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Text rendering working ok.

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This commit is contained in:
James Grogan 2022-11-15 17:16:38 +00:00
parent eef93efc29
commit 4849d83fcf
10 changed files with 127 additions and 42 deletions
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83
src/graphics/opengl/OpenGlPainter.cpp
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@ -72,23 +72,80 @@ void OpenGlPainter::renderTextLayer(const TextData& textData, DrawingContext* co
initializeTextShader();
}
auto first_char = textData.mContent[0];
auto iter = mFontTextures.find(first_char);
OpenGlFontTexture* working_texture{nullptr};
if (iter == mFontTextures.end())
for (auto c : textData.mContent)
{
auto glyph = context->getFontsManager()->getGlyph(first_char);
auto new_texture = std::make_unique<OpenGlFontTexture>(nullptr);
working_texture = new_texture.get();
mFontTextures[first_char] = std::move(new_texture);
}
else
{
working_texture = iter->second.get();
if (auto iter = mFontTextures.find(c); iter == mFontTextures.end())
{
auto glyph = context->getFontsManager()->getGlyph(textData.mFont.getFaceName(), textData.mFont.getSize(), c);
auto new_texture = std::make_unique<OpenGlFontTexture>(glyph);
mFontTextures[c] = std::move(new_texture);
}
}
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
const auto width = float(context->getSurface()->getWidth());
const auto height = float(context->getSurface()->getHeight());
glm::mat4 projection = glm::ortho(0.0f, width, 0.0f, height);
unsigned int VAO, VBO;
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 6 * 4, NULL, GL_DYNAMIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 4 * sizeof(float), 0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
glUseProgram(mTextShaderProgram->getHandle());
glUniform3f(glGetUniformLocation(mTextShaderProgram->getHandle(), "textColor"), 0.0, 0.0, 0.0);
glUniformMatrix4fv(glGetUniformLocation(mTextShaderProgram->getHandle(), "projection"), 1, GL_FALSE, glm::value_ptr(projection));
glActiveTexture(GL_TEXTURE0);
glBindVertexArray(VAO);
//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
// iterate through all characters
float x = textData.mLocation.GetX();
const float y = textData.mLocation.GetY();
for (auto c : textData.mContent)
{
auto texture = mFontTextures[c].get();
float xpos = x + texture->getGlyph()->getBearingX();
float ypos = y - (texture->getGlyph()->getHeight() - texture->getGlyph()->getBearingY());
float w = texture->getGlyph()->getWidth();
float h = texture->getGlyph()->getHeight();
// update VBO for each character
float vertices[6][4] = {
{ xpos, ypos + h, 0.0f, 0.0f },
{ xpos, ypos, 0.0f, 1.0f },
{ xpos + w, ypos, 1.0f, 1.0f },
{ xpos, ypos + h, 0.0f, 0.0f },
{ xpos + w, ypos, 1.0f, 1.0f },
{ xpos + w, ypos + h, 1.0f, 0.0f }
};
// render glyph texture over quad
glBindTexture(GL_TEXTURE_2D, texture->getHandle());
// update content of VBO memory
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), vertices);
glBindBuffer(GL_ARRAY_BUFFER, 0);
// render quad
glDrawArrays(GL_TRIANGLES, 0, 6);
// now advance cursors for next glyph (note that advance is number of 1/64 pixels)
x += (texture->getGlyph()->getAdvanceX() >> 6); // bitshift by 6 to get value in pixels (2^6 = 64)
}
glBindVertexArray(0);
glBindTexture(GL_TEXTURE_2D, 0);
}
void OpenGlPainter::renderMeshLayer(TriMesh* mesh, DrawingContext* context)
@ -193,6 +250,8 @@ void OpenGlPainter::paint(DrawingContext* context)
glViewport(0, 0, width, height);
//glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
glOrtho(0, width, 0, height, -1.0, 1.0);
//glScissor(0, 0, width, height);
//glMatrixMode(GL_PROJECTION);
//glLoadIdentity();