Hello,
I am doing a cross-platform project that uses C++ and OpenGL ( I know I should be using MoltenVK or Metal, but OpenGL is nice and simple for starting out and is cross platform). I am also doing most of my development on a M1 Macbook Pro, which supports up to OpenGL 4.1.
The M1 also only supports up to 16 active fragment shader samplers ( maximum number of supported image units)
I am currently working on a batch rendering system that uses an array of textures thats uploaded to the GPU and the shader can switch based off of the index into a sampler array. Heres the shader that I am using ( the vertex and fragment shaders are combined, but the program parses them separately) :
#type vertex
#version 410 core
layout(location = 0) in vec3 a_Position;
layout(location = 1) in vec4 a_Color;
layout(location = 2) in vec2 a_TexCoord;
layout(location = 3) in float a_TexIndex;
layout(location = 4) in float a_TilingFactor;
uniform mat4 u_ViewProjection;
out vec4 v_Color;
out vec2 v_TexCoord;
out float v_TexIndex;
out float v_TilingFactor;
void main()
{
v_Color = a_Color;
v_TexCoord = a_TexCoord;
v_TexIndex = a_TexIndex;
v_TilingFactor = a_TilingFactor;
gl_Position = u_ViewProjection * vec4(a_Position, 1.0);
}
#type fragment
#version 410 core
layout(location = 0) out vec4 color;
in vec4 v_Color;
in vec2 v_TexCoord;
in float v_TexIndex;
in float v_TilingFactor;
uniform sampler2D u_Textures[16];
void main()
{
color = texture(u_Textures[int(v_TexIndex)], v_TexCoord * v_TilingFactor) * v_Color;
}
However, when the program runs I get this message: UNSUPPORTED (log once): POSSIBLE ISSUE: unit 2 GLD_TEXTURE_INDEX_2D is unloadable and bound to sampler type (Float) - using zero texture because texture unloadable
I double and triple checked my code and im binding everything correctly to the shader (if im not feel free to point it out :), and the only thing I found on the web relating to this error was saying that it was an error within the GLSL compiler on the new M1s. Is this true? Or is it a code issue?
Thanks
side note: I am using EMACS to run Cmake and do C++ development, so if you try and test my project on Xcode and it doesnt include the shaders its most likely a Cmake/Xcode copy issue.
