrainVerts;
vector<glm::vec2> terrainUVs;
vector<glm::vec3> terrainNormals;
vector<glm::vec3> terrainSpecs;
vector<glm::vec3> terrainDiffs;

struct tmpVec3
{
    float x,y,z;
};

tmpVec3 cross(float x1,float y1,float z1,float x2,float y2,float z2)
{
    tmpVec3 ret;
    ret.x = (y1*z2) - (z1*y2);
    ret.y = (z1*x2) - (x1*z2);
    ret.z = (x1*y2) - (y1*x2);
    return ret;
}

tmpVec3 normalize(tmpVec3 in)
{
    float length;
    length = sqrt(pow(in.x,2)+pow(in.y,2)+pow(in.z,2));
    in.x /= length;
    in.y /= length;
    in.z /= length;
    return in;
}

void recompileHeightmap()
{
    terrainVerts.empty();
    terrainUVs.empty();
    terrainNormals.empty();

    for(int x = 0; x<199; x++)
    {
        for(int z = 0; z<199; z++)
        {

            glm::vec3 temp1(-(x),heightMap[x][z],-(z));
            glm::vec3 temp2(-(x),heightMap[x][z+1],-(z+1));
            glm::vec3 temp3(-(x+1),heightMap[x+1][z],-(z));

            glm::vec3 temp4(-(x+1),heightMap[x+1][z+1],-(z+1));
            glm::vec3 temp5(-(x+1),heightMap[x+1][z],-(z));
            glm::vec3 temp6(-(x),heightMap[x][z+1],-(z+1));

            terrainVerts.push_back(temp1);
            terrainVerts.push_back(temp2);
            terrainVerts.push_back(temp3);
            terrainVerts.push_back(temp4);
            terrainVerts.push_back(temp5);
            terrainVerts.push_back(temp6);

            glm::vec3 tempDiff(1,1,1);
            glm::vec3 tempSpec(0,0,0);

            terrainDiffs.push_back(tempDiff);
            terrainDiffs.push_back(tempDiff);
            terrainDiffs.push_back(tempDiff);
            terrainDiffs.push_back(tempDiff);
            terrainDiffs.push_back(tempDiff);
            terrainDiffs.push_back(tempDiff);

            terrainSpecs.push_back(tempSpec);
            terrainSpecs.push_back(tempSpec);
            terrainSpecs.push_back(tempSpec);
            terrainSpecs.push_back(tempSpec);
            terrainSpecs.push_back(tempSpec);
            terrainSpecs.push_back(tempSpec);

            int randNum = rand() % 4;

            if(randNum == 0)
            {
                glm::vec2 uv1(0,0);
                glm::vec2 uv2(0,1);
                glm::vec2 uv3(1,0);

                glm::vec2 uv4(1,1);
                glm::vec2 uv5(1,0);
                glm::vec2 uv6(0,1);

                terrainUVs.push_back(uv1);
                terrainUVs.push_back(uv2);
                terrainUVs.push_back(uv3);
                terrainUVs.push_back(uv4);
                terrainUVs.push_back(uv5);
                terrainUVs.push_back(uv6);
            }
            else if(randNum == 1)
            {
                glm::vec2 uv1(1,1);
                glm::vec2 uv2(1,0);
                glm::vec2 uv3(0,1);

                glm::vec2 uv4(1,1);
                glm::vec2 uv5(1,0);
                glm::vec2 uv6(0,1);

                terrainUVs.push_back(uv1);
                terrainUVs.push_back(uv2);
                terrainUVs.push_back(uv3);
                terrainUVs.push_back(uv4);
                terrainUVs.push_back(uv5);
                terrainUVs.push_back(uv6);
            }
            else if(randNum == 2)
            {
                glm::vec2 uv1(0,0);
                glm::vec2 uv2(0,1);
                glm::vec2 uv3(1,0);

                glm::vec2 uv4(1,0);
                glm::vec2 uv5(0,1);
                glm::vec2 uv6(1,1);

