这是我的顶点着色器：
attribute vec4 a_position;
uniform mat4 u_projection;
uniform vec4 u_origin_translation;
uniform vec4 u_translation;
attribute vec2 a_texCoord;
varying vec2 v_texCoord;
uniform vec4 u_color;
varying vec4 v_color;
attribute vec4 a_color;
void main()
{
vec4 pos = a_position + u_origin_translation + u_translation;
gl_Position = u_projection * pos;
v_texCoord = a_texCoord;
v_color = a_color * u_color;
}
和像素着色器：
precision mediump float;
varying vec2 v_texCoord;
uniform sampler2D s_texture;
varying vec4 v_color;
void main()
{
vec4 texColor = texture2D(s_texture, v_texCoord);
gl_FragColor = texColor * v_color;
}
我试图在Marmalade 7.1平台上在OpenGL ES 2.0上下文中渲染纹理四边形；
将矩阵数据(投影均匀">u_projection")发送到着色器的源代码：
GLint projectionUniformLocation = glGetUniformLocation(m_ShaderProgram->GetHandle(), m_ShaderProgram->GetProjectionUniformName().c_str());
glUniformMatrix4fv(projectionUniformLocation, 1, 0, &m_Ortho[0]);
我的跟踪代码：
glGetActiveUniform(m_ShaderProgram->GetHandle(), projectionUniformLocation, maxUniformLength, 0, &size, &type, &buffer[0]);
TRACE_OUT("Context::ApplyOrtho: type is matrix " << (type == GL_FLOAT_MAT4));
TRACE_OUT("Context::ApplyOrtho: type is " << type);
TRACE_OUT("Context::ApplyOrtho: buffer is " << &buffer[0]);
TRACE_OUT("Context::ApplyOrtho: projectionUniformLocation is " << projectionUniformLocation);
整个程序在Windows模拟器中运行良好。它显示了有纹理的四边形，从跟踪我的项目来看，UniformLocation是GL_FLOAT_MAT4的类型，所以它是正确的。
但是！！！当我在iPad3上运行它时，相同的代码以另一种方式工作。跟踪表明我的项目UniformLocation不是GL_FLOAT_MAT4，但它是GL_SAMPLER_2D并且输出缓冲区消息包含">s_texture">可见的结果是没有纹理的黑色四边形。
更新：在模拟器projectionUniformLocation中的Windows上，索引为3，但在ipad上，它的索引为2；
更新2:模拟器的活动制服列表：
Context::PrintActiveUniforms: active is s_texture and it's location is 0
Context::PrintActiveUniforms: active is u_color and it's location is 1
Context::PrintActiveUniforms: active is u_origin_translation and it's location is 2
Context::PrintActiveUniforms: active is u_projection and it's location is 3
Context::PrintActiveUniforms: active is u_translation and it's location is 4
和从ipad上市：
Context::PrintActiveUniforms: active is u_origin_translation and it's location is 0
Context::PrintActiveUniforms: active is u_color and it's location is 1
Context::PrintActiveUniforms: active is s_texture and it's location is 7
Context::PrintActiveUniforms: active is u_projection and it's location is 2
Context::PrintActiveUniforms: active is u_translation and it's location is 6
更新3:关于iPad3制服的更多信息(Andon M.Coleman感谢您提供源代码)：
eTB_GLSL__print_uniforms: (loc=0) type=vec4 name=u_origin_translation size=1
eTB_GLSL__print_uniforms: (loc=1) type=vec4 name=u_color size=1
eTB_GLSL__print_uniforms: (loc=7) type=sampler2D name=s_texture size=1
eTB_GLSL__print_uniforms: (loc=2) type=mat4 name=u_projection size=1
eTB_GLSL__print_uniforms: (loc=6) type=vec4 name=u_translation size=1
为什么glGetActiveUniform说我的u_projection不是mat4，为什么我看不到我的纹理
有什么想法吗？
幸运的是，这个问题对我有帮助。两行代码解决了我的问题，纹理出现了：
glTexParameteri ( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
glTexParameteri ( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );