I am working to implement textures in my program. I have trimmed it down to display a single quad on-screen, with space around it showing background color black. In my texture class, I have used glGetError to make sure there was no problem with generating the texture, and I use glGetProgramiv to test my shaders.
When using colors in my fragment shader, everything seems to look just fine. I also know the data is packed correctly, because each triangle shows up as expected. The problem occurs as soon as I switch from getting my fragment color from the incoming vertex data to using a texture lookup. As soon as this change takes place, the entire screen goes white. I am using GLFW to handle window and input, and I know the program does not freeze because I can still use my exit key to close the program.
Here is my vertex and fragment shaders:
shader.vert
#version 430 core
layout(location = 0) in vec3 vPosition;
layout(location = 1) in vec2 vUV;
layout(location = 2) in vec3 vColor;
uniform mat4 MVP;
out vec4 color;
out vec2 uv;
void main() {
gl_Position = MVP * vec4(vPosition, 1.0f);
color = vec4(vColor, 1.0f);
uv = vUV;
}
shader.frag
#version 430 core
in vec2 uv;
in vec4 color;
out vec4 fColor;
uniform sampler2D Sampler;
void main() {
//fColor = color;
fColor = texture(Sampler, UV);
}
zTexture.cpp
#include "zTexture.h"
zTexture::zTexture() {
}
bool zTexture::loadTexture(const char* fileName) {
gli::texture Texture = gli::load(fileName);
if (Texture.empty())
return false;
gli::gl GL(gli::gl::PROFILE_GL33);
gli::gl::format const Format = GL.translate(Texture.format(), Texture.swizzles());
GLenum Target = GL.translate(Texture.target());
GLuint TextureName = 0;
glGenTextures(1, &TextureName);
GLenum e = glGetError();
glBindTexture(Target, TextureName);
e = glGetError();
glTexParameteri(Target, GL_TEXTURE_BASE_LEVEL, 0);
e = glGetError();
glTexParameteri(Target, GL_TEXTURE_MAX_LEVEL, static_cast<GLint>(Texture.levels() - 1));
e = glGetError();
glTexParameteri(Target, GL_TEXTURE_SWIZZLE_R, Format.Swizzles[0]);
e = glGetError();
glTexParameteri(Target, GL_TEXTURE_SWIZZLE_G, Format.Swizzles[1]);
e = glGetError();
glTexParameteri(Target, GL_TEXTURE_SWIZZLE_B, Format.Swizzles[2]);
e = glGetError();
glTexParameteri(Target, GL_TEXTURE_SWIZZLE_A, Format.Swizzles[3]);
e = glGetError();
glTexParameterf(Target, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
e = glGetError();
glTexParameterf(Target, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
e = glGetError();
glm::tvec3<GLsizei> const Extent(Texture.extent());
GLsizei const FaceTotal = static_cast<GLsizei>(Texture.layers() * Texture.faces());
switch (Texture.target())
{
case gli::TARGET_1D:
glTexStorage1D(Target, static_cast<GLint>(Texture.levels()), Format.Internal, Extent.x);
e = glGetError();
break;
case gli::TARGET_1D_ARRAY:
case gli::TARGET_2D:
case gli::TARGET_CUBE:
glTexStorage2D(Target, static_cast<GLint>(Texture.levels()), Format.Internal, Extent.x, Texture.target() == gli::TARGET_2D ? Extent.y : FaceTotal);
e = glGetError();
break;
case gli::TARGET_2D_ARRAY:
case gli::TARGET_3D:
case gli::TARGET_CUBE_ARRAY:
glTexStorage3D(Target, static_cast<GLint>(Texture.levels()), Format.Internal, Extent.x, Extent.y, Texture.target() == gli::TARGET_3D ? Extent.z : FaceTotal);
e = glGetError();
break;
default:
assert(0);
break;
}
for (std::size_t Layer = 0; Layer < Texture.layers(); ++Layer){
for (std::size_t Face = 0; Face < Texture.faces(); ++Face) {