                terrainUVs.push_back(uv1);
                terrainUVs.push_back(uv2);
                terrainUVs.push_back(uv3);
                terrainUVs.push_back(uv4);
                terrainUVs.push_back(uv5);
                terrainUVs.push_back(uv6);
            }
            else
            {
                glm::vec2 uv1(1,1);
                glm::vec2 uv2(1,0);
                glm::vec2 uv3(0,1);

                glm::vec2 uv4(1,1);
                glm::vec2 uv5(1,0);
                glm::vec2 uv6(0,1);

                terrainUVs.push_back(uv1);
                terrainUVs.push_back(uv2);
                terrainUVs.push_back(uv3);
                terrainUVs.push_back(uv4);
                terrainUVs.push_back(uv5);
                terrainUVs.push_back(uv6);
            }
        }
    }

    for(int i = 0; i<terrainVerts.size(); i+=3)
    {
        glm::vec3 first = terrainVerts[i];
        glm::vec3 second = terrainVerts[i+1];
        glm::vec3 third = terrainVerts[i+2];

        float v1x = second.x - first.x;
        float v1y = second.y - first.y;
        float v1z = second.z - first.z;
        float v2x = third.x - first.x;
        float v2y = third.y - first.y;
        float v2z = third.z - first.z;

        tmpVec3 ret = normalize(cross(v1x,v1y,v1z,v2x,v2y,v2z));

        glm::vec3 normal(-ret.x,ret.y,-ret.z);

        terrainNormals.push_back(normal);
        terrainNormals.push_back(normal);
        terrainNormals.push_back(normal);
    }

    glGenVertexArrays(1,&terrainVAO);
    glBindVertexArray(terrainVAO);

    glBindTexture(GL_TEXTURE_2D, terrainTexture);

    glGenBuffers(1, &terrainVertBuffer);
    glEnableVertexAttribArray(0);
    glBindBuffer(GL_ARRAY_BUFFER, terrainVertBuffer);
    glBufferData(GL_ARRAY_BUFFER, terrainVerts.size() * sizeof(glm::vec3), &terrainVerts[0], GL_STATIC_DRAW);
    glVertexAttribPointer(
            0,                  // attribute
            3,                  // size
            GL_FLOAT,           // type
            GL_FALSE,           // normalized?
            0,                  // stride
            (void*)0            // array buffer offset
    );

    glGenBuffers(1, &terrainUVBuffer);
    glEnableVertexAttribArray(1);
    glBindBuffer(GL_ARRAY_BUFFER, terrainUVBuffer);
    glBufferData(GL_ARRAY_BUFFER, terrainUVs.size() * sizeof(glm::vec2), &terrainUVs[0], GL_STATIC_DRAW);
    glVertexAttribPointer(
            1,                  // attribute
            2,                  // size
            GL_FLOAT,           // type
            GL_FALSE,           // normalized?
            0,                  // stride
            (void*)0            // array buffer offset
    );

    glGenBuffers(1, &terrainNormalBuffer);
    glEnableVertexAttribArray(2);
    glBindBuffer(GL_ARRAY_BUFFER, terrainNormalBuffer);
    glBufferData(GL_ARRAY_BUFFER, terrainNormals.size() * sizeof(glm::vec3), &terrainNormals[0], GL_STATIC_DRAW);
    glVertexAttribPointer(
            2,                                // attribute
            3,                                // size
            GL_FLOAT,                         // type
            GL_FALSE,                         // normalized?
            0,                                // stride
            (void*)0                          // array buffer offset
    );

        glGenBuffers(1, &terrainDiffBuffer);
        glEnableVertexAttribArray(4);
        glBindBuffer(GL_ARRAY_BUFFER, terrainDiffBuffer);
        glBufferData(GL_ARRAY_BUFFER, terrainDiffs.size() * sizeof(glm::vec3), &terrainDiffs[0], GL_STATIC_DRAW);
        glVertexAttribPointer(
                4,                                // attribute
                3,                                // size
                GL_FLOAT,                         // type
                GL_FALSE,                         // normalized?
                0,                                // stride
                (void*)0                          // array buffer offset
        );

