CODEWITHSUNDEEP
c++texturesshaderopengl-3
ram
ram

Reputation: 124

Display two objects using OpenGL. Textures not behaving as expected

Hi, I am trying to display two objects using OpenGL viz., 1) a rotating cube with a mix of two textures (a wooden crate pattern and a smiley) in the foreground and 2) rectangular plate with just one texture (dark grey wood) as a background. When I comment out the part of the code governing the display of rectangular plate, the rotating cube displays both the textures (wooden crate and smiley). Otherwise, the cube displays only the wooden crate texture and the dark grey wood texture is also displayed on the rectangular plate, i.e. the smiley texture disappears from the rotating cube. Please find the images 1) http://oi68.tinypic.com/2la4r3c.jpg (with the rectangular plate portion of code commented) and 2) http://i67.tinypic.com/9u9rpf.jpg (without the rectangular plate portion of code commented). The relavant portion of the code is pasted below 

// Rotating Cube ===================================================
// Texture of wooden crate
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture1);
glUniform1i(glGetUniformLocation(ourShader_box.Program, "ourTexture1"), 0);

// Texture of a smiley
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, texture2);
glUniform1i(glGetUniformLocation(ourShader_box.Program, "ourTexture2"), 1);

// lets use the box shader for the cube
ourShader_box.Use();

// transformations for the rotating cube ---------------------------------
glm::mat4 model_box, model1, model2;
glm::mat4 view_box;
glm::mat4 perspective;

perspective = glm::perspective(45.0f, (GLfloat)width_screen/(GLfloat)height_screen, 0.1f, 200.0f);

model1 = glm::rotate(model_box, (GLfloat)glfwGetTime()*1.0f, glm::vec3(0.5f, 1.0f, 0.0f));
model2 = glm::rotate(model_box, (GLfloat)glfwGetTime()*1.0f, glm::vec3(0.0f, 1.0f, 0.5f));
model_box = model1 * model2;

view_box= glm::translate(view_box, glm::vec3(1.0f, 0.0f, -3.0f));

GLint modelLoc_box = glGetUniformLocation(ourShader_box.Program, "model");
GLint viewLoc_box = glGetUniformLocation(ourShader_box.Program, "view");
GLint projLoc_box = glGetUniformLocation(ourShader_box.Program, "perspective");

glUniformMatrix4fv(modelLoc_box, 1, GL_FALSE, glm::value_ptr(model_box));
glUniformMatrix4fv(viewLoc_box, 1, GL_FALSE, glm::value_ptr(view_box));
glUniformMatrix4fv(projLoc_box, 1, GL_FALSE, glm::value_ptr(perspective));  
// --------------------------------------------------------------------

// Draw calls
glBindVertexArray(VAO_box);
glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(0);

// Rectangular Plate =====================================================
// Background Shader
ourShader_bg.Use();

// Texture of dark grey wood
glActiveTexture(GL_TEXTURE2);
glBindTexture(GL_TEXTURE_2D, texture_wood);
glUniform1i(glGetUniformLocation(ourShader_bg.Program, "ourTexture3"), 2);

// Transformations -------------------------------------------
glm::mat4 model_bg;
glm::mat4 view_bg;

GLint modelLoc_bg = glGetUniformLocation(ourShader_bg.Program, "model");
GLint viewLoc_bg= glGetUniformLocation(ourShader_bg.Program, "view");
GLint projLoc_bg = glGetUniformLocation(ourShader_bg.Program, "perspective");

glUniformMatrix4fv(modelLoc_bg, 1, GL_FALSE, glm::value_ptr(model_bg));
glUniformMatrix4fv(viewLoc_bg, 1, GL_FALSE, glm::value_ptr(view_bg));
glUniformMatrix4fv(projLoc_bg, 1, GL_FALSE, glm::value_ptr(perspective));   
// -----------------------------------------------------------

// Draw calls
glBindVertexArray(VAO_bg);
glDrawArrays(GL_TRIANGLES, 0, 6);
glBindVertexArray(0);
// =================================================================

I have a two questions regarding this code.

Upvotes: 0

Views: 135

Answers (1)

synapse
synapse

Reputation: 128

You are using the same shader, same matrices and you have the same geometry type for the two objects (triangles), so why set the shader twice ? Did you try to;

  • Set shader
  • Bind buffer #1
  • Bind texture #1
  • Draw object #1
  • Bind buffer #2
  • Bind texture #2
  • Draw object #2

Upvotes: 1

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