for (std::size_t Level = 0; Level < Texture.levels(); ++Level)
{
GLsizei const LayerGL = static_cast<GLsizei>(Layer);
glm::tvec3<GLsizei> Extent(Texture.extent(Level));
Target = gli::is_target_cube(Texture.target()) ? static_cast<GLenum>(GL_TEXTURE_CUBE_MAP_POSITIVE_X + Face) : Target;
switch (Texture.target())
{
case gli::TARGET_1D:
if (gli::is_compressed(Texture.format())) {
glCompressedTexSubImage1D(Target, static_cast<GLint>(Level), 0, Extent.x, Format.Internal, static_cast<GLsizei>(Texture.size(Level)), Texture.data(Layer, Face, Level));
e = glGetError();
}
else {
glTexSubImage1D(Target, static_cast<GLint>(Level), 0, Extent.x, Format.External, Format.Type, Texture.data(Layer, Face, Level));
e = glGetError();
}
break;
case gli::TARGET_1D_ARRAY:
case gli::TARGET_2D:
case gli::TARGET_CUBE:
if (gli::is_compressed(Texture.format())) {
glCompressedTexSubImage2D(Target, static_cast<GLint>(Level), 0, 0, Extent.x, Texture.target() == gli::TARGET_1D_ARRAY ? LayerGL : Extent.y, Format.Internal, static_cast<GLsizei>(Texture.size(Level)), Texture.data(Layer, Face, Level));
e = glGetError();
}
else {
glTexSubImage2D(Target, static_cast<GLint>(Level), 0, 0, Extent.x, Texture.target() == gli::TARGET_1D_ARRAY ? LayerGL : Extent.y, Format.External, Format.Type, Texture.data(Layer, Face, Level));
e = glGetError();
}
break;
case gli::TARGET_2D_ARRAY:
case gli::TARGET_3D:
case gli::TARGET_CUBE_ARRAY:
if (gli::is_compressed(Texture.format())) {
glCompressedTexSubImage3D(Target, static_cast<GLint>(Level), 0, 0, 0, Extent.x, Extent.y, Texture.target() == gli::TARGET_3D ? Extent.z : LayerGL, Format.Internal, static_cast<GLsizei>(Texture.size(Level)), Texture.data(Layer, Face, Level));
e = glGetError();
}
else {
glTexSubImage3D(Target, static_cast<GLint>(Level), 0, 0, 0, Extent.x, Extent.y, Texture.target() == gli::TARGET_3D ? Extent.z : LayerGL, Format.External, Format.Type, Texture.data(Layer, Face, Level));
e = glGetError();
}
break;
default:
assert(0);
break;
}
}
}
}
e = glGetError();
glBindTexture(Target, 0);
e = glGetError();
texture = TextureName;
return true;
}
void zTexture::render(GLenum target){//, GLuint ID) {
glActiveTexture(target);
glBindTexture(GL_TEXTURE_2D, texture);
}
GLuint zTexture::getID() {
return texture;
}
and lastly, my vertex data
VertexData vertices[NumVertices] = {
{{-1.0f, -1.0f, 0.0f}, {0.0f, 0.0f}, {1.0f, 0.0f, 0.0f}},
{{1.0f, -1.0f, 0.0f}, {1.0f, 0.0f}, {0.0f, 0.0f, 1.0f}},
{{-1.0f, 1.0f, 0.0f}, {0.0f, 1.0f}, {0.0f, 1.0f, 0.0f}},
{{1.0f, 1.0f, 0.0f}, {1.0f, 1.0f}, {1.0f, 1.0f, 1.0f}}
};
GLuint indices[NumIndices] = { 0, 1, 2, 2, 1, 3 };
glEnableVertexAttribArray(vPosition);
glEnableVertexAttribArray(vUV);
glEnableVertexAttribArray(vColor);
glBindBuffer(GL_ARRAY_BUFFER, Buffers[ArrayBuffer]);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, Buffers[IndexBuffer]);
glVertexAttribPointer(vPosition, 3, GL_FLOAT, GL_FALSE, sizeof(VertexData), (void*)0);
glVertexAttribPointer(vUV, 2, GL_FLOAT, GL_FALSE, sizeof(VertexData), (void*)12);
glVertexAttribPointer(vColor, 3, GL_FLOAT, GL_FALSE, sizeof(VertexData), (void*)20);
myTex.render(GL_TEXTURE0);
glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
glDisableVertexAttribArray(vPosition);
glDisableVertexAttribArray(vUV);
glDisableVertexAttribArray(vColor);
Honestly I don’t know what other code is pertinent, as everything works fine until I switch my fragment shader from using the incoming color to using texture sampling. I appreciate any help!!