        glGenBuffers(1, &terrainSpecBuffer);
        glEnableVertexAttribArray(5);
        glBindBuffer(GL_ARRAY_BUFFER, terrainSpecBuffer);
        glBufferData(GL_ARRAY_BUFFER, terrainSpecs.size() * sizeof(glm::vec3), &terrainSpecs[0], GL_STATIC_DRAW);
        glVertexAttribPointer(
                5,                                // attribute
                3,                                // size
                GL_FLOAT,                         // type
                GL_FALSE,                         // normalized?
                0,                                // stride
                (void*)0                          // array buffer offset
        );
}

Called each frame:

        glBindTexture(GL_TEXTURE_2D, terrainTexture);
        glBindVertexArray(terrainVAO);
        glDrawArrays(GL_TRIANGLES, 0, terrainVerts.size() );

I may not have provided enough information, however if there are any improvements at all that anyone can suggest, I'd love to hear them before I start devloping anything more advanced.
 

 

[media]http://www.youtube.com/watch?v=osi8v5TP-bk&feature=youtu.be[/media]

Edited by Syerjchep

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It somehow looks like your point light on the corner where your terrain goes up, moves with the camera. But that might be just visual / misleading.

Another thing you could test is moving that specific light source to eather the steaper or the flat mesh, and see what the result is. If is is correct, then you have to look somewhere where the lighting affects more then one (big) mesh, in this case the terrain.

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    • By Balma Alparisi
      i got error 1282 in my code.
      sf::ContextSettings settings; settings.majorVersion = 4; settings.minorVersion = 5; settings.attributeFlags = settings.Core; sf::Window window; window.create(sf::VideoMode(1600, 900), "Texture Unit Rectangle", sf::Style::Close, settings); window.setActive(true); window.setVerticalSyncEnabled(true); glewInit(); GLuint shaderProgram = createShaderProgram("FX/Rectangle.vss", "FX/Rectangle.fss"); float vertex[] = { -0.5f,0.5f,0.0f, 0.0f,0.0f, -0.5f,-0.5f,0.0f, 0.0f,1.0f, 0.5f,0.5f,0.0f, 1.0f,0.0f, 0.5,-0.5f,0.0f, 1.0f,1.0f, }; GLuint indices[] = { 0,1,2, 1,2,3, }; GLuint vao; glGenVertexArrays(1, &vao); glBindVertexArray(vao); GLuint vbo; glGenBuffers(1, &vbo); glBindBuffer(GL_ARRAY_BUFFER, vbo); glBufferData(GL_ARRAY_BUFFER, sizeof(vertex), vertex, GL_STATIC_DRAW); GLuint ebo; glGenBuffers(1, &ebo); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo); glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices,GL_STATIC_DRAW); glVertexAttribPointer(0, 3, GL_FLOAT, false, sizeof(float) * 5, (void*)0); glEnableVertexAttribArray(0); glVertexAttribPointer(1, 2, GL_FLOAT, false, sizeof(float) * 5, (void*)(sizeof(float) * 3)); glEnableVertexAttribArray(1); GLuint texture[2]; glGenTextures(2, texture); glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, texture[0]); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); sf::Image* imageOne = new sf::Image; bool isImageOneLoaded = imageOne->loadFromFile("Texture/container.jpg"); if (isImageOneLoaded) { glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, imageOne->getSize().x, imageOne->getSize().y, 0, GL_RGBA, GL_UNSIGNED_BYTE, imageOne->getPixelsPtr()); glGenerateMipmap(GL_TEXTURE_2D); } delete imageOne; glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, texture[1]); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); sf::Image* imageTwo = new sf::Image; bool isImageTwoLoaded = imageTwo->loadFromFile("Texture/awesomeface.png"); if (isImageTwoLoaded) { glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, imageTwo->getSize().x, imageTwo->getSize().y, 0, GL_RGBA, GL_UNSIGNED_BYTE, imageTwo->getPixelsPtr()); glGenerateMipmap(GL_TEXTURE_2D); } delete imageTwo; glUniform1i(glGetUniformLocation(shaderProgram, "inTextureOne"), 0); glUniform1i(glGetUniformLocation(shaderProgram, "inTextureTwo"), 1); GLenum error = glGetError(); std::cout << error << std::endl; sf::Event event; bool isRunning = true; while (isRunning) { while (window.pollEvent(event)) { if (event.type == event.Closed) { isRunning = false; } } glClear(GL_COLOR_BUFFER_BIT); if (isImageOneLoaded && isImageTwoLoaded) { glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, texture[0]); glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, texture[1]); glUseProgram(shaderProgram); } glBindVertexArray(vao); glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, nullptr); glBindVertexArray(0); window.display(); } glDeleteVertexArrays(1, &vao); glDeleteBuffers(1, &vbo); glDeleteBuffers(1, &ebo); glDeleteProgram(shaderProgram); glDeleteTextures(2,texture); return 0; } and this is the vertex shader
      #version 450 core layout(location=0) in vec3 inPos; layout(location=1) in vec2 inTexCoord; out vec2 TexCoord; void main() { gl_Position=vec4(inPos,1.0); TexCoord=inTexCoord; } and the fragment shader
      #version 450 core in vec2 TexCoord; uniform sampler2D inTextureOne; uniform sampler2D inTextureTwo; out vec4 FragmentColor; void main() { FragmentColor=mix(texture(inTextureOne,TexCoord),texture(inTextureTwo,TexCoord),0.2); } I was expecting awesomeface.png on top of container.jpg

    • By khawk
      We've just released all of the source code for the NeHe OpenGL lessons on our Github page at https://github.com/gamedev-net/nehe-opengl. code - 43 total platforms, configurations, and languages are included.
      Now operated by GameDev.net, NeHe is located at http://nehe.gamedev.net where it has been a valuable resource for developers wanting to learn OpenGL and graphics programming.

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    • By TheChubu
      The Khronos™ Group, an open consortium of leading hardware and software companies, announces from the SIGGRAPH 2017 Conference the immediate public availability of the OpenGL® 4.6 specification. OpenGL 4.6 integrates the functionality of numerous ARB and EXT extensions created by Khronos members AMD, Intel, and NVIDIA into core, including the capability to ingest SPIR-V™ shaders.
      SPIR-V is a Khronos-defined standard intermediate language for parallel compute and graphics, which enables content creators to simplify their shader authoring and management pipelines while providing significant source shading language flexibility. OpenGL 4.6 adds support for ingesting SPIR-V shaders to the core specification, guaranteeing that SPIR-V shaders will be widely supported by OpenGL implementations.
      OpenGL 4.6 adds the functionality of these ARB extensions to OpenGL’s core specification:
      GL_ARB_gl_spirv and GL_ARB_spirv_extensions to standardize SPIR-V support for OpenGL GL_ARB_indirect_parameters and GL_ARB_shader_draw_parameters for reducing the CPU overhead associated with rendering batches of geometry GL_ARB_pipeline_statistics_query and GL_ARB_transform_feedback_overflow_querystandardize OpenGL support for features available in Direct3D GL_ARB_texture_filter_anisotropic (based on GL_EXT_texture_filter_anisotropic) brings previously IP encumbered functionality into OpenGL to improve the visual quality of textured scenes GL_ARB_polygon_offset_clamp (based on GL_EXT_polygon_offset_clamp) suppresses a common visual artifact known as a “light leak” associated with rendering shadows GL_ARB_shader_atomic_counter_ops and GL_ARB_shader_group_vote add shader intrinsics supported by all desktop vendors to improve functionality and performance GL_KHR_no_error reduces driver overhead by allowing the application to indicate that it expects error-free operation so errors need not be generated In addition to the above features being added to OpenGL 4.6, the following are being released as extensions:
      GL_KHR_parallel_shader_compile allows applications to launch multiple shader compile threads to improve shader compile throughput WGL_ARB_create_context_no_error and GXL_ARB_create_context_no_error allow no error contexts to be created with WGL or GLX that support the GL_KHR_no_error extension “I’m proud to announce OpenGL 4.6 as the most feature-rich version of OpenGL yet. We've brought together the most popular, widely-supported extensions into a new core specification to give OpenGL developers and end users an improved baseline feature set. This includes resolving previous intellectual property roadblocks to bringing anisotropic texture filtering and polygon offset clamping into the core specification to enable widespread implementation and usage,” said Piers Daniell, chair of the OpenGL Working Group at Khronos. “The OpenGL working group will continue to respond to market needs and work with GPU vendors to ensure OpenGL remains a viable and evolving graphics API for all its customers and users across many vital industries.“
      The OpenGL 4.6 specification can be found at https://khronos.org/registry/OpenGL/index_gl.php. The GLSL to SPIR-V compiler glslang has been updated with GLSL 4.60 support, and can be found at https://github.com/KhronosGroup/glslang.
      Sophisticated graphics applications will also benefit from a set of newly released extensions for both OpenGL and OpenGL ES to enable interoperability with Vulkan and Direct3D. These extensions are named:
      GL_EXT_memory_object GL_EXT_memory_object_fd GL_EXT_memory_object_win32 GL_EXT_semaphore GL_EXT_semaphore_fd GL_EXT_semaphore_win32 GL_EXT_win32_keyed_mutex They can be found at: https://khronos.org/registry/OpenGL/index_gl.php
      Industry Support for OpenGL 4.6
      “With OpenGL 4.6 our customers have an improved set of core features available on our full range of OpenGL 4.x capable GPUs. These features provide improved rendering quality, performance and functionality. As the graphics industry’s most popular API, we fully support OpenGL and will continue to work closely with the Khronos Group on the development of new OpenGL specifications and extensions for our customers. NVIDIA has released beta OpenGL 4.6 drivers today at https://developer.nvidia.com/opengl-driver so developers can use these new features right away,” said Bob Pette, vice president, Professional Graphics at NVIDIA.
      "OpenGL 4.6 will be the first OpenGL release where conformant open source implementations based on the Mesa project will be deliverable in a reasonable timeframe after release. The open sourcing of the OpenGL conformance test suite and ongoing work between Khronos and X.org will also allow for non-vendor led open source implementations to achieve conformance in the near future," said David Airlie, senior principal engineer at Red Hat, and developer on Mesa/X.org projects.

      View full story
    • By _OskaR
      Hi,
      I have an OpenGL application but without possibility to wite own shaders.
      I need to perform small VS modification - is possible to do it in an alternative way? Do we have apps or driver modifictions which will catch the shader sent to GPU and override it?
    • By xhcao
      Does sync be needed to read texture content after access texture image in compute shader?
      My simple code is as below,
      glUseProgram(program.get());
      glBindImageTexture(0, texture[0], 0, GL_FALSE, 3, GL_READ_ONLY, GL_R32UI);
      glBindImageTexture(1, texture[1], 0, GL_FALSE, 4, GL_WRITE_ONLY, GL_R32UI);
      glDispatchCompute(1, 1, 1);
      // Does sync be needed here?
      glUseProgram(0);
      glBindFramebuffer(GL_READ_FRAMEBUFFER, framebuffer);
      glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
                                     GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, texture[1], 0);
      glReadPixels(0, 0, kWidth, kHeight, GL_RED_INTEGER, GL_UNSIGNED_INT, outputValues);
       
      Compute shader is very simple, imageLoad content from texture[0], and imageStore content to texture[1]. Does need to sync after dispatchCompute?
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